The Human Body
Basophil
Inflammatory response
Paralysis
Loss of the ability to make voluntary movements
central canal (haversian canal)
contains blood vessels and nerves
Myelin
Segmented wrapping of a material surrounding the axon; white, fatty substance formed by Schwann cells that wrap around some axons outside the CNS; these fibers are called myelinated fibers
Microfilaments
Thin threadlike filaments in the cytoskeleton framework
Monocyte
Largest leukocyte; aggressive phagocyte; capable of engulfing larger bacterial organisms and cancerous cells
Thoracic duct
Lymph from about 3/4 of the body eventually drains into the thoracic duct, which is the largest lymphatic vessel in the body
Lymphoid tissue
White mass of developing lymphocytes and related cells; other lymphoid organs include lymph nodes, tonsils, thymus and spleen - all of which are important structural components of the immune system because they provide immune defense and develop immune cells
Platelet
Blood clotting
Eosinophil
Defense against parasites
Fascicles
Groups of muscle fibers
Pericarditis
Inflammation of the pericardium
Palatine tonsils
Located on each side of the throat
Chemical level of organization
Often refers to atoms and molecules
Tracts
Bundles of axons in the CNS
renin-angiotensin-aldosterone system (RAAS)
Eventually produces constriction of blood vessels and thus raises BP; also triggers adrenal gland secretion of aldosterone, which promotes water retention and thus increases total. Blood volume-also contributing to a rise in BP
gluteus maximus
Forms the outer contour and much of the substance of the buttock; important extensor of the thigh and supports the torso in the erect position
Anabolism
Building up of amino acids to form tissue proteins; promotes normal growth
Embolus
If part of the clot dislodges and circulates through the bloodstream, the dislodged part is called an embolus
Sperm
Male sex cells produced by some of the cells of the testes
Apnea
If breathing stops completely for a brief of period, regardless of cause
Melatonin
Inhibits tropic hormones that affect the ovaries; thought to be involved in regulating the onset of puberty and the menstrual cycle in women; levels increase during the night and decrease during the day which is an important timekeeping mechanism for the body's internal clock and sleep cycle; supplements are now widely used to help induce sleep or reprogram the sleep cycle as a treatment for jet lag
Bicuspid valve/mitral valve
L AV valve and is located between the L atrium and ventricle
lumbar vertebrae
L1-L5; lower back
Semen
Liquid portion of the male reproductive fluid produced by other cells in the testes, male reproductive ducts, and glands
Cytokinesis
The division of the plasma membrane and cytoplasm surrounding the nucleus
Hypothyroidism
Undersecretion of thyroid hormones; can be caused by and result in a number of different medical conditions
Blood circulation
Self-explanatory but it means that blood flows through vessels that are arranged in a complete circuit/circular pattern
feedback loop
Self-regulation; control system in the body
Hydrolysis
Water (hydro) disrupts the bonds in large molecules, causing them to be broken down into smaller molecules (lysis); virtually the reverse of dehydration synthesis
Ventral Cavities
Cavities located in a ventral position in the body
Mastication
Chewing; muscles of mastication are responsible for closing the mouth and producing chewing movements; as a group, they are among the strongest muscles in the body
vasoconstriction
narrowing of blood vessels; this helps temporary close any gaps in the vessel wall and reduces local blood flow until other measures come into play; pressure applied from outside the wound by a first responder often enhances this effect
Temporal
Assists the masseter in closing the jaw; 2nd of the 2 largest muscles in the muscles of mastication group
Neuron
Nerve cell; each neuron consists of a main part called the cell body, one or more branching projections called dendrites and one elongated projection known as an axon; 3 major types of neurons: sensory, motor and interneuron
Physiology
The study of the functions of living organisms and their parts
Endoneurium
A thin wrapping of fibrous connective tissue surrounding each axon in a nerve
Sacrum
5 fused vertebrae; in child, they are 5 separate
Carbon Dioxide (CO2)
About 10% of the total amount of carbon dioxide in blood is carried in the dissolved form; it is this CO2 that produces the PCO2 of blood plasma; however, all CO2 in the blood must pass through the dissolve state before moving in or out of any of the other states
Anuria
Absence of urine
Nervous System
All of the organs within it work together to monitor and regulate the overall functioning of the body
orbicularis oris
Also called the kissing muscle; puckers the lips
B lymphocyte
Antibody production
cervical vertebrae
C1-C7; first set of seven bones, forming the neck
Atlas
C1; a ring made up of an anterior arch and posterior arch; the superior articular processes join with the processes called occipital condyles on the base of the skull
Body
Central portion of the stomach
Electrolytes
Compounds that form ions when dissolved in water
CT
Computed topography
Directional terms
Describing relative positions of body parts
Root of the tooth
Fits into the bony socket that surrounds it in either the upper or lower jaw bone
granular leukocytes
Have a life span of only a few days
Hypertonic
Having a higher concentration of solute than another solution.
Upper esophageal sphincter (UES)
Helps prevent air from entering the tube during respiration
Short bone
I.e. carpals or wrist bone
Calcitonin (CT)
Increases mineralization of bone and thus reduces blood calcium; from the thyroid gland
olecrannon fossa
Large depression on the surface of the humerus; prevents the "hinge" of the elbow to extend beyond a straight-arm position
Parietal layer
Lines the walls of the body cavity
Serum
Plasma minus its clotting factors, fibrinogen and prothrombin;
Dissection
Process of cutting apart in order to isolate and study the structural components/parts of the human body
Collagen
Protein that forms microscopic twisted ropes within the matrix of many tissues; gives the tissue flexible strength
Gyri
Ridges/convolutions forming the cerebrum
Oliguria
Scanty urination
Spirometer
Special device used to measure the amount of air exchanged in breathing
Pia mater
The innermost membrane covering the spinal cord
arachnoid mater
The membrane between the dura and the pia mater; resembles a cobweb with fluid in its spaces; arachnoid means "like a spider web"; comes from Arachne, the Greek word for spider
Atomic mass
The number of protons and neutrons in an atom
Routes of circulation
Various sets of artery-capillary-vein pathways
Renal medulla
inner portion of the kidney
Alkalosis
pH above 7.45
Flat bones
I.e. frontal or skull bone, sternum (breastbone), ribs; have a simpler structure than most long bones; have a layer of cancellous bone between outer layers of compact bone
long bones
I.e. humerus or arm bone
Type 1 diabetes mellitus
If the pancreatic inlets secrete too little insulin, less glucose leaves the blood to enter the cells, so the blood glucose can increase up to as high as 3 times the normal amount;
Agranular leukocytes (agranulocytes)
Includes lymphocytes and monocytes
Dissociate
Ionic compounds easily dissolve in water because water molecules are attracted to ions and wedge between them forcing them apart; the compounds dissociate to form free ions
Vertebrae
24 separate bones that make up the vertebral column/spine; connected in such a way that they form a flexible, curved rod; they have several well defined parts
Oblique plane
A cut along a plane that is not parallel to the other types of planes
Thymosin
A group of several hormones that play an important role in regulating the development and formation of T cells
Antibody
A substance made by the body in response to stimulation by an antigen; defined according to its function, an antibody is a substance that reacts with the antigen that stimulated its formation
carbaminohemoglobin (HbCO2)
About 20% of the total CO2 transported in the blood; formed by the union of carbon dioxide and hemoglobin; the formation of this compound is accelerated by an increase in PCO2 - as the extra dissolved CO2 binds to hemoglobin; likewise, formation of HbCO2 is slowed or even reversed by a decrease in PCO2
Bases of DNA
Adenine, Thymine, Guanine, Cytosine; these are called bases because by themselves they have a high pH and chemicals with a high pH are called "bases"
Expiratory reserve volume (ERV)
Amount of air that can be forcibly exhaled after expiring the tidal volume
Adrenal glands
An adrenal gland curves over the superior surface of each kidney; from the surface, an adrenal gland only appears to be one organ but it is really 2 separate endocrine glands: the adrenal cortex and the adrenal medulla
Hypertrophy
An increase in muscle size due to exercise
Reticular tissue
Another type of fibrous, connective tissue; thin, delicate webs of collagen fibers called reticular fibers; reticular means "netlike"; found in bone marrow, where it helps support cells of the blood-forming hematopoietic tissue; also found in the spleen and lymph nodes, where it supports developing cells of the immune system
Repolarization
Begins just before the relaxation phase of cardiac muscle activity
Supine position
Body is lying facing upward
Memory cells
Can secrete antibodies but don't immediately do so; remain in reserve in the lymph nodes until they're contacted by the same antigen that led to their formation; then, very quickly, the memory cells develop into plasma cells and secrete large numbers of antibodies; memory cells seem to "remember" their ancestor-activated B cell's encounter with its appropriate antigen; they stand ready to produce antibodies that will combine with this antigen
Thrombus
Clot which may form due to blood flowing over a rough surface; unfortunately, rough spots caused by endocarditis or injuries to blood vessel walls often cause the release of platelet factors; the result is often the formation of a fatal blood clot
pectoral girdle/shoulder girdle
Composed of the scapula and the clavicle; connects the upper extremity to the axial skeleton
Transverse canals (Volkmann canals)
Connect central canals to one another
Submucosa
Connective tissue layer that lies just below the mucosa; contains many blood vessels and nerves
appendicular skeleton
Contains 126 of the 206 bones that make up the skeleton; Made up of the bones of upper and lower extremities/appendages; consists of the shoulder, pectoral girdles, arms, wrists, hands,. Hip, pelvic girdles, legs, ankles, and feet
Elastic cartilage
Contains few collagen fibers but large numbers of very fine elastic fibers that give the matrix material a high degree of flexibility; found in the external ear and in the voice box/larynx
chemical formula
Contains symbols that represent each element in the molecule; number of atoms of each element in the molecule is expressed as a subscript after the elemental symbol
tonic contraction (muscle tone)
Continuous low-strength muscle contraction; since relatively few of a muscle's fibers shorten at once in a tonic contraction, the muscle doesn't shorten and no movement occurs; tonic contractions don't move any body parts; they do hold muscles in position
Systole
Contraction of the heart
quadriceps femoris
Covers the upper thigh; 4 thigh muscles - the rectum femoris and 3 vastus muscles -extend the leg; one component has its origins on the pelvis and the remaining 3 originate on the tibia;
Addison disease
Deficiency or hyposecretion of adrenal cortex hormones; causes reduced cortical hormone levels resulting in muscle weakness, reduced blood sugar, nausea, loss of appetite, and weight loss; President JFK suffered from this
myxedema
Deficient thyroid hormone secretion later in life; leads to lessened mental and physical vigor, weight gain, hair loss, and swelling of tissues
Chemically stable
Describes an atom when its energy level is "full" (when its energy shells have the maximum number of electrons they can hold)
upper extremity
Divided into arm, forearm ,wrist and hand components
Connective tissue membranes
Do NOT contain epithelial components
Prolactin (PRL)
During pregnancy, stimulates the breast development necessary for lactation; also, after a baby is born, the woman's prolactin stimulates the breasts to start secreting milk, a function suggested by lactogenic hormone, another name for PRL
Auricle
Earlike extension of the atria
Lipids
FATS are lipids that are stored at room temperature; OILS are liquid at room temperature
Thrombosis
Formation of a blood clot
Tibia/shinbone
Forms a rather sharp edge or crest along the front of your leg
Ovaries
Gonads of women; they have a puckered, uneven surface; each weighs about 3 grams; the ovaries resemble large almonds in size and shape; they are attached to ligaments in the pelvic cavity on each side of the uterus; embedded in a connective. tissue matrix just below the outer layer of each ovary in a newborn baby girl are about 1 million follicles; each follicle contains an oocyte
Water
H20; inorganic compound; essential to life; most abundant compound found in and around each cell; typically a solvent
Enamel
Hardest tissue in the body; covers the outside of the crown; ideally suited to withstand the grinding that occurs during the chewing of hard and brittle foods
hypercalcemia
Harmful excess of calcium in the blood
granular leukocytes (granulocytes)
Have stained granules; include neutrophils, eosinophils, and basophils
juxtamedullary nephrons
Have their renal corpuscles near the junction between cortex and medullary layers; have nephron loops that dip far into the medulla; have an important role in concentrating urine
Cardiovascular physiology
Heart, blood, blood vessels and issues arising
tibalis anterior
Located on the anterior or front surface of the leg; dorsiflexes the foot
Tonsils
Masses of lymphoid tissue that are located in a protective ring under the mucous membranes in the mouth and back of the throat; help protect against bacteria that may invade tissues in the area around the openings between the nasal and oral cavities; serve as the first line of defense from the exterior and as such are subject to chronic infection; in rare cases, they may be removed surgically if antibiotic therapy is not successful at treating the chronic infection or if swelling impairs breathing
hilium of kidney
Medial indentation; where vessels, nerves, and the ureter connect with the kidney; an avg. kidney measures 4.3 X 2.7 X 1.2 in; there is a tough fibrous capsule that forms the exterior wall
Arches of the foot
Medial longitudinal arch, lies on the inside part of the foot Lateral longitudinal arch, lies along the outer edge of the foot Transverse/metatarsal arch, lies across the ball of the foot
Three-neuron reflexes
More complex type of responses; an interneuron, in addition to a sensory neuron and a motor neuron, is involved; the end of the sensory neuron's axon synapses with an interneuron before chemical signals are sent across a second synapse, resulting in conduction through the motor neuron; because of the presence of an interneuron, 3-neuron reflex arcs only have 2 synapses
tetanic contraction
More sustained and steady response than a twitch; produced by a series of stimuli bombarding the muscle in rapid succession; not necessarily a maximal contraction in which each muscle fiber responds at the same time; in most cases, only a few groups of muscle fibers undergo contractions at any one time
Embolism
Obstruction of a blood vessel by a clot of blood or foreign substance
hyperthyroidism
Oversecretion of the thyroid hormones; dramatically increases the metabolic rate; people who suffer from this lose weight, are irritable, have an increased appetite, and often show profusion of the eyeballs due in part to edema of tissue at the back of the eye socket
Tracheostomy
Procedure involves the cutting of an opening into the trachea; this may be performed so that a suction device can be inserted to remove secretions from the bronchial tree or so that an intermittent positive-pressure breathing (IPPB) machine can be used to improve ventilation of the lungs
intramembranous ossification
Process of bones forming by calcification of fibrous membranes, i.e. skull bones; as it progresses, a hard bone plate forms a complete flat bone
immune system
Protective "safety net"
Twitch
Quick jerky response to a stimulus; can be seen in isolated muscles during research, but they play a minimal role in normal muscle activity; in order to accomplish the coordinated and fluid muscular movements needed for most daily tasks, muscles must contract in a smooth and sustained way
tricuspid valve
R AV valve and is located between the R atrium and ventricle
Myeloid tissue
Red bone marrow; in the adult, it is found chiefly in the sternum, ribs, and coral (hip) bones; a few other bones such as the vertebrae, clavicles, and cranial bones also contain small amounts of this tissue; forms all types of blood cells except lymphocytes
Secretion
Release of digestive enzymes and other products into the lumen of the GI tract; in chemical digestion, large nutrient molecules are reduced to smaller molecules
Hemorrhagic anemia
Results from a decrease in the number of RBCs caused by hemorrhage resulting from accidents or bleeding ulcers
Scapula
Shoulder blade
Tropic hormones
Stimulate another endocrine gland to grow and secrete its hormones
Scientific method
Systematic approach to discovery
Residual volume (RV)
The air that remains in the lungs after the most forceful expiration
Anaphase
The beadlike centromeres break apart; the individual chromosomes, now identified again as chromosomes, move away from the center of the cell; movement of chromosomes occurs along spindle fibers toward the centrioles; the chromosomes are being pulled to opposite ends of the cell; at the end of anaphase, the cleavage furrow can be seen for the 1st time; it begins to divide the plasma membrane and cytoplasm into 2 daughter cells
Parasympathetic postganglionic neurons
The dendrites and cell bodies lie in these outlying parasympathetic ganglia, and their short axons extend into the nearby structures; each parasympathetic preganglionic neuron synapses only with postganglionic neurons to a single effector; parasympathetic stimulation frequently involves response by only one organ
Fascia
The fibrous material that helps bind the skin, muscles, bones and other organs of the body together
Olecranon
The large bony process of the ulna
Bilateral symmetry
The left and right sides of the mirror roughly mirror each other
Threshold stimulus
The minimal level of stimulation required to cause a fiber to contract
Respiratory tract
The pathway of air flow; often divided into upper and lower tracts/divisions to help with describing symptoms associated with common respiratory problems such as a a cold; the organs of the upper respiratory tract are located outside of the thorax (chest cavity) whereas those in the lower tract are located almost entirely within it
protein synthesis
The process of transferring genetic information from the nucleus into the cytoplasm, where proteins are actually produced, requires transcription and translation
Hyposecretion
Too little hormone
Eversion
Turns the ankle in the opposite direction, so that the bottom of the foot faces toward the side of the body
Osteoclasts
bone-reabsorbing cells; releases acid that dissolves the calcium crystals which has 2 effects: it removes the hard bone matrix and it releases calcium ions from bone tissue to diffuse into the bloodstream
radius and ulna
forearm bones; articulate with each other and with the distal end of the humerus at the elbow joint; they also touch each other distally where they articulate with the bones of the wrist
external respiration
makes the exchange of gases between air in the lungs and in the blood possible
neuromuscular junction (NMJ)
point of contact between the nerve ending and the muscle fiber
Solutes
substance dissolved in a solution; without transporters, they could not diffuse through cell membranes
atomic number
the number of protons in the nucleus of an atom
Penis
the organ, that when made stiff and erect by the filling of its spongy or erectile tissue components with blood during sexual arousal, can enter and deposit sperm in the vagina during intercourse; has 3 separate columns of erectile tissue in its shaft: one column of corpus spongiosum, which surrounds the urethra, and 2 columns of corpora cavernosa, which lie dorsally; at the distal end of the shaft of the penis is the enlarged glans penis (glans); the external urinary meatus is the opening of the urethra at the tip of the glans
thoracic vertebrae
the second set of 12 vertebrae; form the outward curve of the spine and are known as T1 through T12
Microtubules
tiny hollow tubes of protein
goblet cells
"Open spaces" among the cells; they produce mucus
Fascicles
Groups of these wrapped axons
Corpus luteum
Mainly secretes progesterone but also some estrogen
Sutures
immovable joints that unite cranial bones; the lamboidal suture with the occipital bone, the squamous suture with the temporal bone and part of the sphenoid, and the coronal suture with the frontal bone
luteinizing hormone (LH)
in the female, stimulates ovulation; in the male, stimulates testosterone secretion
Central nervous system (CNS)
the brain and the spinal cord which occupy a midline/central location in the body; the brain is protected in the cranial cavity of the skull and the spinal cord is surrounded by the vertebral column; the brain and spinal cord are also protected by 3 membranes called meninges
Lyse
the death of a cell by bursting
isotonic contraction
produces movement at a joint; with this type of contraction, the muscles change length, and the insertion end moves relative to the point of origin; 2 types of isotonic contraction: concentric and eccentric; examples include breathing, running, walking, lifting and twisting, and most body movements
LDL (low density lipoprotein)
"bad cholesterol" that brings cholesterol to the body cells
Matter
Anything that has mass and occupies space
Distal
Means "away from or farthest from the trunk or the point of origin of a body part
Mediastinum
Mid portion is a subdivision of the thoracic cavity
internal oblique
Middle layer of the muscle in the anterolateral abdominal wall
Serosa
Outermost covering or coat of the digestive tube; in the abdominal cavity, this serosa covering is called the visceral peritoneum
Oligodendrocytes
help hold nerve fibers together and produce the fatty myelin sheath that envelops nerve fibers. Located in the brain and spinal cord
Reproductive physiology
Concerns the reproductive cycle
visceral layer
Covers the organs in those cavities
Fundus
Enlarged, curving base to the left of and above the opening of the esophagus into the stomach
reticular formation
Formed by small bits of gray matter mixing closely and intricately with white matter; reticular means netlike; gray matter forms the interior core of the spinal cord, and white matter surrounds it; in the spinal cord, gray and white matter don't intermingle
ionic bond
Forms between an atom that has only 1 or 2 electrons in the outermost level (which usually holds 8) and an atom that needs only 1 or 2 electrons to fill its outer level. The atom with 1 or 2 electrons "donates" its outer shells electrons to the atom that needs 1 or 2
Neutrophil
Immune defense (phagocytosis)
Medial
Means "toward the midline of the body"
Ejaculatory duct
Once in the abdominal cavity, the vas deferens extends over the top and down the posterior surface of the bladder, where it joins the duct from the seminal vesicle to form the ejaculatory duct
Elimination
Ridding the body of waste material (feces) that result from the digestive process; the large intestine, part of the digestive system, serves as an organ of elimination
Pontine respiratory group (PRG)
Several control centers in the pons; seem to provide input to the DRG and thus help modulate the basic rhythm as needed under a variety of conditions in the body
Gametes
Sex/reproductive cells needed to form the offspring; the ovum and sperm fuse during the process of fertilization
Arrangement of epithelial cells
Simple - single layers of cells of the same shape; stratified - many layers of cells, named for the shape of cells in the outer layer
red bone marrow
Site of blood cell formation; soft connective tissue inside the hard walls of some bones that produce both red and white blood cells
Pituitary stalk
Stem-like structure; attaches the gland to the undersurface of the brain; attaches the pituitary body to the hypothalamus
Proteomics
The study of all the proteins encoded by each of the genes of the human genome
Endocardium
Thin layer of very smooth tissue that lines each chamber of the heart
Strong bases
Produce a very low relative H+ concentration and have a very high pH value-far above 7
Mastication
Chewing; involves involuntary movements that result in formation of a ball (bolus) of food in the mouth that is then moved involuntarily through the oropharynx and into the esophagus, and, finally, into the stomach
Catecholamines
Examples are dopamine, norepinephrine, epinephrine; they play a role in sleep, motor function, mood, and pleasure recognition
Simple columnar epithelium
Found lining the inner surface of the stomach, intestines, and some areas of the respiratory and reproductive tracts; simple columnar cells are arranged in a single layer lining the inner surface of the colon/large intestine; these epithelial cells are taller than they are wide and the nuclei are located toward the bottom of each cell; regular columnar cells specialize in absorption
Nephron
Functional unit of the kidney; more than a million microscopic units make up the kidney's interior; shape is unique, unmistakable, and admirably suited to its function of producing urine; looks a little like a tiny funnel with a very long stem, but it is an unusual stem in that it is highly convoluted (has many bends in it); composed of 2 principle components: the renal corpuscle and the renal tubule; urine from the collecting ducts exits from the pyramid through the Paiella and enters the calyx and renal pelvis before flowing into the ureter
Size and shape of cells
Human cells can only be seen through a microscope, but they can vary considerably in size i.e. an ovum has a diameter of 150 micrometers but red blood cells have a diameter of 7.5 micrometers; cells differ even more notably In shape - they can be flat, brick-shaped, threadlike and even irregular shapes
Melatonin
Known as the "timekeeping hormone" because it helps keep the body's clock "on time" with the daily, monthly, and seasonal cycles of sunlight and moonlight
Molecule
Particles of matter that are composed of one or more atoms; larger chemical units; some molecules are made of several atoms of the same element
Chordate tendineae
Stringlike structures that attach the AV valves to the wall of the ventricles
Antigens
Substance that can stimulate the body to make antibodies; almost all substances that act as antigens are foreign molecules-often on the surfaces of bacterial cells and viruses; they are not the body's own natural molecules but are molecules that have entered the body from the outside by means of infection, transfusion or other method
Dorsal
Term used for humans who walk in an upright position; means "toward the side of the body or away from its midline"
integumantary system
The skin and its appendages - hair, nails, and the skin glands; integument is another name for the skin, and the skin itself is the principal organ of the integumentary system
ilium, ischium, pubis
fuse to form the coxal bone
anesthesia
loss of sensation
erythrocyte
oxygen and carbon dioxide transport; circulate for up to 4 months before they break apart and their components are removed from the bloodstream by the spleen and liver
Pulse
What you feel is an artery expanding and then recoiling alternately because of the changes of arterial BPs that result from the L ventricle contracting and relaxing; valuable clinical sign which can provide info about the rate, strength, and rhythmicity of the heartbeat and BP; easily determined with little or no danger or discomfort and "pulse points" are located in 9 different areas
Accessory organs of reproduction in men
A series of passageways or ducts that carry the sperm from the testes to the exterior; additional sex glands that provide secretions that protect and nurture sperm; the external reproductive organs called the external genitals
Nerve
A group of peripheral nerve fibers (axons) bundled together like strands in a cable; they usually have a myelin sheath; because myelin is white, peripheral nerves often look white
Acethylcholine(ACh)
A neurotransmitter that is released at some of the synapses in the spinal cord and at neuromuscular junctions
Tissue typing
A procedure performed prior to transplanting an organ from one individual to another
Midbrain
3rd of 3 structures that make up the brainstem
Tetanus
A sustained contraction which occurs as a result of contractions "melt"ing together; i.e. about 30 stimuli per second evoke a tetanic contraction in certain types of skeletal muscle; not necessarily a maximal contraction in which each muscle fiber responds at the same time; in most cases, only a few groups of muscle fibers undergo contractions at any one time
Vasomotor mechanism
Adjustment of muscle tension in vessel walls to control BP and therefore blood flow
Dorsal respiratory group (DRG)
Adjusts the breathing rhythm when blood pH or carbon dioxide levels change-as they would during exercise
ventricular systole
After the ventricles fill with blood, they, too, contract together
Prone position
Body is lying facing downward
alimentary canal
Irregular tube, open at both ends; Principal structure of the digestive system
cortical nephrons
Located almost entirely in the renal cortex; typical of about 85% of all nephrons
Testosterone
Male sex hormone; secreted directly into the blood by interstitial cells in the testes; male endocrine glands; the "masculinizing hormone"; responsible for maturation of the external gentians, beard growth, changes in voice at puberty, and for the muscular development and body contours typical of a male
supination and pronation
Refer to hand positions that result from rotation of the forearm; supination results in a hand position with the palm turned to the anterior and pronation occurs when you turn the palm of your hand so that it faces posteriorly
Myophysiology
The operation of muscles
amino acids
Very large molecules composed of basic units; in addition to containing carbon, hydrogen, and oxygen, all amino acids contain nitrogen
Thymosins
A group of hormones secreted by the thymus that influence the development of T cells
Plexus
A network of intersecting or "braided" branches that form a single peripheral nerve
Nucleoplasm
A special type of cell material in the nucleus that is surrounded by the nuclear envelope; contains the nucleolus and chromatin granules
Polysaccharides
Carbohydrates that are made up of more than two monosaccharides; examples are starch and glycogen
carbaminohemoglobin (HbCO2)
Formed by Carbon dioxide which may attach to the amino acids within hemoglobin's alpha and beta chains; transports about 20% of the carbon dioxide produced as a waste product of cellular metabolism to the lungs for disposal into the external environment; about 10% of the CO2 is transported in the blood dissolved in plasma; approx. 70% of CO2 carried in the blood is converted in RBCs to bicarbonate for its journey to the lungs for excretion
Microvilli
Further increase the surface area of each villus for absorption of nutrients
Nodes of Ranvier
Gaps between adjacent Schwann cells
tenosynovitis
Inflammation of the tendon sheath; can be painful and the swelling characteristic of this condition can limit movement in affected parts of the body, i.e. swelling of the tendon sheath around tendons in an area of the wrist known as the carpal tunnel can limit movement of the wrist, hand, and fingers
Leukopenia
Is used to describe an abnormally low WBC count (less than 5000 WBCs of blood); does not occur often; malfunction of blood-forming tissues and cells and some diseases affecting the immune system, such as AIDS, may lower WBC numbers
agranular leukocytes
May live for more than 6 months
disuse atrophy
Muscles usually shrink in mass due to prolonged inactivity
ventral respiratory group (VRG)
Provides the basic rhythm generator for breathing
Oxytocin (OT)
Secreted at high levels by a woman's body before and after she has a baby; it stimulates contraction of smooth muscle of the pregnant uterus and I'd believed to initiate and maintain labor; also causes the glandular cells of the breast to release milk into ducts from which a baby can easily obtain it by sucking; in short, it stimulates "milk let-down"; also thought to enhance social bonding - a function helpful in supporting the mother-infant bond
hypoventilation
Slow and shallow respirations
Fast fibers (white fibers)
They have a low red myoglobin content; best suited for quick powerful actions because even though they fatigue quickly, they can produce a great amount of ATP quickly; well suited to sprinting and weight lifting; muscles that move the fingers have a high proportion of fast fibers - helpful when playing a computer game or a musical instrument
myocardial infarction (MI)/also referred to as "heart attack"
Tissue death; deprived of death, these cells soon become damaged or die; common cause of death during middle and late adulthood; recovery from a myocardial infection is possible if the amount of heart tissue damaged was was small enough so that the remaining undamaged was small enough so that the remaining undamaged heart muscle can pump blood effectively enough to supply the needs of the rest of the heart and the body
Epineurium
Tough fibrous sheath that covers the whole nerve
Renal cortex
Outer part of the kidney (the word cortex comes from the Latin word for "bark" so the cortex of an organ is its outer layer)
Atrial systole
When the heart "beats" first, the atria contract simultaneously
sesamoid bone
"Like a sesame" or round which may develop within a tendon; i.e. the kneecap (patella) which develops within the patellar tendon
antagonist muscle
As prime movers and synergist muscles at a joint contract, these muscles relax; when they contract, they produce a movement opposite to that of the prime movers and their synergist muscles
Prothrombin activator
As vessels constrict, damaged tissue cells release various clotting factors into the plasma; these factors rapidly react with other factors already present in the plasma; an injury makes a rough spot with exposed collagen fibers; this attracts platelets to the site which become "sticky" at the point of injury and rapidly accumulate near the break in the blood vessel, forming a soft, temporary platelet plug; as the platelets accumulate, they release additional clotting factors, forming even more prothrombin activator-a kind of self-amplifying, positive -feedback response; if the normal amount of blood calcium is present, prothrombin activator triggers the next step of clotting by converting prothrombin (a protein in normal blood) to thrombin; in the last step, thrombin reacts with fibrinogen (a normal plasma protein) to change it to a fibrous gel called fibrin; fibrin looks like a tangle of fine threads with RBCs caught in the tangle; the clotting mechanism contains clues for ways to stop bleeding by speeding up blood clotting, i.e. applying gauze to a bleeding surface; physicians sometimes prescribe vitamin K before surgery to make sure that the patient's blood will clot fast enough to prevent hemorrhage; Vitamin K stimulates liver cells to increase the synthesis of prothrombin; more prothrombin in blood allows faster production of thrombin during clotting and thus faster clot formation
arteries and arterioles
Distribute blood from the heart to capillaries in all parts of the body; by constricting or dilating, arterioles help maintain arterial blood pressure at a normal level
nerve impulses/action potentials
During every moment, nerve impulses speed over neurons to and from our spinal cords and brains; if they stop, life stops; only neurons can provide the rapid communication between cells that is necessary for maintaining life; can travel over trillions of routes; routes are made up of neurons because they're the cells that conduct impulses; these routes are also called neuron pathways; one widely accepted definition is that a nerve impulse is a self-propagating wave of electrical disturbance that travels along the surface of a neuron's plasma membrane; they need to be initiated by a stimulus, a change in the neuron's environment; pressure, temperature, and chemical changes are the usual stimuli; cannot go backwards during the brief moment of repolarization; thus, a self-propagating wave of electrical disturbance - a nerve impulse - travels continuously in one direction across the neuron's surface; also called action potentials because each one is a difference in charge that usually triggers an action by the cell - in this case, transmitting the impulse itself
Flexion
A movement that makes the angle between 2 bones at their joint smaller than it was at the beginning of the movement; most flexions are commonly described as bending; flexors produce many of the movements used for walking, sitting, swimming, typing, and many other activities
Seminiferous tubule
A narrow but long and coiled seminiferous tubule comprises a lobule; these coiled structures form the bulk of the testicular tissue mass; long duct with a central lumen or passageway; sperm develop in the walls of the tubule and are then released into the lumen and begin their journey to the exterior of the body
Anemia
A number of different disease conditions caused by an inability of the blood to carry sufficient oxygen to the blood cells; can result from an inadequate numbers of RBCs or a deficiency of normal hemoglobin; anemia can occur if the hemoglobin in RBCs is inadequate even if adequate numbers of RBCs are present
Clone
Family of many identical cells, all descended from one cell; made up of 2 types of cells: plasma (effector) cells and memory cells
Slow fibers (red fibers)
Have a high content of oxygen-storing myoglobin; best suited to endurance activities such as long-distance running because they do not fatigue easily; muscles that maintain body position-posture-have a proportion of slow fibers
Intermediate fibers
Have characteristics between the extremes of slow and fast fibers; found in muscles like the calf muscle which is used for posture and occasional brief, powerful contractions such as jumping
Sympathetic preganglionic neurons
Have dendrites and cell bodies in the gray matter of the thoracic and upper lumbar segments of the spinal cord; sympathetic system has also been referred to as the thoracolumbar system; axon leaves the spinal cord in the anterior (ventral) root of a spinal nerve; it next enters the spinal nerve but soon leaves it to extend to and through a sympathetic ganglion and terminate it in a collateral ganglion; there, it synapses with several postganglionic neurons whose axons extend to terminate in visceral effectors; branches of the preganglionic axon may ascend or descend to terminate in ganglia above and below their point of origin; all sympathetic preganglionic axons therefore synapse with many postganglionic neurons, and these frequently terminate in widely separated organs; sympathetic responses are usually widespread, involving many organs
parathyroid hormone(PTH)
Increases the concentration of calcium in the blood-the opposite effect of the thyroid gland's calcitonin; stimulates mineral-dissolving osteoclast cells in bone tissue to increase their breakdown of bone's hard matrix, a process that frees the calcium stored in the matrix; the released calcium then moves out of bone into blood and this in turn increases the blood's calcium concentration; this is a matter of life and death importance because our cells are extremely sensitive to changing amounts of blood calcium; they can't function normally with too much or too little calcium, i.e. if there is too much calcium, brain and heart cells stop working properly; if there is too little calcium, nerve cells become overactive, sometimes to the point where they bombard the muscles with so many impulses that they cause spasms
Adrenal medulla
Inner part of an adrenal gland and it is made up of secretory nervous tissue; secretes the hormones epinephrine (Epi)/adrenaline and norepinephrine (NR);a physiologist might say that the body resists stress by making stress responses; responds very quickly to stress because nerve impulses conducted by sympathetic nerve fibers stimulate the adrenal medulla; when stimulated, it squirts Epi and NR into the blood; these hormones produce the body's "fight or flight" response to danger; this means you would be ready for strenuous activity to either resist or avoid the stressor; Epi prolongs and intensifies changes in body function brought about by the stimulation of the sympathetic division of the ANS; Epi and NR are neurotransmitter substances that are released by sympathetic/adrenergic fibers; in stress conditions, the hypothalamus acts on the anterior pituitary gland to cause the release of ACTH, which stimulates the adrenal cortex to secrete glucocorticoids; at the same time, the sympathetic subdivision of the ANS is stimulated with the adrenal medulla, so the release of Epi and NR occurs to help the body respond to the stressful stimuli
Triglycerides
Lipid molecules formed by a glycerol unit (head) joined to three fatty acids (tail); useful for storing energy in cells for later use; triglycerides stored in fat tissue also provide helpful "padding" around organs and under the skin to stabilize and protect body structures
Soft palate
Located above the the posterior or rear portion of the mouth; soft because it consists mostly of muscle
Aortic SL valve
Located at the beginning of the aorta and allows blood to flow out of the L ventricle up into the aorta but prevents backflow into this ventricle
Pulmonary SL valve
Located at the beginning of the pulmonary artery and allows blood going to the lungs to flow out of the R ventricle during systole but prevents it from flowing back into the ventricle during diastole
Semilunar (SL) valves
Located between each ventricular chamber and its large artery that carries blood away from the heart when contraction occurs; the ventricles contract together; therefore, the 2 SL valves open and close at the same time
Heart
Located between the lungs in the lower mediastinum; often described as a triangular organ, shaped and sized roughly like a closed fist; positioned in the thoracic cavity between the sternum in front and the bodies of the thoracic vertebrae behind; hollow, not solid; portion divides it into R and L sides; contains 4 cavities or hollow chambers; when the heart beats (contracts), the atria contract first forcing blood into the ventricles; once filled, the ventricles contract and force blood out of the heart; for the heart to be efficient in its pumping action, the direction of blood flow must be directed and controlled; this is accomplished by 4 sets of valves located at the entrance and near the exit of the ventricles
Humerus
Long bone of the arm; 2nd longest bone in the body; attached at the concave glenoid cavity of the scapula at its proximal end where it is held in place and permitted to move by a group of muscles that are together called the rotator cuff; the distal end of the humerus articulates with the 2 bones of the forearm at the elbow joint
Right lymphatic duct
Lymph from the right upper extremity and from the R side of the head, neck, and upper torso flow into the R lymphatic ductt
Lacteals
Lymphatic capillaries in the wall of the small intestine; they transport fats obtained from food nutrients to the bloodstream
Muscularis
Made up of 2 or 3 layers of muscle tissue; these muscle layers have an important role to play in producing motility/movement of the GI tract during the digestive process
antidiuretic hormone (ADH)
Major regulator of fluid balance in the human body; accelerates the reabsorption of water from urine in kidney tubules back into the blood; with more water moving out of the tubules into the blood, less urine leaves the body; anti means "against" and diuretic means "increasing the volume of urine excreted"; ADH acts to decrease urine volume and prevent dehydration
Sperm
Male sex cells; Smallest and most unusual cells in the body; term comes from Latin spermatozoon meaning "seed animal"; this is because, somewhat like a seed, each sperm cell is part of the reproductive process; and each sperm cell has a tail and moves independently somewhat like a microscopic animal; all of the characteristics that a baby will inherit from its father at fertilization are contained in the nuclear chromosomes found in each sperm head; each sperm has a mid piece and an elongated tail; mitochondria in the midpiece release ATP to provide the energy source for the tail movements required to propel the sperm and allow them to swim for relatively long distances through the female reproductive ducts; the tail is actually a flagellum
Fluctuations in arterial BP
No one's BP stays the same all the time, i.e. it increases with strenuous exercise which increases circulation to bring more blood to muscles each minute and thus supplies them with more oxygen and nutrients for more energy; what is "normal" varies somewhat among individuals and also varies with age
white matter
Myelinated bundles of axons located in the brain and spinal cord
Zygote
New offspring cells that forms during fertilization; after many complicated and amazing developmental stages, it ultimately develops into a new individual organism
Thrombus
When a clot stays where it is formed
"All or none"
When a muscle fiber is subjected to a threshold stimulus, it contracts completely
covalent bond
a bond formed when atoms share one or more pairs of electrons; not easily broken; do not break apart in water
Mitosis
Process of dividing the replicate genetic material (the DNA) of the nucleus in an orderly way so that each resulting daughter cell has a complete identical set; results in the production of identical new cells; during developmental years, the addition of cells helps tissues and organs grow; during this period of growth, mitosis also allows groups of similar tissues to differentiate or develop into different tissues; in an adult, mitosis replaces cells that have become less functional with age or have been damaged and destroyed by illness or injury
asexual reproduction
Requires only one parent who produces an offspring genetically identical to itself
angina pectoris
Severe chest pain that occurs when the myocardium is deprived of adequate oxygen; often a warning that the coronary arteries are no longer able to supply enough blood and oxygen to the heart muscle
Phospholipids
Similar to triglycerides but have phosphorus-containing units called phosphates in them; the phosphate at the base of the glycerol head attracts water; two fatty acid tails repel water; this structure allows them to form a stable bilateral in water that forms the foundation for the cell membrane
Neuroglia/glia
Special types of supporting cells; name is derived from the Greek word meaning "glue"; one function is to hold the functioning neurons together and protect them; they perform many different functions, including the regulation of neuron function; not only do they act as "glue" in the physical sense but they help bring the various functions of nervous tissue together into a coordinated whole
Differential WBC count
Special type of white blood cell count; reveals more information than simply counting the total number of all of the different types of WBCs in a blood sample; the proportions of each type of blood cell are reported as percentages of the total WBC count; because specific diseases affect each WBC type differently, the differential WBC count is a valuable diagnostic tool
Glycosuria
Sugar in the urine; excess sugar is filtered out of the blood by the kidneys and lost in the urine
RH-positive
The RBCs of this blood type contain an antigen called the Rh factor; if, for example, a person has Type AB, RH positive blood, the red cells contain A antigen, B antigen and the Rh factor antigen; Rh was first discovered in the blood of Rhesus monkeys
extension movement
The opposition of flexion; they make the angle between 2 bones at their joint larger than it was at the beginning of the movement; extensions are straightening or stretching movements rather than bending; extensors also function in these activities but perhaps they play their most important role in maintaining an upright posture
Blood pressure (BP)
The pressure or "push" of blood as it flows through the cardiovascular system; exists in all blood vessels but it is highest in the arteries and lowest in the veins
Diffusion
The process by which substances scatter themselves evenly throughout an openly available space; does not require addt'l energy; can be described as a trend of movement of particles down a concentration gradient - from an area of high concentration to low concentration; the key to diffusion across a membrane is the presence of pores big enough for the particles to pass through; in cell membranes, most molecules can't pass through unless there are gateways that permit it; various protein channels act as gated doorways that permit certain molecules to diffuse through them; other protein structures act as carriers that bind to the particles and carry them through to the other side of the membrane
PH
The relative measure of the hydrogen ion concentration within a solution; formula used to calculate pH units gives a value of 7 to pure water
Cardiology
The study and treatment of the heart; owes a lot to physiologist Willem Einthoven and his invention of the modern ECG n 1903; with the help of Dr. Lewis Thomas, Einthoven demonstrated and names the P,Q,R,S, and T waves and proved that these waves precisely record the heart's electrical activity; he even invented telemetry in 1905; modern versions of the machine are used today to diagnose heart disorders; biomedical engineers continue to develop refinements to ECG equipment and invent new machines to monitor heart function; engineers and designers have worked with cardiologists to develop artificial heart valves, artificial pacemakers and even artificial hearts
pineal gland
Tiny mass protruding from the back of the diencephalon and posterior to the thalamus; also called the pineal body; shaped like a small pine nut or kernel of corn; it receives sensory information about the strength of light seen by the eyes and adjusts its output of the hormone melatonin;
Canaliculi
Tiny passageways/Canals that connect the lacunae with each other and with the central canal in each osteon; nutrients pass along cell extensions of the osteocytes from the blood vessel in the central canal through the canaliculi and are distributed to all osteocytes of the osteon
Ganglia (PNS)
axons extend from these structures and terminate in peripheral "junction boxes";
diabetes insipidus
hyposecretion of ADH; a condition in which large volumes of urine are formed; dehydration and electrolyte imbalances may cause serious problems; although increased water intake can relieve mild symptoms, many cases also require administering a synthetic form of ADH
expiratory muscles
internal intercostal muscles and abdominal muscles; contract during more forceful expiration; when contracted, the internal intercostal muscles pull the rib cage inward and decrease the front-to-back size of the thorax; contraction of the abdominal muscles pushes the abdominal organs against the underside of the diaphragm, pushing it farther upward into the thoracic cavity; as the thoracic cavity decreases in size, the air pressure within it increases above atmospheric air pressure and air flows out of the lungs
withdrawal reflex
A 3-neuron arc reaction; for example, applying an irritating stimulus to the skin of the thigh initiates a 3-neuron reflex response that causes contraction of muscles to pull the leg away from the irritant
hyoid bone
A U-shaped bone located in the neck where it serves an an anchor for tongue muscles and helps support the larynx (voice box); does not form a joint with any other bone in the skeleton
Transport of carbon dioxide (CO2)
A by-product of cellular metabolism and plays an important and necessary role in regulating the pH of body fluids; however, if it accumulates in the body beyond normal limits (40-50 mmHg in venous blood), it can quickly become toxic; elimination of excess CO2 from the body occurs when it enters the alveoli and is expelled during expiration;
dehydration synthesis
A chemical reaction in which two molecules are bonded together with the removal of a water molecule.
Gingivitis
A general term for mild, localized, and often transitory inflammation of the gums or gingiva
inspiratory reserve volume (IRV)
Amount of air that can be forcibly inspired over and above a normal inspiration
cisterna chyli
An enlarged pouch-like structure in the thoracic duct that serves as a temporary holding area for lymph moving toward its point of entry into the veins
Hard palate
Bony structure in the anterior or front portion of the mouth formed by parts of the palatine and maxillary bones
Bile
Contains significant quantities of cholesterol and substances (bile salts) that act as detergents to mechanically break up, or emulsify, fats; because fats form large globules, they must be broken down, or emulsified, into smaller particles to increase the surface area to aid digestion; in addition to emulsification of fats, bile that is eliminated from the body in the feces serves as a mechanism for excreting cholesterol from the body; both emulsification of fats and elimination of cholesterol from the body are primary functions of bile
Common Hepatic ducts
Carry bile from each lobe of the liver toward the gallbladder; obstruction of the common hepatic duct also leads to jaundice
Chondrocytes
Cartilage cells; located in lacunae; lacunae are suspended in the cartilage matrix because there are no blood vessels; nutrients must diffuse through the matrix to reach the cells; because of the lack of blood cells, cartilage rebuilds itself very slowly after an injury
Epiglottis
Cartilage; partially covers the opening of the larynx; closes off the larynx during swallowing and preventing food and liquids from entering the trachea
Vertical column/spine
Composed of cervical, thoracic and lumbar regions; also have 2 additional bones-modified vertebrae-which are found at the inferior end of the vertebral column called the sacrum and coccyx
Fibrocartilage
Strongest and most durable type of cartilage; matrix is rigid and filled with a dense packing of strong collagen fibers; serve as shock absorbers between adjacent vertebrae and in the knee joint
Periodontitis
Generalized and serious type of inflammation and infection of this membrane and surrounding bone; often a complication of untreated gingivitis; as the infection worsens, it will cause loss of both periodontal membrane and bone, resulting in loosening and eventually complete loss of teeth; leading cause of tooth loss among adults
Mucosa
Delicate layer of simple columnar epithelium structured for absorption and secretion; the mucosa of the esophagus is composed of tough and abrasion-resistant stratified epithelium; the mucus produced by either type of epithelium coats the lining of the alimentary canal
Nucleolus
Dense region of the nucleus where ribosomes are made; the ribosome subunits then migrate through the nuclear envelope into the cytoplasm of the cell to form ribosomes, which produce proteins
Iron deficiency anemia
Without adequate iron in the diet, the body cannot manufacture enough hemoglobin; iron is a critical component of the hemoglobin molecule; a worldwide medical problem
Salts
a class of ionic compounds that can be formed during the reaction of an acid and a base; when a strong acid and a strong base mix, excess H+ ions may combine with the excess OH ions to form water so they might neutralize each other
Cytoskeleton
"Cell skeleton"; provides support and movement; the various organelles are held by the fibers and molecular motors of the cytoskeleton; when cells or organelles move, it's parts of the cytoskeleton that are pulling or pushing membranes and organelles
Dorsiflexion
The dorsum, or top of the foot is elevated with the toes pointing upward
interstitial fluid (IF)
Tissue fluid which bathes every cell in the body
Superior
Meaning "towards the head"; also means "upper" or "above"
Hamstring muscles
3 of them: semimebraneous, semitendinosis, and biceps femoris; when acting together, they serve as powerful flexors of the leg; they originate on the ischeum and insert on the tibia or fibula
platelet/thrombocyte
3rd main type of formed element, plays an essential part in blood clotting or coagulation; a clot plugs up torn or cut vessels and stops bleeding that otherwise might prove fatal; thrombocytes comes from thrombus which means "clot"; much smaller than RBCs; tiny cell fragments that have broken away from a much larger precursor cell; each tiny platelet is filled with chemicals necessary for triggering the formation of a blood clot
wrist and hand
8 carpal/wrist bones; 5 metacarpal bones that form the support structure for the palm of the hand and 14 phalanges/finger bones; the presence of many small bones in the hand and wrist and the many movable joints between them makes the human hand highly maneuverable
simple goiter
A painless enlargement of the thyroid gland caused by low dietary intake of iodine; the gland enlarges to compensate for the lack of iodine in the diet necessary for the synthesis of thyroid hormones; condition was once common in areas of the U.S. where the iodine content of salt and water is inadequate; the use of iodized salt has dramatically reduced the incidence
Pharynx (throat)
About 12.5 cm (5 inches) long and can be divided in 3 - the nasopharynx is the uppermost part of the tube just behind the nasal cavities, the oropharynx is the portion behind the mouth, and the laryngopharynx is the last/lower segment; air and food pass through the pharynx on their way to the lungs and stomach, respectively; air enters the pharynx from the 2 nasal cavities or the oral cavity and leaves it by way of the larynx; food enters the pharynx from the mouth and leaves it by way of the esophagus
Neoplasm
An abnormal mass of proliferating cells develops if the body loses its ability to control the cell life cycle; could be benign or malignant
Developmental processes
Changes and functions occurring during the early years; improves efficiency of functions
Clavicle
Collar bone
BioChemistry
Field of science devoted to studying the chemical aspects of life
Weak acid
Dissociates very little and therefore produces few excess H+ ions in solution; pH value just below 7
Complementary base pairing
Each step in the DNA ladder consists of a pair of bases; only 2 combos of bases occur and the same 2 bases always pair off with each other in a DNA molecule; Adenine always binds to thymine, and cytosine always binds to guanine
Alveoli
Extremely tiny, thin-walled sacs that are the ends of a tube with many branches; a network of capillaries fits like a hairnet around each microscopic alveolus; the function of alveoli as well as the entire respiratory system is to distribute air close enough to blood for a gas exchange to take place between air and blood
Essential organs
Gonads
Hypotonic
Having a lower concentration of solute than another solution
hypertension (HTN)
High blood pressure; if it becomes too high, it can cause the rupture of 1 or more blood vessels, i.e. in the brain, like what happens in a stroke; chronic HTN can also increase the heart's load causing abnormal thickening of the myocardium-and may even lead to heart failure
Tongue
Makes up the floor of the mouth along with its muscles; made of skeletal muscle covered with mucous membrane; anchored to bones in the skull and to the hyoid bone in the neck
Disaccharide
Molecule made of 2 saccharide units (double sugar); examples are lactose and sucrose; after these are eaten, the body digests them to form monosaccharides that can be used as cellular fuel
Abduction
Moving a part away from the midline of the body, such as moving your arm out to the side
antidiuretic hormone (ADH)
One of the hormones that is made in the hypothalamus; affects the volume of urine excreted
latissimus dorsi
Originates from structures over the lower back; inserts on the humerus and is an extensor of the arm
external oblique
Outermost layer of the muscle in the anterolateral (side) abdominal wall
Active transport process
Requires the expenditure of energy by the cell, energy required for active transport is retrieved by ATP; cellular energy is required to move substances from a low concentration to a higher concentration; uphill ("up a concentration gradient", from lower to higher concentration) movement of a substance through a living cell membrane
Bursae
Small fluid filled sacs; lie between some tendons and the bones beneath them; lined with synovial membrane
tunica media
Smooth muscle tissue is found in the middle layer of arteries and veins; means "middle coat"; muscle layer is much thicker in arteries than it is in veins because the thicker muscle layer in the artery wall is able to resist great pressures generated by ventricular systole; in arteries, the tunica media plays a critical role in maintaining blood pressure and controlling blood distribution; this is a smooth muscle, so it is controlled by the ANS; the tunica media also sometimes includes a thin layer of elastic fibrous tissue; smooth muscle cells along the wall of arterioles are sometimes called precapillary sphincters; they encircle the arteriole walls and by contracting or relaxing, they regulate how much blood will flow into a capillary bed
Hemodynamics
The set of processes that influence the flow of blood
Paracrine agents
locally acting chemicals that affect cells other than those that secrete them, including PGs, leukotrienes and thromboxane; paracrine literally means "secrete beside" - an apt description for a regulatory agent released right next to its target cell
Dermatomes
Skin surface areas that are supplied by a single spinal nerve
interstitial cells
Small endocrine cells lying near the septa that separate the lobules; secrete the male sex hormone testosterone
Trabeculae
The beams that form the lattice of spongy bone
Hematopoietic tissue
The bloodlike connective tissue found in the red marrow cavities of bones and in organs such as the spleen, tonsils, and lymph nodes; responsible for formation of blood cells and lymphatic system cells important in our defense against disease
Agglutination
Antibodies' reactions with the antigens to form clumps; they cause their targeted antigens to stick together which is a mechanism often used by the immune system to fight infection
Smooth ER
Areas of the ER are so full of molecules that ribosomes don't have room into which they can pass their proteins so they don't attach; this ER is smooth because of the absence of ribosomes; fats, carbohydrates, and proteins that make up cellular membranes are manufactured in smooth ER; the smooth ER then makes a new membrane for the cell
postganglionic neuron
Conduct impulses from a ganglion to cardiac muscle, smooth muscle, or glandular epithelial tissue
pectoralis major
Fan-shaped; attaches the upper extremity to the thorax; covers the upper chest; inserts on the humerus and is a flexor
Tonsils
Masses of lymphoid tissue are embedded in the mucous membrane of the pharynx; linguil tonsils and palatine tonsils are located in the oropharynx and the pharyngeal tonsils (adenoids) are located in the nasopharynx; form a ring of lymphoid tissue in the throat that provides immune protection at a critical boundary with the external environment; although the tonsils usually protect us, they can also become inflamed and infected (tonsillitis); swelling of the pharyngeal tonsils caused y infections may make it difficult or impossible for air to travel from the nose into the throat; in these cases, the person is forced to breathe through the mouth
Kidneys
Protected a bit by the lower rib cage and are located under the muscles of the back and behind the parietal perineum - the membrane that lines the abdominal cavity; because of its location, a surgeon can operate on a kidney from behind without cutting through the parietal perineum which will then reduce the potential for spread of infection throughout the abdominal cavity; a heavy cushion of fat - the renal fat pad - normally encases each cavity and helps hold it in place; normally a little more than 20% of the total blood pumped by the heart each minute enters the kidneys; this is understandable because one of main functions of the kidney is to remove waste products from the blood; maintenance of a high rate of blood flow and normal BP in the kidneys is essential to form urine; kidneys resemble Lima beans in shape, that is, roughly oval with a medial indentation
Peristalsis
Rhythmic, wavelike contraction of the gut wall caused by alternating a wavelike contraction along the circular muscle layer in the muscularis; this type of sequenced contraction squeezes and pushes ingested food material forward through the digestive tube's internal pathway - like squeezing toothpaste out of the tube
Pericardium
Serous membrane that surrounds the heart; surrounded by a fibrous sac lined with a thin slippery membrane that doubles back on itself to form a lubricating, fluid-filled pocket around the heart
Parathyroid glands
Small lumps of glandular epithelium; usually 4 of them and they're found on the posterior surfaces of the thyroid gland; they secrete parathyroid hormone (PTH)
Liver
So large that it fills the entire upper right section of the abdominal cavity and even extends partway into the left side; classified as an exocrine gland because it secretes a substance called bile into ducts; largest gland in the body; removes yellowish bile pigments formed by the breakdown of hemoglobin from old RBCs and puts them into the bile for elimination from the body; continuously secretes bile; if there is no chyme in the duodenum, then circular sphincter muscles within the duodenal papillae remain closed-and the bile backs up the common bile duct into the cystic duct that leads to the gallbladder
Surfactant
Substance that covers the surface of the respiratory membrane inside each alveolus; helps reduce surface tension or "stickiness" of the watery mucus lining the alveoli-keeping the alveoli from collapsing as air moves in and out during respiration
compounds
Substances whose molecules have more than one element in them; chemical formula is used in order to describe which atoms are present in a compound
Red blood cell (RBC)
Surrounded by a tough and flexible plasma membrane, is "caved in" on both sides so that each one has a thin center and thicker edges; this biconcave disk shape provides a large surface area for moving dissolved blood gases (oxygen and carbon dioxide) and other solutes quickly in or out of the blood cell; it also helps the RBCs from spinning as they flow through the bloodstream; mature RBCs have no nucleus or cytoplasmic organelles; because of this, they are unable to reproduce themselves or replace lost or damaged cellular components; the result is a relatively short life span of about 80 to 120 days; called erythrocytes because they are filled with hemoglobin; during its short life span, each RBC travels around the entire cardiovascular system more than 100,000 times; it is the flexible plasma membrane that permits each cell to "deform" and undergo drastic changes in shape as it repeatedly passes through capillaries whose lumen is smaller than the RBC's diameter; because of the large numbers of RBCs and their unique bioconcave shape, the total surface area available for them to perform their biological functions is enormous
vas deferens (ductus deferens)
The tube that permits sperm to exit from the epididymis and pass from the scrotal sac upward into the abdominal cavity; each vas deferens is a thick, smooth, very muscular, and movable tube that can easily be felt or "palpated" through the thin skin of the scrotal wall; it passes through the inguinal canal into the abdominal cavity as part of the spermatic cord, a connective tissue sheath that also encloses blood vessels and nerves
lumbar puncture (spinal tap)
The withdrawal of some CSF from the subarachnoid space in the lumbar region of the spinal cord; the physician inserts a needle just above or below the fourth lumbar vertebra which can be easily located because it lies along the iliac crest; often performed when CSF is needed for analysis or when it is necessary to reduce pressure caused by swelling of the brain or spinal cord after injury/disease; normal CSF is slightly yellowish and clear in appearance
Cerebral cortex
Thin layer of gray matter; made up neuron dendrites and cell bodies; forms the surface of the cerebrum; important to understand that specific areas of the cortex have specific functions; this localization of function explains the specific symptoms associated with an injury to localized areas of the cerebral cortex after a stroke or traumatic injury to the head; emotional brain; emotions can widespread changes in the automatic functions of our bodies
Crenation
This happens when a cell shrinks and shrivels; can result in cell death if severe; called crenation because under a microscope, the cells appear to have a crenated (scalloped) border
Blood supply to the heart muscle
To sustain life, the heart must pump blood throughout the body on a regular and ongoing basis; as a result the myocardium requires a constant supply of blood containing nutrients and oxygen to function effectively
tendon sheaths
Tube-shaped structures; Enclose some tendons; they facilitate body movement like the bursa because they are also lined with synovial membrane and are moistened with synovial fluid
Allergy
Used to describe hypersensitivity of the immune system to relatively harmless environmental antigens; 1/6 Americans has a genetic predisposition to an allergy; immediate allergic responses involve antigen-antibody reactions that trigger the release of histamine, kinins, and other inflammatory substances; these responses usually cause symptoms such as a runny nose, conjunctivitis, and hives; in some cases, these substances may cause constriction of airways, relaxation of blood vessels, and irregular heart rhythms that can lead to anaphylactic shock; delayed allergic responses involve cell-mediated immunity
Urogenital tract/reproductive tract
Used to describe the dual repoorductive and urinary functions of the urethra
Experimental controls
Used to ensure that the test situation is not affecting the results; i.e. when testing a new medicine, the test group gets the drug and the control group gets a harmless substitute
Sphincter
Valvelike rings of muscle tissue that often surround tubular structures or body openings; in the GI tract, they normally act to keep ingested material moving in one direction down the tube; partial digestion of proteins occurs after chyme is held in the stomach for some time by the pyloric sphincter muscle; the smooth muscle fibers of the sphincter stay contracted most of the time and thereby close off the opening of the pylorus into the small intestine; after food has been mixed in the stomach and protein digestion gets underway, chyme begins its passage through the pyloric sphincter into the 1st part of the small intestine
diabetes mellitus (DM)
a condition marked by the underproduction or lack of the hormone insulin; screening tests rely on the fact that the blood glucose level is high; most screening is done with a simple test on a drop of blood or testing urine; people with a high glucose level are thought to have DM; exercise physiologists have found that exercise/aerobic training increases the number of insulin receptors in target cells and the insulin affinity (attraction) of the receptors; this allows a smaller amount of insulin to have a greater effect than it would have had; all types of DM benefit from properly planned exercise therapy
Cardiopulmonary resuscitation (CPR)
because of this placement, it can be compressed or squeezed by application of pressure to the lower portion of the body of the sternum using the heel of the hand; rhythmic compression of the heart in this way can maintain blood flow in cases of cardiac arrest, and if combined with effective artificial respiration, the resulting procedure can be lifesaving; the exact procedures for CPR change frequently as new research data becomes available, so it is important that individuals certified in CPR become decertified on a regular basic
tunica externa/tunica adventitia
outer layer is made of connective tissue fibers which reinforce the wall of the blood vessel so that it will not burst under pressure; the connective fibers also connect to the extracellular matrix of surrounding tissues to help hold the vessel in place; the word tunica means "coat" and externa means "outside"
neurohypophysis
posterior pituitary gland; releases 2 hormones: antidiuretic hormone and oxytocin; both hormones are produced in cell bodies that are located in the hypothalamus but are released from the ends of axons that are located in the posterior pituitary gland
plantar flexion
the bottom of the foot is directed downward so that you are in effect standing on your toes
Pneumothorax
the presence of air in the intrapleural space on one side of the chest; the additional air increases the pressure on the lung on that side and causes it to collapse; while collapsed, the lung does not function in breathing
Absorption
Movement through the GI mucosa into the internal environment; once the digestive processes have altered the physical and chemical composition of ingested food, the resulting nutrients are ready for absorption
Axon
Processes that carry impulses away from the neuron cell bodies
Adrenal cortex
The outer part of an adrenal gland and is made up of glandular epithelium; has 3 different zones; outer zone that secretes mineralocorticoids (MCs), middle zone that secretes glucocorticoids (GCs) and innermost zone which secretes small amounts of sex hormones
blood viscosity
thickness of blood; if blood becomes less viscous than normal, BP decreases, i.e. if a person suffers a hemorrhage, fluid moves into the blood from the interstitial fluid which dilutes the blood and decreases its viscosity, and the BP falls; after hemorrhage, the transfusion of whole blood/plasma is preferable to an infusion of saline solution because the saline solution is not viscous so it can't keep the BP at a normal level
skeletal system
Can provide this support only when the composition of the bone is strong enough to hold the weight yet flexible enough to withstand twisting forces; protects the soft tissues that are located inside of bony cavities
Buffers
Chemicals in the blood that maintain pH; they do this by forming a chemical system that neutralizes acids and bases as they are added to a solution
Anterior
Means "front" or "in front of"
Acromegaly
Occurs when GH hypersecretion occurs after adolescence; characteristics include enlargement of the bones, hands, feet, jaws and face; facial appearance typical of acromegaly results from the combination of bone and soft tissue overgrowth; prominent forehead and large nose are characteristic; the skin also has large, widened pores and the mandible grows so the lower jaw protrudes and separation of the lower teeth commonly occurs
Neurilemma
Outer wrapped layer of a Schwann cell; plays an essential part in the regeneration of cut and injured axons so it is clinically significant that axons in the brain and spinal cord don't have neurilemma, therefore the potential for regeneration in the brain and spoon all cord is far less than it is in the PNS
Chyme
Partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach; continuation of the mechanical digestive process that begins in the mouth; gastric juice contains hydrochloride acid that unfolds proteins by breaking apart hydrogen bonds; then, enzymes in the gastric juice break apart the peptide bonds within protein molecules - all part of chemicals. Digestion
Urinary system
Performs the functions of producing and excreting urine from the body; these functions are so essential for the maintenance of homeostasis and healthy survival; the constancy of body fluid volumes and the concentration of many important chemicals depend on normal urinary system function; unless the urinary system operates properly, the normal composition of blood cannot be maintained for long, and there will be serious consequences; composed of 2 kidneys, 2 ureters, a bladder, and an urethra
Spinal cord reflexes
Reflexes that result from conduction over arcs whose centers lie in the spinal cord; 2 common kinds are withdrawal and jerk reflexes; an example of a withdrawal reflex is pulling one's hand away from a hot surface; the knee jerk is an example of a jerk reflex;
Regulation
Regulation of activities such as motility and secretion is required to coordinate the various mechanisms of digestion
anticoagulant therapy
The anticoagulant Coumadin (warfarin sodium) acts by inhibiting the synthesis of prothrombin and other vitamin-K dependent clotting factors; by doing so, Coumadin decreases the ability of blood to clot and is effective in preventing repeat thromboses after a heart attack or the formation of clots after surgical replacement of heart valves; Heparin can also be used to prevent excessive blood clotting; it inhibits the conversion of prothrombin to thrombin, thus preventing formation of a thrombus; the most widely used anticoagulant is low-dose (81 mg) aspirin; this readily available drug inhibits the formation of tiny platelet plugs and the subsequent formation of emboli, which may cause blockage of small blood vessels in the brain and lead to a stroke
Depolarization
The electrical activity that triggers contraction of the heart muscle; in a normal ECG, the seas all P wave occurs with a depolarization of the atria; the QRS complex occurs as a result of the ventricles, and the T wave results from electrical activity generated by depolarization of the ventricles; the reason atrial depolarization is not seen on the ECG because the deflection is very small and is hidden by the large QRS complex that occurs at the same time
Hemoglobin
The hemoglobin molecules that fill the millions of RBCs are critical in the transport and exchange of oxygen and carbon dioxide between the blood and the body's cells; they also play a key role in maintenance of acid-base balance in the body; quaternary protein made up of 4 folded polypeptide chains, 2 alpha chains and 2 beta chains; there is a chemical structure called a heme group embedded within each folded chain;
Synaptic cleft
The space between a synaptic knob and the plasma membrane of a postsynaptic neuron; incredibly narrow space - about two millionths of a cm in width; filled with extracellular matrix that holds the synaptic structure in place
Autonomic/visceral effectors
The tissues to which autonomic neurons conduct impulses; cardiac muscle that makes up the wall of the heart, smooth muscle that partially makes up the walls of blood vessels and other hollow internal organs, and glandular epithelial tissue that makes up the secreting part of a gland; conduction paths to visceral and somatic effectors from the CNS differ somewhat; autonomic paths to visceral effectors consist of two-neuron relays; impulses travel over preganglionic neurons from the spinal cord or brainstem to autonomic ganglia; they're relayed across synapses to postganglionic neurons which then conduct the impulses from the ganglia to visceral effectors; a single somatic motor neuron conducts impulses all the way from the spinal cord or brainstem to somatic effectors with no intervening synapses
Cellular respiration
The use of oxygen by cells in the process of metabolism
positive feedback
Usually uncommon; amplify change rather than reverse it; such amplifications can threaten homeostasis but in some situations it can help the body maintain its stability, i.e. during labor, muscle contractions that push the baby through the birth canal become stronger because of a positive feedback mechanism that regulates secretion of the hormone oxytocin
pleurisy
Very painful pathological condition characterized by inflammation of the serous membranes (pleura) that line the chest cavity and cover the lungs; pain is caused by irritation and friction in the inflamed pleura as the lung rubs against the wall of the chest cavity; in severe cases, the inflamed surfaces of the pleura form together and permanent damage may develop
Hyperventilation
Very rapid and deep respirations; sometimes results from a conscious voluntary effort preceding exertion or from psychological factors-"hysterical hyperventilation"
Eosinophils
Weak phagocytes; most important function involves protection against infections caused by certain parasites and parasitic worms; also involved in regulating allergic reactions, including asthma
strong acid
an acid that is completely (or almost completely) ionized in aqueous solution; indicated by very low pH - far below pH7
Circumduction
moves a part so that its distal end moves in a circle, i.e. when a pitcher winds up to throw a ball, he/she circumducts his/her arm
peritonitis
Inflammation of the serous membranes in the abdominal cavity; can be a serious complication of an infected appendix
transversus abdominis
Innermost layer of the muscle in the anterolateral abdominal wall
Atrioventricular valves (AV)
2 valves that separate the atrial chambers above from the ventricles below; prevent backflow of blood into the atria when the muscles contract
Ovum
Egg (from the female parent)
Polyuria
Excessive urination
Myoglobin
A red, oxygen-storing pigment similar to hemoglobin; during rest, oxygen carried to muscles by hemoglobin in the blood is taken up by myoglobin within muscle fibers; as oxygen is used up quickly during muscle contractions, oxygen from myoglobin adds to the oxygen from hemoglobin - thereby allowing maximum "recharging" of energy-containing ATP molecules
Motor unit
A single motor neuron, with the muscle fibers it innervates
Monosaccharide
Basic unit of carbohydrate; glucose (dextrose) is important since cells use it as their primary source of energy
Pulmonary gas exchange
Blood pumped from the R ventricle of the heart enters the pulmonary artery and eventually enters the lungs; it then flows through the thousands of tiny pulmonary capillaries that are in close proximity to the air-filled alveoli
Blood transportation of gases
Blood transports the respiratory gases either in a dissolved state or combined with other chemicals; immediately on entering the blood, both oxygen and carbon dioxide dissolve in the plasma, but because fluids can hold only small amounts of gas in solution, most of the oxygen and carbon dioxide rapidly form a chemical union with hemoglobin or water; once gas molecules are bound to another molecule, their plasma concentration (partial pressure) decreases and more gas can diffuse into the plasma; in this way, comparatively large volumes of the gases can be transported
Uvula
Cone-shaped structure hanging down from the soft palate; the uvula and the soft palate prevent any food and liquid from entering the nasal cavities above the mouth and also assist in speech and swallowing
Blood volume
Direct cause of BP is the volume of blood in the vessels; the larger the volume of blood is in the arteries, i.e. the more pressure the blood exerts on the walls of the arteries, or the higher the arterial BP will be; the less blood there is in the arteries, the lower the BP tends to be; hemorrhage is a pronounced loss of blood and this decrease in the volume of blood causes the BP to drop; the major sign of hemorrhage is a rapidly falling BP; diuretics (drugs that promote water loss by increasing urine output) are often used to treat HTN; as water is lost from the body, blood volume decreases so the BP decreases to a lower level; the volume of blood in the arteries is determined by how much blood the heart pumps into the arteries and how much blood the arterioles drain out of them; the diameter of the arterioles plays an important role in determining how much blood rains out of arteries into arterioles
Prime mover
Of all the muscles contracting simultaneously, this one is mainly responsible for producing a particular movement
Repolarization
The immediate recovery of the depolarized section of the membrane, however, the depolarization has already stimulated the NA+ channels in the next section of the membrane to open
Neurophysiology
The physiology of brains and nerves
signal transduction
The process by which a signal on a cell's surface is converted into a specific cellular response.
Translation
The process of "translating" the genetic code in the mRNA transcript to synthesize a protein; occurs within ribosomes, which attach around the mRNA strands in the cytoplasm; the ribosomes move along the mRNA transcript and "read" the info encoded there to direct the choice and sequencing of the appropriate chemical building blocks called amino acids; the sub-units of a ribosome attach at the beginning of the mRNA molecule; the ribosome then moves down the mRNA strand as amino acids are assembled into their proper sequence
Involution
The thymus tissue is then gradually replaced by fat and connective tissue
Ureters
The tubes that carry urine from the kidneys to the bladder.; mucous membranes featuring easily stretchable transitional epithelium line both ureters and each renal pelvis; has a thick muscular wall; contractions of the muscular coat produces peristaltic-type movements that assist in moving urine down the ureters into the bladder; the lining membrane of the ureters is richly supplied with sensory nerve endings
Thyroid hormone
Two similar hormones triiodothyronine (T3) and thyroxine (T4); T4 is the more abundant; T3 is the more potent and is considered by physiologists to be the principal thyroid hormone; one molecule of T4 contains 4 atoms of iodine and one molecule of T3 contains 3 atoms of iodine; for thyroid hormones to be produced in adequate amounts, the diet must contain sufficient iodine; most endocrine glands do not store their hormones but instead secrete them directly into the blood as they are produced; the thyroid gland is different in that it stores considerable amounts of the thyroid hormones in the form of molecules suspended in fluid as a colloid; the colloid material is stored in the follicles of the gland, and when the thyroid hormones are needed, they are released from the colloid and secreted into the blood; T3 and T4 are small, nonsteroid hormones that are able to enter their target cell to find their receptors; this is an exception to the general model of nonsteroid action requiring an internal second messenger; T3 and T4 influence every one of the trillions of cells in our bodies; they make them speed up their release of energy from nutrients; in other words, these thyroid hormones stimulate cellular metabolism; this has far-reaching effects; because all body functions depend on a normal supply of energy, they all depend on normal thyroid secretion; even normal mental and physical growth and development depend on normal thyroid functioning
Acetylcholine (ACh)
Type of neurotransmitter operating in each NMJ; signal chemicals are released by the motor neuron in response to a nervous impulse; the released ACh moves across the NMJ and triggers events within the muscle fiber that results in contraction of the shortening of the muscle fiber
Organism
Used to denote a living thing; implies organization
efferent lymphatic vessels
Vessels leaving the lymph node
Heart sounds
When a stethoscope is placed on the anterior chest wall, 2 distinct sounds are heard that are rhythmical and repetitive that are described as lub dup; the 1st sound (lub) is caused by the vibration and abrupt closure of the AV valves as the ventricles contract; closure of the AV valves prevent blood from rushing back up into the atria during contraction of the ventricles; the 1st sound is of longer duration and lower pitch than the 2nd; the pause between the 1st sound and the dup (2nd sound) is shorter than that after the 2nd sound and the lub dup of the next systole; the 2nd heart sound is caused by the closing of both SL valves when the ventricles undergo diastole (relax); physicians can use a stethoscope to detect many types of heart valve abnormalities as alterations of the normal lub dup pattern
articular cartilage
a thin layer of cartilage covering each epiphysis; functions like a small rubber cushion would if it were placed over the ends of bones where they form a joint
Bicarbonate(HCO3-)
about 70% of the total CO2 transported in the blood; when CO2 dissolves in water (as in blood plasma), some of the CO2 molecules associate with water (H2O) to form carbonic acid (H2CO3); once formed, some of the H2CO3 molecules dissociate to form hydrogen (H+) and bicarbonate (HCO3-) ions; the speed of this process is quite slow when it happens in the plasma, but the rate of reaction increases dramatically within RBCs because of the presence of an enzyme called carbonic anhydrase (CA); the reaction is reversible; if bicarbonate is being formed, CO2 molecules entering into plasma can continually be removed from the blood and transported to the lungs; and, when the the process is reversed in the lungs, CO2 can be released to enter the alveolar air and then be exhaled
Respiratory arrest
failure to resume breathing after a prolonged period of apnea
cholinergic fibers
release acetylcholine - they are the sympathetic preganglionic axon, the parasympathetic preganglionic axon, and the parasympathetic postganglionic axon
eccentric contraction
tension during muscle lengthening
HDL (high density lipoprotein)
"good cholesterol" that carries cholesterol back to the liver, where it is removed from the blood
Rough ER
1 of the 2 types of ER; gets its name from the many ribosomes that are attached to its outer surface, giving it a rough texture like sandpaper; as ribosomes make their proteins, they may attach to the rough ER and insert the protein into the ER's interior; the ER then begins folding the new proteins and transports them to areas in which chemical processing takes place
cranial nerves
12 pairs of cranial nerves are attached to the undersurface of the brain; the nerves are attached to the brainstem and diencephalon; their fibers conduct impulses between the brain and structures in the head and neck and in the thoracic and abdominal cavities, i.e. the 2nd cranial nerve (optic nerve) conducts impulses from the eye to the brain, where these impulses produce vision; the 3rd cranial nerve (oculomotor nerve) conducts impulses from the brain to muscles in the eye, where they cause contractions that move the eye; the 10th cranial nerve (vagus nerve) conducts impulses between the medulla oblongata and structures in the neck and thoracic and abdominal cavities
Prophase
1st stage of mitosis; the chromatin becomes "organized"; chromosomes in the nucleus have formed 2 strands called chromatids; the 2 chromatids are held together by a beadlike structure called a centromere; in the cytoplasm the centrioles are moving away from each other as a network of tubules (spindle fibers) forms between them; the spindle fibers serve as "guidewires" and help the chromosomes move toward opposite ends of the cell later on in mitosis
Lacrimal sacs
2 ducts that also drain into the nasal cavity; they collect tears from the corner of each eyelid and drain them into the nasal cavity
Phospolipids
2 layers of of phosphate-containing fat molecules
Ventricles
2 lower chambers of the heart; sometimes referred to as discharging chambers of the heart; R and L ventricular chambers; interventricular septum separates the ventricles
Ovaries
2 ovaries are a woman's primary sex organs; each ovary contains ovarian follicles and the corpus luteum
atria (atrium)
2 upper chambers of the heart; smaller than the ventricles, and their walls are thinner and less muscular; often called receiving chambers because blood enters the heart through veins that open into these upper cavities; eventually, blood I'd jumped from the heart into arteries that exit from the ventricles; R and L atrial chambers; septum between the atrial chambers is the interatrial septum; although the atria contract as an unit, followed by the ventricles below, the R and L sides of the heart act as separate pumps
R and L coronary arteries
2 vessels that allow the blood to flow into the heart muscle; coronary arteries are the aorta's first branches; the openings into these small vessels behind the flaps of the aortic SL valve; during ventricular systole, the the myocardium is contracting and putting pressure on the coronary arteries so little blood can enter them; however, during ventricular diastole, blood that backs up behind the aortic SL valve can flow easily into the coronary arteries; in both coronary thrombosis and embolism, a blood clot occludes or plugs up some part of a coronary artery; blood cannot pass through the occluded vessel and so cannot reach the heart muscle cells it normally supplies
Biological filtration
A process in which cells (phagocytes) alter the contents of the filtered fluid; biological filtration of bacteria and other abnormal cells by phagocytosis prevents local infections from spreading
Cerebellum
2nd largest part of the brain; lies under the occipital lobe of the cerebrum; in the cerebrum, folded gray matter composes the thin outer layer and forms a large surface area of nervous connections that allow for a huge amount of information processing; white matter tracts form most of the interior; the tracts branch in a treelike pattern called the arbor vitae which literally means living tree; most obvious functions are to produce smooth coordinated movements, maintain equilibrium, and sustain normal procedures; recent brain imaging studies show that the cerebellum may assist the cerebrum and other parts of the brain, perhaps serving as an overall coordinator for the brain
salivary glands
3 pairs of salivary glands - parotid, sublingual, and submandibular-secrete most of the saliva (about 1 liter) produced each day in the adult; located outside of the digestive tube itself and must convey their exocrine secretions by way of ducts into the tract; some salivary secretions are said to be serous in nature if they are thin, watery, and free of mucus; serous-type saliva, produced by serous-type secretory cells, contains the digestive enzyme amylase; this enzyme begins the chemical digestion of carbohydrates; another type of saliva is thick and rich in mucus but contains no enzymes; mucous-type saliva, which is thick and slippery, is produced by mucous-type secretory cells; this type of saliva serves the important function of lubricating food during mastication, thus allowing it to pass with less friction through the esophagus and into the stomach; some saliva is a mixture of both serous-and mucous-type secretions
Myosin
A protein that forms thick myofilaments; each shaftlike molecule has a "head" that sticks out toward the actin molecules
Actin
A protein that forms thin myofilaments; when at rest, the actin is blocked from connecting with the myosin heads by small proteins that are attached to the actin; during contraction, the blocking proteins release actin and the myosin heads connect to form crossbridges between the thick and thin filaments.
Centrosome
A region of cytoplasm near the nucleus of each cell; serves as the microtubule- organizing center of the cell, thus playing an important role in organizing and moving the structures within the cell; also plays a role in forming and organizing the cell's cytoskeleton, including some of a cell's outward extensions
Spinal nerves
31 pairs of nerves are attached to the spinal cord in the following order: 8 pairs are attached to the cervical segments, 12 pairs are attached to the thoracic segments, 5 pairs are attached to the lumbar segments, 5 pairs are attached to the sacral segments, and 1 pair is attached to the coccygeal segment; have no special names but a letter and a number identify each one, i.e. C1 indicates the pair of spinal nerves attached to the 1st segment of the cervical part of the spinal cord; when viewing the dissected cervical area of the spine to show the emerging spinal nerves in that area, once the spinal nerves exit from the spinal cord, they branch to form the many peripheral nerves of the trunk and limbs; sometimes, nerve fibers from several spinal nerves are reorganized to form a single peripheral nerve; they conduct impulses between the spinal cord and the parts of the body not supplied by cranial nerves; they contain sensory and motor fibers; they function to make possible sensations and movements; a disease or injury that prevents conduction by a spinal nerve thus result in a loss of feeling and a loss of movement in the part supplied by that nerve
sudden infant death syndrome (SIDS)
3rd ranking cause of infant death and accounts for about 1 in 9 of the nearly 30,000 infant deaths reported each year in the U.S.; sometimes called "crib death"; occurs most frequently in babies with no obvious medical problems who are younger than 3 months of age; exact cause of death can seldom be determined, even after extensive. testing and autopsy; occurs at a higher rate in African American and Native American babies; recent data suggests that certain precautions may reduce the incidence of SIDS; also important is the elimination of smoking during pregnancy and protecting infants from "secondhand" smoke; although the exact cause of SIDS remains unknown, genetic defects involving the structure and function of the respiratory system or unusual physiological responses to common flu or cold viruses may also play a role
Paranasal sinuses
4 of them - frontal, maxillary, sphenoidal, and ethmoidal-which drain in to the nasal cavities; lined with a mucous membrane that assists in the production of mucus for the respiratory tract; these hollow spaces also help lighten the skull bones and serve as resonant chambers that enhance the production of sound; because the mucosa that lines the sinuses is continuous with the mucosa that lines the nose, sinus infections (sinusitis) often develop from colds in which the nasal mucosa is inflamed; symptoms of sinusitis include pressure, pain, headache, and often external tenderness, swelling, and redness; in chronic cases, infection may spread to adjacent bone or into the cranial cavity inflaming meninges or brain tissue; treatment includes decongestants, analgesics, antibiotics and sometimes surgery to improve drainage
Fontanels
6 Soft spots on a newborn baby's skull; areas of fibrous membrane that have not yet fully ossified; allow some compression of the skull during birth without much risk of breaking the skull bones; may also be important in determining the position of the baby's head before delivery; the soft membranes allow additional bone to form around the margins of the skull bones, thus permitting early rapid growth of an infant's skull; eventually fuse to form sutures before a baby is 2 years old
Sella turcica
A "seat"; formed by two bony projections at the top of the sphenoid bone
Antibodies
A class of proteins that are normally present in the body; defining characteristic is the uniquely shaped concave regions called combining sites on its surface; another defining characteristic is the ability of an antibody molecule to combine with an antigen; all antigens are compounds whose molecules have small region on their surfaces that are uniquely shaped to fit into the combining sites of a specific antibody molecule as precisely as a key fits into a lock ; antigens are often protein molecules embedded in the surface membranes of threatening or diseased cells; another important function is promotion and enhancement of phagocytosis; certain antibody fractions help promote the attachment of phagocytic cells to the object they will engulf; as a result, the contact between the phagocytic cell and its victim is enhanced, and the object is more easily ingested; this process contributes to the efficiency of immune system phagocytic cells
Positive feedback loops
A feedback loop in which change in a system is amplified
Accessory organs of reproduction (female)
A series of ducts or modified duct structures that extend from near the ovaries to the exterior; additional sex glands, including the mammary glands, which have an important reproductive function function only in women; the external reproductive organs, or external genitals
Arteries
A series of large distribution vessels that pump arterial blood from the heart; largest artery in the blood is the aorta; arteries subdivide and blood flows into vessels that become progressively smaller arteries until finally it enters tiny arterioles that. control blood flow into microscopic exchange vessels called capillaries; in the capillary beds, the exchange of nutrients and respiratory gases occurs between the blood and tissue fluid around the cells; blood exists/drained from the capillary beds and then enters the small venules which join with other venules and increase in size, becoming veins; the largest veins, often called sinuses, are the superior vena cava and the inferior vena cava; arteries carry blood away from the heart and toward capillaries; veins carry blood toward the heart and away from capillaries, and capillaries carry blood from the tiny arterioles into tiny venules; the aorta carries blood out of the L ventricle of the heart and the venue cavae return blood to the R atrium after the blood has circulated through the body
Cholesterol
A steroid lipid (multiple ring structure) that performs several important functions in the body; combines with phospholipids in the cell membrane to help stabilize its bilateral structure; the body also uses cholesterol as a starting point in making hormones such as estrogen, testosterone, and cortisone (cortisol)
Mucus
A thick, slimy material secreted by the epithelial cells of most mucous membranes; keeps the membranes moist and soft
luteinizing hormone (LH)
Acts with FSH to perform several functions; it stimulates a follicle and ovum to complete their growth to maturity, it stimulates follicle cells to secrete estrogens and it causes ovulation (rupturing of the mature follicle with explosion of its ripe ovum); sometimes called the ovulating hormone; as it promotes luteinization, LH stimulates the corpus luteum to produce the hormone progesterone; the male pituitary gland also secretes LH; in males, LH stimulates interstitial cells in the testes to develop and secrete testosterone
external nares (nostrils)
Air enters the respiratory tract through the nostrils, flowing in the R and L nasal cavities which are lined by respiratory mucosa; a partition called the nasal septum separates these 2 cavities; the surface of the nasal cavities is moist from mucus and warm from blood flowing just under it; nerve endings responsible for the sense of smell (olfactory receptors) are also located in the nasal mucosa
Genome
All of the DNA in each cell of the body; all gene locations have been mapped in the human genome but efforts are still being made to read the different genetic codes at each location; work done as part of the Human Genome Project (HGP) which was started in 1990; many scientists are still working to try to fill in the details of the many genes and gene variants found in the human genome
epiphyseal plate
An area of cartilage that remains between the epiphyses and diaphysis as long as growth continues; growth stops once all the epiphyseal cartilage turns into bone; all that remains is an epiphyseal line that marks where the 2 ossification sites have fused together; physicians use this to determine whether or not a child will still grow
Ion
An electrically charged atom
RhoGAM
An immunoglobulin (antibody) serum should be provided to all Rh-negative mothers who carry an Rh-positive baby; the serum stops the mother's body from forming anti-Rh antibodies and prevents the possibility of harm to the next Rh-positive baby; a person with Rh-negative blood who receives a transfusion of Rh-positive blood will also develop anti-Rh antibodies and be at risk of an immune reaction if exposed to Rh-positive blood later
Yellow bone marrow
An inactive, fatty form of marrow found in the adult skeleton
Systems
An organization of varying numbers and kinds of organs that can work together to perform complex functions for the body
Section
Another term for cut
Peripheral resistance (PR)
Any force that acts against the flow of blood in a blood vessel, i.e. viscosity of blood which influences the ease with which blood flows through the blood vessel; another factor that affects PR is the tension in smooth muscles of the blood vessel wall, when the muscles are relaxed, resistance is low and BP is low which means that blood can flow easily down its pressure gradient and into the vessel; when vessel wall muscles are contracted, resistance increases and so does the BP so the pressure gradient is reduced and blood does not flow so easily into the vessel
Immunization
Artificial and is the deliberate exposure of the body to a potentially harmful agent
Blood-brain barrier (BBB)
Astrocyte branches form a 2- layer structure along with the walls of the blood vessels; it separates the blood tissue and nervous tissue to protect vital brain tissue from harmful chemicals that might be in the blood
Osteocytes
Mature bone cells that were formerly active bone-making osteoblasts cells that have now become dormant
Protein molecule
Complex 3-D molecule; positive-negative attractions between different atoms in the long amino acid strand cause it to coil on itself again and again to form its highly complex shape; folded proteins may combine with other folded proteins to form even larger, more complicated shapes
Neuroendocrinology
Complex interactions between the neurological and endocrinological systems that together regulate physiology
Rectum abdominus
Band-or strap-shaped muscle runs down the midline of the abdomen from the thorax to the pubis; protects the abdominal viscera; flexes the vertebral column
Sarcomere
Basic functional or contractile unit of skeletal muscle; submicroscopic structure consists of numerous thick and thin myofilaments arranged so that, when viewed under a microscope, dark and light stripes, or cross striations, are seen; the repeating units, or sarcomeres, are separated from each other called Z lines or Z disks; when in a relaxed state, the thick and thin myofilaments, which are lying parallel to each other, still overlap; contraction of the muscle causes the 2 types of myofilaments to slide toward each other and shorten the sarcomere and thus the entire muscle; when the muscle relaxes, the sarcomeres can return to resting length, and the filaments resume their resting positions
Reflex arc
Basic type of neuron pathway; allow impulse conduction in one direction; it is a two-neuron arc because it only consists of sensory neurons and motor neurons; 3-neuron arcs are the next simplest and they contain the 3 types of neurons: sensory, motor and interneurons; a 2-neuron reflex arc has only a sensory neuron and a motor neuron with one synapse between them
renal pelvis (of kidney)
Basinlike upper end of the ureter located inside the kidney (the tube that drains urine into the bladder)
Bending and straightening the forearm at the elbow joint
Biceps brachii is the prime mover during bending, and the brachialis is the synergist muscle; when the biceps brachii and the brachialis muscles bend the forearm, the triceps brachii relaxes; therefore, when the forearm bends, the triceps brachii is the antagonistic muscle; while the forearm straightens, these 3 muscles work together as a team; during straightening, the triceps brachii becomes the prime mover and the biceps brachii and the brachialis are the antagonistic muscles; this combined and coordinated activity is what makes our muscular movements smooth and graceful
Apex
Blunt point of the lower edge of the heart lies on the diaphragm, pointing toward the left; physicians and nurses often listen to the heart sounds by placing a stethoscope on the chest wall directly over the apex of the heart; sounds of the so-called apical beat are easily heard in this area (the space between the 5th and 6th ribs on a line even with the midpoint of the left clavicle)
Anatomical position
Body is in an erect or standing posture with the arms at the sides and palms turned forward; head also points forward as do the feet which are aligned at the toe and set slightly apart; reference position that gives meaning to the directional terms used to describe the parts and regions
Osteoblasts
Bone forming cells; when an osteoblast becomes "trapped" between lamellae of hard bone matrix, it stops forming bone and is called an osteocyte; osteocytes resume their bone-making activity when osteoclasts (or an injury) remove the surrounding bone; when a bone is mechanically stressed from pulling a muscle, the osteoblasts are stimulated to strengthen the bone at that location to resist the stress of pulling muscle; for this reason, dancers/athletes may have denser, stronger bones than less active people
Cytokines
Chemicals released from cells to act as direct agents of innate, nonspecific immunity; can also trigger or regulate many innate and adaptive immune responses; critical to the cell-to-cell combinations that is needed to coordinate the combined innate and adaptive actions that are unleashed during any immune response; some of the cytokines attract WBCs to the area
Thoracic cavity
Chest cavity
submandibular glands
Called mixed or compound salivary glands because they contain both serous (enzyme) and mucus-reducing secretory cells; located just below the mandibular angle, are irregular in form, and are about the size of a walnut; the submandibular ducts open into the mouth on either side of the lingual frenulum
Low blood pressure
Can be dangerous too; if arterial pressure falls low enough, then blood will not flow through (perfuse) the vital organs of the body; circulation of blood and thus life will cease; massive hemorrhage, which dramatically reduces BP, kills in this way
Electric activity of the heart
Cardia muscle fibers can contract rhythmically on their own but if the heart is to pump effectively, they must be coordinated by electrical signals; although the rate of cardiac muscle's rhythm is controlled by autonomic nerve signals, the heart has its own built-in conduction system for coordinating contractions during the cardiac cycle; all of the cardiac muscle fibers in each region of the heart are electrically linked together; intercalculated disks are connections that electrically join muscle fibers into a single unit that can conduct an impulse through the entire wall of a heart chamber without stopping; thus both atrial walls and ventricular walls will contract at about the same time because all of their fibers are electrically linked
Cerebral cortex control of respiration
Cerebral cortex can influence respiration by sending nerve signals that affect the function of the respiratory centers of the brainstem; an individual may voluntarily override the "automatic" brainstem rhythm of breathing and speed up and allow down the breathing rate-or greatly change the pattern of respiration during activities; this ability permits us to change respiratory patterns and even to hold our breath for short periods to accommodate activities such as speaking, eating, or swimming under water
Aplastic anemia
Characterized by a reduction in RBC numbers following destruction of the blood-forming elements in bone marrow; the cause is often related to exposure to certain toxic chemicals, high-dose irradiation (x-rays), certain drugs, and chemotherapy agents
Neurotransmitters
Chemicals by which neurons communicate; at trillions of synapses in the CNS, presynaptic neurons release neurotransmitters that assist, stimulate, or inhibit postsynaptic neurons; at least 30 compounds have been identified as neurotransmitters; specific neurotransmitters are localized in discrete groups of neurons and released in specific pathways;
veins and venules
Collect blood from capillaries and return it to the heart; the larger veins also serve as blood reservoirs because they carry blood under lower pressure (than arteries) and can expand to hold a larger volume of blood or constrict to hold a much smaller amount; external pressure can turn veins, which have one-way valves, into pumps that help return blood to the heart
Pinocytosis
Comes from Greek word meaning "drink"; incorporates fluids or dissolved substances into cells by trapping them in a pocket of plasma membrane that pinches off inside the cell
Phagocytosis
Comes from Greek word meaning "to eat"; this process permits a cell to to engulf and literally "eat" relatively large particles; certain white blood cells can use this to destroy invading bacteria and chunks of debris from tissue damage; during this process, the cytoskeleton extends the cell's plasma membrane to form a pocket around the particles to be moved into the cell and then encloses the material in a vesicle; the cytoskeleton's movements pull the vesicle deeper into the cell; once in the cytoplasm, the phagocytic vesicle fuses with a lysosomes containing digestive enzymes and the particles are broken apart
Coronary bypass surgery
Common treatment for those who suffer from severely restricted coronary artery blood flow; in this procedure, veins or arteries are "harvested" or removed from other areas of the body and are used to bypass partial blockages in coronary arteries
Proteoglycans
Commonly found in a tissue's matrix; these molecules can provide various functions such as linking among cells, absorbing shocks, regulation of tissue function, and lubrication
skeleton
Composed of 206 bones; Provides the internal framework of the body; skeletal muscles are attached to the bones and internal organs are found in the cavities surrounded by the bones and skeletal muscles
Polycythemia
Condition resulting from bone marrow producing an excess of RBCs; the blood in people who have this condition may contain so many RBCs that it may become too thick to flow properly, resulting in a stroke or heart attack
interneurons/central or connecting neurons
Conduct impulses from sensory neurons to motor neurons; also often connect with each other to form complex, central networks of nerve fibers; lie entirely within the gray matter of the brain or spinal cord
Stratified squamous epithelium
Consists of several layers of closely packed cells, an arrangement that makes this tissue adept at protection, i.e. this protects the body against invasion by microorganisms; most microbes can't work their way through a barrier of stratified squamous tissue like that which composes the skin and mucous membranes; one way of preventing infection is to take good care of your skin
Lower respiratory tract
Consists of the trachea, the bronchial tree, and the lungs; the symptoms of what is referred to as a "chest cold" are similar to pneumonia and involve the organs of the lower respiratory tract
Frontal muscle
Contraction of this muscle allows you to raise your eyebrows in surprise and furrow the skin of your forehead into a frown
Diaphragm
Does-shaped muscle separating the abdominal cavity from the thoracic cavity; flattens out when it contracts during inspiration; instead of protruding up into the chest cavity, as it does at rest, it moves down toward the abdominal cavity as it contracts; thus the contraction or flattening of the diaphragm makes the chest cavity longer from top to bottom; nerve impulses passing through the phrenic nerve stimulate the diaphragm to contract
Treatment of ulcers
Current statistics show that about 1 in 10 individuals in the U.S. will suffer from from either a gastric or duodenal ulcer in his/her lifetime; these craterlike lesions, which destroy areas of stomach or intestinal lining, cause gnawing/burning pain and may ultimately result in hemorrhage, perforation, scarring, and other serious medical complications; long-term use of NSAIDS can cause ulcers but we know that most result from infection with the H. Pylori bacterium; this is especially so if the infected individual has a genetic predisposition to ulcers; H. Pylori infection is diagnosed by biopsy, breath, or blood antibody tests; currently the standard antibiotic-based treatment used most frequently to both heal ulcers and prevent recurrences is called triple therapy; it is successful in 80-95% of cases and requires 3 medications be taken concurrently for 2 weeks; triple therapy combines bismuth subsalicylate (Pepto Bismol) with 2 antibiotics; the same types of antisecretory drugs used to reduce stomach acid in GERD are also used in ulcer therapy
Acrosome
Covers the sperm head; A cap like structure containing enzymes that enable the sperm to break down the covering of the ovum and permit entry if contact occurs
Parathyroid hormone (PTH)
Counterbalances the effects of calcitonin by decreasing calcium in the bone and thus increasing blood calcium; from the parathyroid glands
Cementum
Covered by the root and neck of each toot
Endocrinology
Covers endocrine hormones which affect every cell in the body
peritoneum
Covers most of the organs in the abdominal cavity
epithelial tissue
Covers the body and many of its parts; also lines various parts of the body; form continuous sheets that contain no blood vessels because they're packed close together with little or no intracellular material between them
Endurance training (aerobic training)
Doesn't usually result in hypertrophy; this type of exercise program increases a muscle's ability to sustain moderate exercise over a long period of time; aerobic activities such as running, bicycling, or other primarily isotonic movements increase the number of blood vessels in a muscle without significantly increasing its size; the increased blood flow allows a more efficient delivery of oxygen and glucose to muscle fibers during exercise; also causes an increase in the number of mitochondria in muscle fibers; this allows production of more ATP as a rapid energy source
Parasympathetic preganglionic neurons
Dendrites and cell bodies are located in the gray matter of the brainstem and the sacral segments of the spinal cord; also referred to as the craniosacral system; extend some distance before terminating in the parasympathetic ganglia located in the head and in the thoracic and abdominal cavities close to the visceral effectors that they control
Tissue of tendons and ligaments
Dense with strong, twisted fibers that give the matrix a thick, rope like quality
Oxygen debt
Describes the continued increased metabolism that must occur in a cell to remove excess lactic acid that accumulates during prolonged exercise; the depleted energy reserves are replaced; labored breathing after stopping exercise is required to "pay the debt" of oxygen required for the metabolic effort; technical name is post-exercise oxygen consumption (EPOC), a term that more accurately describes what happens after exercise; good example of homeostasis at work; the body returns the cells' energy and oxygen reserves to normal, resting levels
sphygmomanometer
Device often used to measure BP in both home and clinical care settings; a traditional one is an inverted tube of mercury (Hg) with a balloonlike air cuff attached via an air hose; the arm cuff is placed around the arm and a stethoscope sensor is placed over the a major artery to listen for the arterial pulse; a hand-operated pump fills the air cuff, increasing the air pressure and pushing the column of mercury higher; while listening through the stethoscope, the operator opens the air cuff's outlet valve and slowly reduces the air pressure around the limb; loud, tapping Korotkoff sounds begin when the cuff pressure measured by the mercury column equals the systolic pressure (often below 120 mm Hg); as the air pressure continues to decrease, the Korotkoff sounds continue with each pulse of BP, then eventually disappear; the pressure measurement at which the sounds disappear is equal to the diastolic pressure (often 70-80 mm Hg); BP is then expressed as systolic pressure over diastolic pressure, i.e. 120/80
Parasympathetic system
Dominates control of many visceral effectors under normal everyday conditions; examples include slowing heartbeat, increasing peristalsis, and increasing secretion of digestive juices and insulin; it counterbalances sympathetic function
Cells and matrix
Differs from epithelial tissue in the arrangement and variety of its cells and in the amount and kinds of extracellular matrix found between its cells; in addition to the relatively few cells embedded in the matrix of most types of connective tissue, varying numbers and kinds of fibers are also present; structural quality and appearance of the matrix and fibers determine the qualities of each type of connective tissue, i.e. the matrix of blood is a liquid but other types of connective tissue, such as cartilage, have the consistency of firm rubber; the matrix of bone is hard and rigid, although the matrix of connective tissues such as tendons and ligaments is strong and flexible
Cells
Discovered about 300 years ago by Robert Hooke who was looking through his microscope at plant material; instead of a single magnified piece, he saw many spaces created by cell walls; since they reminded him of miniature storerooms or "cells"; throughout all these years, thousands of people have examined thousands of plant and animal specimens and have determined that everything is composed of cells; the foundation of modern biology is that cells are the smallest structural units of living things; the human body is composed of trillions of cells.
endocrine glands
Ductless glands; secrete hormones (chemicals) into intercellular spaces; from there, the hormones diffuse directly into the blood and are carried throughout the body;each hormone molecule may then bind to a cell that has specific receptors for the hormone, triggering a reaction in the cell; diseases are numerous, varied, and sometimes spectacular; tumors or other abnormalities often cause a gland to secrete too much or too little hormone
Telophase
During this phase, cell division is completed; 2 nuclei appear and chromosomes become less distinct and appear to break up; as the nuclear envelope forms around the chromatin, the cleavage furrow completely divides the cell in two; before division is complete, each nucleus is surrounded by cytoplasm in which organelles have been equally distributed; by the end of this phase, 2 separate daughter cells, each having identical genetic characteristics, are formed; each daughter cell is now in interphase, fully functional and may undergo mitotic cell division itself in the future
cardiac cycle
Each complete heartbeat; includes the contraction (systole) and relaxation (diastole) of atria and ventricles; each cycle takes about 0.8 seconds to complete if the heart is beating at an average rate of about 72 beats per minute; most of the atrial blood moves into the ventricles passively before the atria have had a chance to contract; there is also a brief period at the beginning of ventricular contraction where there is no change in volume because it takes a moment for the ventricular pressure to overcome the force needed to open the semilunar valves; there is another period of constant volume as the ventricles begin to relax-before the mitral valves open and blood gushes in rapidly from the atria
bulbourethral glands (Cowper glands)
Each of them resembles a pea in size and shape; they are located just below the prostate gland and empty their secretions into the penile portion of the urethra; because the bulbourethral secretion is often released just before most of the rest of the semen is ejaculated, it is sometimes called the "pre-ejaculate"; the mucus like secretions of the bulbourethral glands serve many functions: they neutralize any residue of sperm-damaging acidic urine in the urethra, they also lubricate the urethra to protect sperm from friction damage and add to the external lubrication of the penis needed for intercourse; they contribute less than 5% of the seminal fluid volume ejaculated from the urethra
Masseter
Elevates the mandible; one of the 2 largest muscles in the muscles of mastication group
Pancreatic inlets/islets of Langerhans
Endocrine glands that are too tiny to be seen without a microscope; little clumps of cells scattered like islands in a sea among exocrine cells of the pancreas that secrete the pancreatic digestive juice; 2 most important cells are alpha cells (A cells) and beta cells (B cells); if pancreatic inlets secrete a normal amount of insulin, glucose enters the cells easily and a normal (normal fasting glucose is 70-100 mg of glucose in every 100 mL of blood) amount of glucose stays behind in the blood; if they secrete too much insulin, more glucose than usual leaves the blood to enter the cells, and blood glucose decreases
Comparative/environmental physiology
Examines how animals adapt to their environment
nitric oxide (NO)
Example of a very small molecule that diffuses directly across the plasma membrane of neurons rather than being released from vesicles
Respiration
Exchange of gases (oxygen and carbon dioxide) between a living organism and its environment; if the organism consists of only one cell, gases can move directly between it and the environment; if the organism consists of billions of cells, most of its cells are too far from the air for a direct exchange of gases; to overcome this difficulty, the lungs provide a place where air and a. circulating fluid (blood) ca come close enough to each other for oxygen to move out of the air into the blood while at the same time carbon dioxide moves out of the blood into the air; all of these respiratory processes require transport of gases by the blood; because a relatively constant set point concentration of these blood gases is required for survival, there are complex regulatory mechanisms that control them
internal respiration
Exchange of gases occurs between the blood and the systemic tissues of the body, which then use the oxygen in the biochemical pathways that transfer energy from nutrient molecules to ATP
Effects of exercise on immunity
Exercise physiologists have found that moderate exercise increases the number of WBCs, specifically granular leukocytes and lymphocytes; moderate exercises such as walking immediately after a surgery is often encouraged because of its immunity-strengthening effects
Lungs
Fairly large organs; deep grooves called fissures subdivide each lung into lobes; the R lung has 3 lobes and the L lung has 2; the narrow, superior position of each lung, up under the collarbone, is the apex; the broad, inferior portion resting on the diaphragm is the base; each lung is made up of all of the elements of the bronchial tree, alveoli, and pulmonary blood vessels - along with connective tissues, lymphatic vessels, and nerves; the lung is a combination of several kinds of structures that form an unit for respiration
Periodontal membrane
Fibrous; lines each tooth socket and anchors the tooth to the bone
Parietal pericardium
Fits around the heart like a loose-fitting sack, allowing enough room for the heart to beat
Blood
Fluid tissue that has many kinds of chemicals dissolved in it and millions upon millions of cells floating in it; as a general rule, most adults probably have between 4-6 liters of blood; normally accounts for 7-9% of the total body weight; the amount varies with the size of the person and males tend to have more blood than females; blood is slightly alkaline with a pH between 7.35 and 7.45 - always staying just above the chemically neutral point of 7.0; as blood cells mature, they move into the circulatory vessels
Gallbladder
Folded lining allows it to expand and act as an overflow reservoir for bile; also concentrates bile by reabsorbing water from bile back into the blood; when chyme containing liquid or fat enters the duodenum, it initiates a mechanism that contracts the gallbladder and forces bile into the small intestine; fats in chyme trigger the secretion of cholecystokinin from the intestinal mucosa of the duodenum; because bile pigments aren't removed from the blood by the gallbladder, no jaundice occurs if only the cystic duct is blocked
Hematopoiesis
Formation of new blood cells; 2 kinds of connective tissue - myeloid tissue and lymphoid tissue-make blood cells for the body
Lymphocytes
Formed by lymphoid tissue, which is found as white masses located chiefly in the lymph nodes, thymus, and spleen
Roof of the mouth
Formed by the hard and soft palates
Deltoid
Forms the thick, rounded prominence over the shoulder and arm; takes its origin from the scapula and clavicle and inserts on the humerus; powerful abductor of the arm
Cardiac muscle tissue
Forms the walls of the heart, and the regular but involuntary contractions of cardiac muscle produce the heartbeat; under the light microscope, cardiac muscle fibers have faint cross striations and thicker dark bands called intercalated disks; branch and connect to various other cardiac fiber branches to produce a 3-D interlocking mass of contractile tissue
Fibularis group/peroneus group
Found along the sides of the leg; as a group, these muscles evert and plantar flex the foot; a long tendon from one component of the group - the fibularis longs muscle tendon-forms a support arch for the foot
medulla rhythmicity area
Group of control centers in the medulla; produce the basic rhythm of breathing; a normal resting breathing rate is about 12-18 breaths a minute; 2 most important control centers in the medulla are VRG and DRG
capillary exchange
Function as exchange vessels-thus carrying out a central function of the cardiovascular system; i.e. glucose and oxygen move out of the blood in capillaries into interstitial fluid and then on into cells; carbon dioxide and other substances move in the opposite direction (that is, into the capillary blood from the cells); fluid is also exchanged between capillary blood and interstitial fluid; 2 opposing forces, osmosis and filtration, influence capillary exchange; osmosis is passive movement of water when some solutes cannot cross the membrane and filtration is passive movement of fluid resulting from a hydrostatic pressure gradient; the capillary exchange forces vary, depending on location; at the arterial end of a capillary, the outwardly directed forces are dominant and tend to move fluids from blood to tissue; at the venous end of a capillary, the inwardly directed forces are greater and thus tend to move fluids from tissue to blood; excess tissue fluids not moved into the blood are collected by the lymphatic system to be eventually returned to venous blood; factors that affect osmotic pressure (such as plasma albumin levels) or the hydrostatic pressure (such as blood pressure) that drives filtration can disrupt capillary exchange-perhaps resulting in dehydration or overhydration of tissue
Schwann cells
Glial cells that also form myelin sheaths but only in the PNS; each oligodendrocyte can form part of the myelin sheath around several axons but Schwann cells wrap entirely around one axon
Gonads
Gonads of men consist of a paint of main sex glands called the testes
Plasma membrane of a postsynaptic neuron
Has protein molecules embedded in it opposite each synaptic knob; these serve as receptors to which neurotransmitter molecules bind; this binding can initiate an impulse in the post-synaptic neuron by opening ion channels in the postsynaptic membrane; after impulse conduction by postsynaptic neurons is initiated, neurotransmitter activity is rapidly terminated; some neurotransmitter molecules are transported out of the synaptic cleft back into synaptic knobs; other neurotransmitter molecules are broken apart into inactive compounds by specific enzymes in the extracellular matrix of the synaptic cleft
Posture
Good posture means that body parts are held in the position that favor best function; these positions balance the distribution of weight and put the least strain on muscles, ligaments, tendons, and bones; skeletal muscle tone maintains posture by counteracting the pull of gravity; gravity tends to pull the head and trunk down and forward, but the tone in certain back and neck muscles pulls just hard enough in the opposite direction to overcome the force of gravity and hold the head and trunk erect
Electrocardiogram
Graphic record of the heart's electrical activity; also known as an ECG or EKG when speaking; skilled interpretation of these records may make the difference between life and death; a normal ECG tracing has 3 very characteristic deflections, or waves, called the P wave, the QRS complex, and the T wave; these deflections represent the electrical activity that regulates the contraction or relaxation of the atria or ventricles; by looking at changes in blood flow and volume, you will discover that ECG deflections occur before myocardial contractions; this occurs because depolarization triggers contractions and a trigger always comes before the event that is triggered; damage to cardiac muscle tissue that is caused by a MI or disease affecting the heart's conduction system results in distinctive changes in the ECG; therefore, ECG tracings are extremely valuable in the diagnosis and treatment of heart disease
Sympathetic postganglionic neurons
Have dendrites and cell bodies in sympathetic ganglia; sympathetic ganglia are located at front of and at each side of the spinal column; since short fibers extend the sympathetic ganglia, they look a little like two chains of beads and are often referred to as the sympathetic chain ganglia; axons of sympathetic postganglionic neurons travel in spinal nerves to blood vessels, sweat glands, and arrector pili hair muscles all over the body; separate autonomic nerves distribute many sympathetic postganglionic axons to various internal organs
Isotonic
Having the same solute concentration as another solution.
Dendritic cell (DC)
Highly branched cells are produced in bone marrow ands are released into the bloodstream; some remain in the blood but many migrate to tissues in contact with the external environment-the skin, respiratory lining, digestive lining, and so on; resident DCs in these barrier regions help protect us from threatening particles and cells
Mouth (oral cavity)
Hollow chamber with a roof, a floor and walls; food enters, or rather is ingested into, the digestive tract through the mouth, and the process of digestion begins immediately; lined with mucous membrane like the remainder of the digestive tract
Negative feedback
Homeostatic mechanism whereby a response opposes original stimulus; use insulin as an example; when released from endocrine cells in the pancreas, insulin lowers "blood sugar levels" or glucose concentration in the blood; normally, high blood sugar levels occur after a meal once the absorption of sugars from the digestive tract have taken place; the elevated blood sugar stimulates the release of insulin from the pancreas; insulin then assists in the transfer of sugar from the blood into cells, causing blood sugar levels to drop back toward the normal set point; as blood sugar levels drop, the endocrine cells in the pancreas slow their production and release of insulin; these responses are "negative because they reverse the direction of a disturbance to the stability of the internal environment of the body"; this is called a negative feedback control mechanism because it reverses the change in blood sugar level
Cholecystokinin (CCK)
Hormone travels through the bloodstream and promotes contraction of the gallbladder-and consequently bile flows into the duodenum; secretion of CCK is a good example of a hormone acting to regulate GI motility
Cretinism
Hyposecretion of the thyroid hormones during the formative years; characterized by a low metabolic rate, retarded growth and sexual development, and often mental retardation
irregular bone
I.e. vertebrae or spinal bones
Bond
If Atoms can "share" their single electrons with each other, then both will have full energy shells, making them more stable as a molecule than either would be as an atom; other atoms can donate or borrow electrons until the outermost energy level is full and then form crystals
Acidosis
If the alkalinity of your blood decreases toward normal, you are a very sick person; even with this condition, blood almost never becomes acidic (below pH 7), it just becomes les alkaline than normal
Vaccines
In 1789, surgeon, Edward Jenner, inoculated his young son and 2 others against smallpox; using material from a patient's blisters with the milder disease swine pox, he was able to trigger immunity to smallpox - the world's 1st vaccination ; in 1796, he found that material from cowpox blisters worked even better; a disease that had killed millions of people worldwide eventually disappeared from the human population because of these efforts; interest in smallpox vaccinations has resurfaced because of the the threat of smallpox as a weapon ; immunologists also continue to work on vaccines for Ebola, malaria, AIDS, and even heart disease and cancer; many doctors use vaccines to boost immune systems of their clients and there are doctors who treat disorders of the immune system itself
Chromatin granules
In the nucleus; made up of proteins around which are wound segments of DNA; DNA is described as the chemical "cookbook" of the body; since it contains the code for building both structural and functional proteins, DNA determines everything from gender and metabolic rate to hair color in every human being
Types of teeth
Incisors (have very sharp cutting edges), canines/cuspids (have more pointed ends well suited for piercing and tearing), premolars/bicuspids, and molars/tricuspids with their 2/3 grinding "cusps" provide a large surface area to effectively crush ingested food material; together the teeth provide for effective chewing or mastication of a wide variety and size of ingested food
Pleurisy
Inflammation of the pleura that causes pain when the parietal and visceral pleural membranes rub together
Overview of kidney function
Kidneys are vital organs; the function they perform, that of forming urine, is essential for homeostasis and maintenance of life; early in the process of urine formation, fluid, electrolytes, and wastes from metabolism are filtered from the blood and enter the nephron; the kidneys adjust their output to equal the intake of the body; by eliminating wastes and adjusting fluid balance, the kidneys play an essential part in maintaining homeostasis; homeostasis can't be maintained-nor can life itself-if the kidneys fail and the condition is not soon corrected; nitrogenous waste products accumulate as a result of protein breakdown and quickly reach toxic levels if not excreted; if kidney function is greatly reduced because of aging, injury, or disease, life can be maintained by using an artificial kidney to cleanse the blood of wastes; kidney also plays a role in regulating the levels of many chemical substances in the blood such as chloride, sodium, potassium, and bicarbonate; the kidneys also regulate the proper balance between body water content and salt by selectively retaining/excreting both substances as requirements demand
Dyspnea
Labored or difficult breathing and is often associated with hypoventilation
Mesentery
Large double fold of peritoneal tissue that anchors the loops of the digestive tract to the posterior wall of the abdominal cavity
Cerebrum
Largest and uppermost part of the brain; if you were to look at the outer surface of the cerebrum, the first features you would notice are the many ridges and grooves; white matter, made up of bundles of nerve fibers (tracts) composes most of the interior of the cerebrum; hard to answer what functions the cerebrum performs because the neurons of the cerebrum don't function alone; they function with many other neurons in many other parts of the brain and in the spinal cord; neurons of these various structures continually bring impulses to cerebral neurons and also continually carry impulses away from them; a summary of the major cerebral functions are: consciousness, thinking, memory, sensations, emotions, and willed movements
Parotid glands
Largest of the salivary glands; lie just below and in front of each ear at the angle of the jaw; contain only serous-type secretory cells, which produce a watery, or serous, type of saliva containing enzymes but not mucus
Diploe
Layer of cancellous bone located between outer layers of compact bone
Pancreas
Lies behind the stomach in the concavity produced by the C shape of the duodenum; both an exocrine gland that secretes pancreatic juice into ducts and an endocrine gland that secretes hormones into the blood; pancreatic juice is the most important digestive juice; it contains enzymes that digest all three major kinds of nutrients-carbohydrates, proteins, and lipids; also contains sodium bicarbonate, an alkaline substance that neutralizes the hydrochloride acid in the gastric juice that enters the intestines; pancreatic juice enters the duodenum of the small intestine at the same place that bile enters; the common bile and pancreatic ducts open into the duodenum at the major duodenal papilla; between the cells that secrete pancreatic pancreatic juice into ducts lie clusters of cells that have no contact with any ducts; these are the pancreatic islets (islets of Langerhans) which contain the endocrine cells that secrete the hormones of the pancreas-mainly insulin and glucagon
Thyroid gland
Lies in the neck just below the larynx; thyroid tissue is organized into many chambers called thyroid follicles; each thyroid follicle is filled with a thick fluid having many fine, suspended particles called colloid; secretes 2 thyroid hormones and the hormone calcitonin (CT)
Ovarian follicles
Little pockets in which egg cells/ova develop; also secrete estrogen
Hypothalamus
Located below the thalamus; the posterior pituitary gland, the stalk that attaches it to the undersurface of the brain, and areas of gray matter located in the side walls of a fluid-filled space called the third ventricle are extensions of the hypothalamus; when measured by size, it is one of the least significant parts of the brain, but measured by its contribution to healthy survival, it is one of the most important brain structures; exerts major control over virtually all internal organs; among the vital functions that it helps control are the heartbeat, constriction and dilation of blood vessels, plays an essential role in maintaining the body's water balance, and contractions of the stomach and intestines; some neurons function in a surprising way: they make the hormones that the posterior pituitary gland secretes into the blood; some of the neurons function as endocrine (ductless) glands; their axons secrete chemicals called releasing hormones into the blood which then carries them to the anterior pituitary gland; releasing hormones control the release of certain anterior pituitary hormones; these then influence the hormone section of other endocrine glands; thus, they hypothalamus indirectly helps control the functioning of every cell in the body; crucial part of the mechanism for maintaining body temperature; also involved in functions such as sleep cycles, the control of appetite and many emotions involved in pleasure, fear, anger, sexual arousal and pain
Thymus
Located in the mediastinum; small structure weighing about 20 grams; in infants, it may extend up into the neck as far as the lower edge of the thyroid gland; has a cortex and a medulla; both are mainly composed of leukocytes (white blood cells); the location where many of the immunity cells develop; it is a vital immunity mechanism
Thalamus
Located just above the hypothalamus; dumbbell-shaped section of gray matter; each enlarged end of the dumbbell lies in a lateral wall of a fluid-filled chamber called the third ventricle; the thin center section of the thalamus passes from L to R through this ventricle; composed mainly of dendrites and cell bodies of neurons that have axons extending up toward the sensory areas of the cerebrum; it performs the following functions: 1) helps produce sensations, its neurons relay impulses to the cerebral cortex from the sense organs of the body; 2) associates sensations with emotions, almost all sensations are covered by a feeling of some degree of pleasantness or unpleasantness; it is unknown how these feelings are produced but it seems to be associated with the arrival of sensory impulses in the thalamus; 3) plays a part in the so-called arousal/alerting mechanism
Larynx (voice box)
Located just below the pharynx, composed of 9 pieces of cartilage - the largest of them - the thyroid cartilage is also known as the "adam's apple"; 2 short fibrous bands (vocal cords) stretch across the interior of the larynx; muscles that attach to the larynx cartilages can pull on these cords in such a way that they become tense (high pitched voice) or relaxed (low pitched voice)
Orbital
Location of electrons; if an atom is neutral, there is one electron for every proton; electrons don't stay still; each orbital can hold two electrons
medulla oblongata
Lowest part of the brainstem; an enlarged, upward extension of the spinal cord; it lies just inside the cranial cavity above the large hole in the occipital bone called the foramen magnum
Antigen-presenting cells (APCs)
Macrophages and DCs don't just destroy threatening cells and particles; they ingest a cell or particle, remove its antigens, and display some of them on their cell surfaces; the displayed antigens can then be presented to other immune cells to trigger additional, specific immune responses
MRI
Magnetic Resonance Imaging
Testosterone
Masculinizes - the various characteristics that we think of as "male" develop because of testosterone's influence; promotes and maintains the development of the male accessory organs; has a stimulating effect on protein anabolism - it is an anabolic steroid hormone - responsible for the greater muscular development and strength of the male
Nonspecific immunity
Maintained by mechanisms that attack any irritant or abnormal substance that threatens the internal environment; confers general protection rather than protection from a specific threatening cell or chemical; often called innate immunity because we are born with nonspecific defenses that do not require exposure to anything harmful or threatening; these responses are more rapid than specific immune responses so they are often the "first responders" when threats occur in the body; examples include skin and mucous membranes are nonspecific mechanical barriers that prevent entry into the body by bacteria and many other substances such as toxins and harmful chemicals; another example is tears which wash harmful substances from the eyes, and mucus traps foreign material that may enter through the respiratory tract; phagocytosis of bacteria by WBCs is a nonspecific form of immunity
Sex hormones
Male hormones (androgens) that are similar to testosterone; secreted in small amounts in adults but play an early role in development of the reproductive organs; in women, they may stimulate the sex drive; in men, so much testosterone is secreted by the testes that adrenal androgens are physiologically irrelevant
Deep
Means "farther away from the body surface"
Superficial
Means "nearer the surface"
Blood tissue
Most unusual form of connective tissue because its matrix - blood plasma - is liquid; has transportation and protective functions in the body; red blood cells, white blood cells, and platelets are the cell types common to blood
Lysososome
Membranous-walled organelles that when active look like small sacs, often with tiny particles in them; since lysosomes contain enzymes that promote hydrolysis, they can break apart (digest) large nutrient molecules so their nickname is "digestive bags"; they can also digest substances other than nutrients, i.e. they can digest and thereby destroy microbes that invade the cell so lysosomes can help protect cells against destruction by microbes
Elements
Method of classifying substances; pure substances, composed of only one of more than 100 types of atoms that exist in nature; 4 types of atoms (oxygen, carbon, hydrogen and nitrogen) make up 96% of the human body but there are traces of about 20 other elements in the body.
second messengers
Molecules within the cell that are activated as a result of chemical reactions that occur after the hormone attaches to its specific receptor site; one example occurs when the hormone-receptor interaction changes energy-rich ATP molecules inside the cell into cAMP (cyclic adenosine monophosphate); cAMP serves as the second messenger, delivering information inside the cell that regulates the cell's activity; provides communication within a hormone's target cell, i.e. cAMP causes thyroid cells to respond to thyroid-stimulating hormone by secreting a thyroid hormone such as thyroxine
DNA (deoxyribonucleic acid)
Mostly make up chromosomes which contain all the info needed to make all the proteins of the cells; structurally, the DNA molecule resembles a long, narrow ladder made of a pliable material - it is twisted round and round its axis, taking on the shape of a double helix; each DNA molecule is made up of many smaller units called nucleotides; each nucleotide is made up of a sugar, a phosphate and a base; each step in the DNA ladder consists of a pair of bases; has a content of genetic information totaling about 3 billion base pairs in 19,000 or so protein-coding genes; sections of DNA that do not code for protein structures have other functions like regulating protein synthesis and turning genes on and off; since DNA directs the shape of each protein, it also directs the function of each protein in a cell
somatic nervous system
Motor nerves that control the voluntary actions of skeletal muscles
Effector
Motor neuron axon forms a synapse with an organ that puts nerve signals "into effect"; usually muscles or glands, and muscle contractions and gland secretions are the kinds of reflexes operated by these effectors
eccentric contraction
Muscle lengthens but still provides work, i.e. lowering the book slowly and safely requires eccentric concentration of the biceps muscle;
Origin
Muscle's attachment to a more stationary bone
Insertion
Muscle's attachment to the more movable bone
Muscles of the trunk
Muscles of the anterior or front side of the abdomen are arranged in 3 layers (external oblique, internal oblique, and transversus abdominis) with the fibers in each layer running in different directions like the layers of wood in a sheet of plywood; the result is a very strong "girdle" of muscle that covers and supports the abdominal cavity and its internal organs
Renal papilla
Narrow, innermost end of a pyramid
Pharanyngeal tonsils
Near the posterior opening of the nasal cavity; known as adenoids when they become swollen
Lower abdominopelvic regions
R and L iliac regions (also called inguinal regions) and the hypogastric region lie below an imaginary line across the abdomen at the level of the top of the hip bones
Changes in blood flow during exercise
Not only does the overall rate of blood flow increase during exercise, but also the relative blood flow through the different organs of the body changes; during exercise, blood is routed away from the kidneys and digestive organs and toward the skeletal muscles, cardiac muscle and skin; rerouting of blood is accomplished by contracting muscles in the arterioles of some tissues (thus reducing blood flow) while relaxing arterioles in other tissues (thus increasing blood flow); how can homeostasis be better maintained by these changes? One reason is that glucose and oxygen levels drop rapidly in muscles as they use up these substances to produce energy for exercising; increased blood flow restores normal levels of glucose and oxygen more rapidly; blood that has been warmed up in active muscles flows to the skin for cooling; this helps keep the body temperature from getting too high
Malocclusion
Occurs when missing teeth create wide spaces in the dentition, when teeth overlap, or alignment of the maxillary and mandibular dental arches; malocclusion that results in protrusion of the upper front teeth, causing them to hang over the lower front teeth, is called overbite, whereas the positioning of the lower front teeth outside the upper front teeth is called underbite; may cause significant problems and chronic pain in the functioning of the temporomandibular joint (TMJ), contribute to the generation of headaches, or complicate routine mastication of food; fortunately, even severe malocclusion problems can be corrected by the use of braces and other dental appliances; orthodontics is that branch of dentistry that deals with the prevention and correction of positioning irregularities of the teeth and malocclusion
triceps brachii
On the posterior or back surface of the arm; has 3 heads of origin from the shoulder girdle and inserts into the olecranon muscle process of the ulna; an extensor of the elbow and thus performs a straightening function; also called the boxer's muscle because it's responsible for delivering blows during flights
Levels of regulation
One level of control is regulating the secretion of a particular hormone but that regulates specific functions in the target cells, which in turn changes some particular function of the body, i.e. feedback may trigger the secretion of a "releasing" hormone that targets another gland and triggers the secretion of that second gland's hormone; feedback may instead trigger autonomic nervous stimulation of a gland, which then secretes a releasing hormone; in turn, the releasing hormone triggers the release of another hormone that regulates its target cells, which change their functions to produce an effect that changes a variable to move back toward its set point; ALL the levels of control are receiving and reacting to feedback-thus providing extra efficiency and precision to the homeostatic control of body function
Body cavities
Open spaces or cavities that contain compact, well-ordered arrangements of internal organs
skeletal muscles
Organ composed mainly of skeletal muscle fibers (elongated contractile cells that look like long, tapered cylinders) and connective tissue; fibrous connective tissue wraps around each individual muscle fiber , then continues as it wraps around fascicles and then forms a "wrapper" around the entire muscle organ; has a unique cytoskeleton structure; organized into many long cylinders, each made up of 2 kinds of thick and thin myofilaments;held together in parallel groups, allowing the muscle fibers to all pull together in the same direction; most muscles extend from one bone across a joint to another bone; one of the 2 bones is usually more stationary during a given movement than the other;Under the microscope, appear threadlike and cylindrical and in bundles; characterized by many crosswise stripes and multiple nuclei; this type of muscle tissue has 3 names: skeletal muscle because it attaches to the bone, striated muscle because of its cross stripes or striations, and voluntary muscle because its contractions can be controlled voluntarily
Adductor muscles
Originate on the bony pelvis and insert on the femur; located on the inner or medial side of the thighs; these muscles adduct, or press, the thighs together
International Normalized Rate (INR)
PT is reported in seconds; INR is a mathematical calculation and is reported as a number; an INR of 0.8 to 1.2 is considered normal; in regulating anticoagulant therapy, keeping the INR between 1.5 and 3 will help ensure the prevention of unwanted blood coagulation in "at risk" individuals; by monitoring the changes in the INR, a physician can adjust the dose of anticoagulant drug needed yo maintain an appropriate level of anticoagulant effect
Renal colic
Pain caused by the passage of a kidney stone; kidney stones cause intense pain if they have sharp edges or are large enough to distend the walls or cut the lining of the ureters or urethra as they pass from the kidneys to the exterior of the body; some of the pain is caused by tearing or stretching of the urinary lining-along with the accompanying inflammation; however, much of the pain is associated with cramping of muscles that attempt to push a kidney stone forward
Centrioles
Paired organelles found within the chromosome; 2 of these rod-shaped structures exist in every cell and are arranged so that they lie at right angles to each other; each centriole is composed of microtubules that play an important role in forming a tapered framework ("spindle")that moves chromosomes during cell division
Gonads (female)
Paired ovaries; the female sex cells, or ova, are produced in the ovaries
Osmosis
Passive movement of water molecules through water channels in a selectively permeable membrane when some of the solute cannot cross the membrane (because there are no open channels or carriers for that solute)
endocrine system
Performs communication and control functions like the nervous system, however, the endocrine system provides slower but longer-lasting control by way of hormones (chemicals) secreted to and circulated into the blood; all organs of the endocrine system are glands but not all glands are organs of the endocrine system; only endocrine glands belong to this system, not exocrine glands; endocrine glands are ductless glands
Research, issues and trends - second messenger systems
Pioneered by Earl Sutherland who received the 1971 Nobel Prize for formulating the second messenger hypothesis; later, the important role of the G protein in getting the signal from the receptor to the enzyme that forms cAMP was discovered; the role of nitrous oxide (NO) has also been discovered; by figuring out how hormones work, we can understand how and why things go wrong with them; once we figure out the process of disease mechanisms, we hope that tests can be developed to screen for problems or develop drugs that can "fix" the broken mechanisms and cure the disease
Glycogen
Polysaccharide of glucose that is stored by the liver; each glycogen molecule is a chain of glucose molecules joined together
cancellous bone/spongy bone
Porous bone tissue located on the inside of individual bones; contains many spaces; cavities are filled with red or yellow bone marrow
Crown
Portion that is exposed and visible in the mouth; made largely of a bone-like material called dentin that is covered by enamel
seminal vesicles
Pouchlike glands that contribute about 60% of the seminal fluid volume; their secretions are yellowish, thick, and rich in the sugar fructose; this fraction of the seminal fluid helps provide a source of energy for the highly motile sperm
Lower esophageal sphincter (LES)
Prevents backflow of acidic stomach contents; also called the cardiac sphincter
Gastrocnemius
Primary calf muscle; has 2 fleshy components arising from both sides of the femur; inserts through the calcaneal (Achilles) tendon into the heel bone or calcaneus; responsible for plantar flexion of the foot; sometimes called the toe dancer's muscle because tit is used to stand on tiptoe
Digestion
Process of breaking down the ingested food material into simpler nutrients; both mechanical and chemical in nature; the teeth are used to physically break down large chunks of food before it is swallowed; the churning of food in the stomach then continues the mechanical digestive process
Ingestion
Process of taking complex foods into the GI tract
Coronary circulation
Process of the delivery of oxygen and nutrient-rich arterial blood to cardiac muscle tissue and the return of oxygen-poor blood from this active tissue to the venous system
Pulmonary ventilation (breathing)
Process that moves air in and out of the lungs
testes (testicles)
Produce the male sex cells - the sperm or spermatozoa; also produce the hormone testosterone; located in the pouch like scrotum, which is suspended outside of the body cavity below the penis; this exposed location provides an environment about 1-3 degrees Celsius cooler than normal body temperature, an important requirement for the normal production and survival of sperm; each testis is a small, oval gland about 3.8 cm (1.5 in) long and 2.5 cm (1 in) wide; shaped like an egg that has been flattened slightly from side to side
ATP (adenosine triphosphate)
Produced in the mitochondria using energy from nutrients and is capable of releasing that energy to do work in the cell; for active transport processes to occur, the breakdown of ATP and the use of the released energy are required; a molecule that transfers energy from the breakdown of food molecules to cell processes
muscle tone
Produces continuous tension on the skeleton; also helps maintain a stable body position, or posture; skeletal muscles also produce heat and help maintain homeostatic balance of body temperature
Hypersecretion
Production of too much hormone by a diseased gland
Rib and breastbone
Protect vital organs in the chest (heart and lung)
Rh-negative blood
RBCs do not have the Rh antigens on their surfaces; plasma never naturally contains anti-RH antibodies; if RH-positive blood cells are introduced into an Rh-negative person's body, anti-Rh antibodies soon appear in the recipient's blood plasma; w/o appropriate precautions, there could be some danger for a bay born to an Rh-negative mother and a RH-positive father; if the baby inherits the Rh-positive trait from his father, the Rh factors in his RBCs may stimulate the mother's body to form anti-Rh antibodies; then, if she later carries another RH-positive fetus, the fetus may develop a type of hemolytic anemia called erythroblastosis fetalis, caused by the mother's Rh antibodies reacting with the baby's Rh-positive cells
Gastrointestinal (GI) tract
Refers only to the portion that includes the stomach and intestines but is often used to designate the entire digestive tract; hollow tube is about 9 meters (29 feet) long so the food we eat and even the nutrient materials released by the digestive process are not "part of the body" until they have passed through the wall of the GI tract and entered the internal environment
Eupnea
Refers to a normal respiratory rate; the need for oxygen and carbon dioxide exchange is being met, and the individual is usually not aware of the breathing pattern
synergist muscles
Refers to the other muscles that help in producing the movement
Homeostasis
Relative constancy of the internal environment
Astrocytes
Relatively large glia that look somewhat like stars because of the threadlike extensions that jut out from their surfaces; name means "star cells"; their threadlike branches attach to neurons and to small blood vessels, holding these structures close together
Digestion
Requirement for life; how we process the food we eat so the nutrients can be extracted and then absorbed for use by the millions of body cells for energy
Sexual reproduction
Requires 2 parent organisms, a male and a female, each of which contributes half of the nuclear chromosomes needed to form the first cell of an offspring; a new mixture of genes in each offspring increases the variety of genetic characteristics in the population; this variety makes it more likely that in the event of environmental changes or a natural disaster, there will be at least some individuals likely to survive and carry on the reproductive line
Cartilage
Resembles and differs from bone; both consist more of intracellular substance than cells; innumerable collagenous fibers reinforce the matrix of both tissues; however, in cartilage, the fibers are embedded in firm gel INSTEAD of a calcified cement substance like in bone; as a result, cartilage has the flexibility of a firm plastic
cell-mediated immunity
Resistance to disease organisms that results from the actions of cells-chiefly, sensitized T cells; one group of activated T cells kills infected cells and tumor cells directly; when bound to antigens, these cytotoxic T cells release a substance that acts as a specific and lethal poison against the abnormal cell; activated T cells called helper T cells produce their deadly effects indirectly by means of chemical signals that they release into the area around enemy cells; among these is a substance that attracts macrophages into the vicinity of the enemy cells; the assembled macrophages then destroy the cells by phagocytosis (ingesting and digesting) them; helper T cells also release the cytokines needed to help trigger the activation of B cells; a 3rd group of T cells called regulatory T cells helps shut down an immune reaction after the antigens have been destroyed and also helps prevent inappropriate immune reactions
Smooth (visceral) muscle tissue
Said to be involuntary because it is not under conscious or willful control; under a microscope, smooth muscle cells are seen as long, narrow fibers but not nearly as long as skeletal or striated fibers; individual muscle cells appear smooth and have only one nucleus per fiber; helps form the walls of blood vessels and hollow organs such as the intestines and other tube-shaped structures in the body; contractions of smooth muscle propel material through the digestive tract and help regulate the diameter of blood vessels; contraction of smooth muscle in the tubes of the respiratory system, such as the bronchioles in the lungs, can impair breathing and result in asthma attacks and labored respiration
Basophils
Secrete histamine which is released during inflammatory reactions; also produce an anticoagulant called heparin which helps prevent blood from clotting as it flows through the blood vessels of the body
Plasma cells (effector cells)
Secrete huge amounts of antibody into the blood-roughly 2000 antibody molecules per second by each plasma cell for every second of the few days it lives; antibodies circulating in the blood constitute an enormous, mobile, ever-on-duty army; "antibody factories" of the body; these antibodies are formed on the ER of the cell
Atrial natriuretic hormone (ANH)
Secreted by cells in the wall of the heart's atria (upper chambers); important regulator of fluid and electrolyte homeostasis and is an antagonist to aldosterone; ANH stimulates loss of sodium ions and water
Ghrelin
Secreted by epithelial cells lining the stomach and boosts appetite, slows metabolism and reduces fat burning; may be involved in the development of obesity
Leptin
Secreted by fat-storing cells throughout the body; seems to regulate how hungry or full we feel and how fat is metabolized by the body; researchers are now looking to see how it works with other hormones in the hopes of finding ways to treat patients with obesity, DM and other disorders involving fat storage
Cheyne-Stokes respiration (CSR)
Series of cycles of alternating apnea and hyperventilation; may also occur in critical diseases such as congestive heart failure, brain injuries or brain tumors; CSR may also occur in the case of a drug overdose
lymphatic vessels
Similar in many ways to blood capillaries; both types of vessels are microscopic and both are formed from sheets that consist of a single cell layer of simple squamous epithelial called endothelium; the flattened endothelial cells that form blood capillaries fit tightly together so that large molecules cannot easily enter/exit from the vessel; the "fit"between endothelial cells forming the lymphatic capillaries is not as tight so the lymphatic capillaries are more porous and allow larger molecules, including proteins and other substances; as well as the fluid itself, to enter the vessel and eventually return to the general circulation; have a "beaded" appearance , resulting from the presence of valves that assist in maintain an one-way flow of lymph; these valves sometimes cause lymph to back up behind them and cause swellings that look like beads;
Osmotic pressure
Since water moves into a space and there is no exchange of solutes, a change in fluid may result; osmotic pressure is that fluid pressure
intercalated discs
Site where The plasma membranes of adjacent cardiac fibers come in contact with each other
Diencephalon
Small but important part of the brain located between the midbrain below and the cerebrum above; consists of 3 major structures: hypothalamus, thalamus and pineal gland
pitutiary gland
Small but mighty structure; no larger than a pea; it is really 2 different types of glands - the adenohypophysis and the neurohypophysis; lies buried deep in the cranial cavity, in a well-protected location; this protected location suggests how important this gland is; sits in the sella turcica
Microvilli
Small, finger-like projections of the plasma membrane of some cells; have microfilaments inside them that produce wobbly movement and thus make absorption even more difficult; these projections increase the surface area of the cell and thus increase its ability to absorb substances, i.e. cells that line the small intestine are covered with microvilli that increase the absorption of nutrients into the blood
Effects of exercise on skeletal muscle
Some of the benefits of regular, properly practiced exercise are greatly improved muscle tone, better posture, more efficient heart and lung function, less fatigue, and looking and feeling better; skeletal muscles undergo changes that correspond to the amount of work they do
Growth hormone (GH)
Speeds up the digested proteins (amino acids) out of the blood and into the cells which accelerates the cells' anabolism; also affects fat and carbohydrate metabolism; accelerates fat catabolism (breakdown) but slows glucose catabolism; this means that less glucose leaves the blood to enter cells so the amount of glucose in the blood increases; growth hormone and insulin have opposite effects on blood sugar
Spermatogenisis
Sperm production; from puberty on, the seminiferous tubules continuously form spermatozoa; from puberty on, the seminiferous tubules continuously form sperm;
Shape of epithelial cells
Squamous - flat and scale like; cuboidal-cube-shaped; columnar - higher than they are wide; transitional - varying shapes that can stretch
Spermatagonia
Stem cells located near the outer edge of each seminiferous tubule; this is how the testes prepare for sperm production before puberty; when a boy enters puberty, circulating levels of FSH cause spermatagonia to undergo a unique series of cell divisions to produce sperm cells; when the spermatagonium undergoes mitosis and cell division occurs under the influence of FSH, it produces 2 daughter cells; one of these cells remains as a spermatagonium and the other forms another type of cell called a primary spermatocyte; these primary spermatocytes then undergo another type of cell division characterized by meiosis, which ultimately results in sperm formation
Corticoids
Steroid hormones that are secreted by the three cell layers/zones of the adrenal cortex
luteinization
Stimulates the formation of a golden body, the corpus luteum, from the ruptured follicle
Follicle-stimulating hormone (FSH)
Stimulates the primary ovarian follicles in an ovary to start growing and to continue developing to maturity (that is, to the point of ovulation); also stimulate follicle cells to secrete estrogens; in the male, FSH stimulates the seminiferous tubules to grow and form sperm
Pylorus
Stomach's lower apex section, which joins the 1st part of the small intestine
transitional epithelium
Stratified transitional epithelium is found in body areas subject to stress and must be able to stretch; in many instances, up to 10 layers of differently shaped cells of varying sizes are present in the absence of stretching; when stretching occurs, the epithelial sheet expands,, the # of cell layers decreases, and cell shape changes from roughly cuboidal to nearly squamous (flat) in appearance, i.e. the wall of the urinary bladder; the ability of the transitional epithelium to stretch easily without damage keeps the bladder wall from tearing as urine fills the bladder.
Strength of heart contractions
Strength and rate of the heartbeat affect cardiac output and therefore BP; each time the L ventricle contracts, it squeezes a certain volume of blood (the stroke volume) into the aorta and into other arteries; the stronger each contraction is, the more blood it pumps into the aorta and arteries; conversely, the weaker each contraction is, the less blood it pumps
Pulmonary stretch reflexes
Stretch receptors in the lungs are located throughout the pulmonary airways and in the alveoli; nervous impulses generated by these receptors influence the normal pattern of breathing and protect the respiratory system from excess stretching caused by harmful overinflation; when the tidal volume of air has been inspired, the lungs are expanded enough to stimulate stretch receptors that then send inhibitory impulses to the inspiratory center; relaxation of inspiratory muscles occurs, and expiration follows; after expiration, the lungs are sufficiently deflated to inhibit the stretch receptors, and inspiration is then allowed to start again
automatic nervous system (ANS)
Subdivision of the peripheral nervous system; consists of structures that regulate the body's automatic/involuntary functions (i.e. heart rate, contractions of the stomach and intestines, and secretion of chemical compounds by glands); consists of certain motor neurons that conduct impulses from the spinal cord or brain stem to cardiac and smooth muscle tissues and epithelial gland tissue; consists of 2 divisions: the sympathetic division and the parasympathetic division; function is to regulate the body's automatic, involuntary functions in ways that maintain or quickly restore homeostasis; many internal organs are dually innervated which means that they receive fibers from parasympathetic and sympathetic divisions; parasympathetic and sympathetic impulses continually bombard them and influence their function in opposite or antagonistic ways
nuclear envelope
Surrounds a cell nucleus; made up of 2 separate membranes; has many tiny openings called nuclear pores that permit large molecules into and out of the nucleus
Perineurium
Surrounds each fascicle; thin and fibrous
Degluition
Swallowing; complex process requiring the coordination of pharyngeal muscles and other muscles and structures in the head and neck; regulation of voluntary swallowing movements is dependent on nervous impulses originating in the motor cortex of the cerebrum; involuntary movements are regulated by impulses originating in the swallowing or "degluition center" located in the medulla and pons of the brainstem
Estrogen
The "feminizing" hormone; involved in the development of breasts and external genitals; also responsible for development of adult female body contours and initiating the menstrual cycle
Smooth muscle
Tapered at each end and have a single nucleus; sometimes called nonstriated muscle fibers because they lack cross stripes or striations; have a smooth, even appearance when seen under a microscope; called involuntary because we don't have control over their contractions; forms an important part of blood vessel walls and of many hollow internal organs (viscera) such as the gut, urethra and ureters; also sometimes called visceral muscle because of its location in many visceral structures; although we can't willfully control the contractions, the contractions are highly regulated which promotes efficient food passage through the digestive tract or urine through the ureters into the bladder; all 3 muscle types specialize in contraction or shortening; every movement we make is produced by contractions of skeletal muscle; contractions of cardiac muscle fibers pump the blood through the heart, and smooth muscle contractions help pump blood and other substances through our other hollow organs
Placenta
Temporary endocrine gland produced during pregnancy; produces chorionic gonadotropins, estrogen and progesterone; during the earliest weeks of pregnancy, the kidneys excrete large amounts of chorionic gonadotropins into the urine which led to developing the first pregnancy tests
Leukemia
Term used to describe a number of blood cancers affecting the WBCs; in almost every form of leukemia, marked leukocytosis (elevated WBC count) occurs; leukocyte counts in excess of 100,000 in circulating blood is common; many of the additional WBCs do not function properly; different types of leukemia are identified as either chronic or acute based on how quickly symptoms appear after the disease begins; leukemia's are referred to as lymphocytic or myeloid depending on where the disease develops in the body
Oxygen therapy
The administration of oxygen to individuals suffering from hypoxia-an insufficient oxygen supply to the tissues; individuals with certain respiratory problems, such as emphysema, may require supplemental oxygen in order to maintain a normal lifestyle; oxygen (O2) in the form of compressed gas is commonly stored in and dispensed from small, green metal cylinders/tanks; because the oxygen dispensed from such tanks is often cold and dry, it is often warmed and moistened, generally by bubbling the released gas through water, to prevent damage to the respiratory tract; supplemental oxygen is delivered through a mask or tubes that lead into the nasal passage (nasal prongs)
Adrenergic fibers
The axon of a sympathetic postganglionic neuron which releases the neurotransmitter norepinephrine (noradrenaline)
Human Organism
The body as a whole; all the atoms, molecules, cells, tissues, organs and systems
Autonomic neurotransmitters
The chemical compounds released from the axon terminals of autonomic neurons; that each division of the ANS signals its effectors with a different neurotransmitter explains how an organ can tell which division is stimulating it, i.e. the heart responds to acetylcholine from the parasympathetic division by slowing down but if there is a presence of norepinephrine from the sympathetic division, the heart speeds up
Blood pressure gradient
The difference between 2 blood pressures; the blood pressure gradient for the entire systemic circulation is the difference between the average/mean blood pressure in the aorta and the blood pressure at the termination of the venue cavae where they join the R atrium of the heart; vitally involved in keeping the blood flowing; when a BP gradient is present, blood circulates but when there isn't one blood doesn't circulate, i.e. if BP in the arteries decreases and equal to the pressure in the arterioles, there would be no BP gradient between arteries and arterioles meaning circulation stops and soon life ends
Common bile duct
The duct that carries bile from the gallbladder and liver to the small intestine (duodenum); if a gallstone blocks the common bile duct, bile could not drain into the duodenum; feces would then appear gray-white because the pigments from bile gives feces its characteristic color; if liver secretions slow down as a result of the backup, bile pigments would not be removed from the blood; jaundice would result
Ejaculation
The forceful ejection of fluid containing sperm into the female vagina during sexual intercourse is only one step of the long journey that these sex cells must make before they can meet and fertilize an ovum; to accomplish their task, these tiny packages of genetic information are equipped with tails for motility and enzymes to penetrate the outer membrane of the ovum when contact occurs with it
medullary cavity
The hollow area inside the diaphysis of a bone; contains soft yellow bone marrow
Cytoplasm
The internal living material of cells; fills the space between the plasma membrane and the nucleus; numerous small structures (organelles) are part of the cytoplasm along with the fluid that serves as the interior environment of the cell
Filtration
The movement of water and solutes through a membrane as a result of a pushing force (hydrostatic pressure) that is greater on one side of the membrane than the other; it always occurs down a hydrostatic pressure gradient, which means that when 2 fluids have unequal hydrostatic pressures and are separated by a membrane, water, diffusible solutes or particles will filter out of the solution that has the higher hydrostatic pressure into the one that is lower; partly responsible for moving water and small solutes from blood into the fluid spaces of the body's tissues; one of the processes responsible for urine formation in the kidney - wastes are filtered out of the blood into the kidney tubules because of a difference in hydrostatic pressure
peripheral nervous system (PNS)
The nerves connecting the brain and spinal cord to other parts of the body; term peripheral is appropriate because nerves extend to outlying or peripheral parts of the body; this system includes cranial and spinal nerves that connect the brain and spinal cord, respectively, to peripheral structures such as skin surface and the skeletal muscles; other structures in the ANS are also considered part of the PNS and they connect the brain and spinal cord to various glands in the body and to the cardiac and smooth muscles in the thorax and abdomen
Polycythemia
The number of RBCs increases beyond normal and thus increases blood viscosity which increases BP; CNS occur when oxygen levels in air decrease and the body attempts to increase its ability to attract oxygen to the blood, such as when working at high altitude
Heart Rate (HR)
The number of heartbeats (cardiac cycles) per minute; determined mostly by the natural rhythm of the heart created by the heart's own conduction system; the ANS may alter the heart's rhythm to increase or decrease HR; the sympathetic division of the ANS increases HR; neurons of the sympathetic cardiac nerve release the neurotransmitter norepinephrine (NE) which causes the SA node to increase its usual pace and thereby increase HR; the parasympathetic division of the ANS slows down HR; this happens when neurons of the vagus nerve (cranial nerve X) release acetylcholine (ACh) to decrease the part of the SA node; the balance between the antagonistic influence of sympathetic and parasympathetic signals to the heart can be shifted by a variety of factors; when blood carbon dioxide levels rise, there is a reflexive rise in HR in an attempt for the body to restore homeostasis of blood gases; a sudden drop in blood pressure triggers a reflexive increase in HR as the body attempts to restore normal blood flow out of the heart; stress-the recognition of a threat- to home static balance- can also cause a sudden increases in HR so that skeletal muscles will be ready to resist or avoid the stressor; various dysrhythmias may affect HR by disrupting the normal rhythm of the heart
Reflex
The response to impulse conduction over a reflex arc; impulse conduction by a reflex arc causes a reflex to occur; in the example reflex in the text, the nerve impulses that reach the quadriceps muscle (the effector) result in the "knee-jerk" response
Dura mater
The tough outer layer that lines the vertebral canal
Synaptic knob
Tiny bulge at the end of a terminal branch of a presynaptic neuron's axon; each one contains many small sacs or vesicles; each vesicle contains a very small quantity of a chemical compound called a neurotransmitter; when a nerve impulse arrives at the synaptic knob, neurotransmitter molecules are released from the vesicles into the synaptic cleft
Ribosomes
Tiny particles found throughout the cell; each made up of 2 tiny subunits constructed mostly of a special kind of RNA called ribosomal RNA (rRNA); some ribosomes are temporarily attached to a network of membranous canals called endoplasmic reticulum (ER); may also be free in the cytoplasm; ribosomes make enzymes and other protein compounds; their nickname is "protein factories"
Lymphatic capillaries
Tiny vessels that permit excess tissue fluid along with some other substance such as dissolved protein molecules to leave the tissue spaces; lymph flowing through the lymphatic capillaries next moves into successively larger and larger vessels sometimes called lymphatic venules and lymphatic veins; these lymphatic vessels eventually empty into 1 of 2 terminal vessels called the R lymphatic duct and the thoracic duct which return their lymph into the blood in large veins in the neck region
Golgi apparatus
Tiny, flattened sacs stacked on one another near the nucleus; little bubbles (sacs/vesicles) break off the smooth ER and carry new proteins and other compounds to the sac of the Golgi apparatus; these vesicles fuse with the Golgi sacs and allow the contents of both to mingle; the Golgi apparatus chemically processes the molecules from the ER by continuing the folding of proteins begun in the ER and combining them with other molecules to form quaternary proteins or combinations such as glycoproteins (carbohydrate/protein combos); the Golgi apparatus then packages the processed molecules into new little vesicles that pinch off and pull away from the Golgi apparatus, moving slowly outward to the plasma membrane; each vesicle fuses with the plasma membrane, opens to the outside of the cell, and releases its contents; example of a Golgi apparatus product is mucus; its nickname could be the "chemical processing and packaging center
Matrix
Tissues differ in the amount and kind of fluid material between the cells; also called extracellular matrix (ECM) to emphasize its location between cells; varies in amount and composition among the various tissues-which reflects the variety of functions among tissue types; like jelly, made up of mostly water with various interlocking fibers that thicken it; the kinds and amounts of fibers can produce a variety of matrix types - all with different functions
Tunica albuginea
Tough whitish membrane that surrounds each testis; covers the testicle and then enters the gland to form the many septa that divide it into sections or lobules
Pharynx (throat)
Tubelike structure made of muscle and lined with mucous membrane; because of its location behind the nasal cavities and mouth, it functions as part of the digestive and respiratory systems; air must pass through the pharynx on its way to the lungs, and food must pass through it on the way to the stomach; subdivided into 3 anatomical components: nasopharynx, oropharynx, and laryngopharynx; the protective lymphoid ring formed of the 3 pairs of tonsils in the pharynx help prevent infections of the respiratory and digestive tracts; the oropharynx is actively and most directly involved in the digestive process because of its important role in a specialized and coordinated type of GI tract motility involved in swallowing
Cushing syndrome
Tumors of the adrenal cortex located in the middle zone of the cortex often result in the production of abnormally large amounts of glucocorticoids; many more women than men develop Cushing syndrome; characterized by a moon face and the Buffalo hump on the back that develop because of redistribution of body fat, high blood sugar and suffer frequent infections; surgically removal of the tumor can result in dramatic improvement of the moon-face symptoms within 6 months
Inversion
Turns the ankle so that the bottom of the foot faces toward the midline of the body
Sternocleidomastoid
Two muscles that are located on the anterior surface of the neck; they originate on the sternum and then pass up and cross the neck to insert on the mastoid process of the skull; working together, they flex the head on the chest; if only one contracts, the head is both flexed and tilted to the opposite side
Universal donor blood
Type O-negative blood can be used in an emergency as donor blood; there is no danger of anti-A, anti-B or anti-Rh antibodies clumping its RBCs
Interferon (IF)
Type of small protein compound that plays an important role in producing innate immunity against viral infections; it's a cytokine produced by body cells within hours after they have been infected by a virus; the IF released from the virus-infected cells protects other cells by interfering with the ability of the virus to reproduce as it moves from cell to cell; synthetic human IF is now being "manufactured" in bacteria as a result of gene-splicing techniques and is available in quantities sufficient for clinical use; decreases the severity of many virus-related diseases, including chicken pox, measles and hep-C; also shows promise as an anticancer agent; it has been shown to be effective in treating breast, skin, and other forms of cancer
Cryptochidism
Undescended testes; readily observed by palpating of the scrotum at delivery; from the Greek words kryptikos (hidden) and orchids (testis); failure of the testes to descend may be caused by hormonal imbalances in the developing fetus or by a physical deficiency or obstruction; regardless of cause, in the cryptorchid infant the testes remain "hidden" in the abdominal cavity; because the higher temperature inside the body cavity inhibits spermatogenesis, measures must be taken to bring the testes down into the scrotum to prevent sterility; early treatment of this condition by surgery or by injection of testosterone, which stimulates the testes to descend, may result in normal testicular and sexual development
Maximum oxygen consumption
Used by exercise physiologists as a predictor of a person's capacity to do aerobic exercise; it represents the amount of oxygen taken up by the lungs. transported to the tissues, and used to do work; determined largely by hereditary factors but aerobic (endurance) training can increase it by as much as 35%
Pernicious anemia
Used to describe a deficiency of RBCs that results from a failure of the stomach lining to produce intrinsic factor-the substance that allows vitamin B12 to be absorbed from the foods we eat; because RBC production requires adequate blood levels of this vitamin, red cell numbers will decrease in the absence of intrinsic factor even if the vitamin is present in this diet; therefore, successful long-term treatment requires repeated injections of vitamin B12 to maintain normal RBC production
Sperm/seminal fluid
Used to describe the mixture of sperm cells, or sperm, produced by the testes and the secretions of the accessory, or supportive, sex glands; the accessory glands (2 seminal vesicles, a prostate gland and 2 bulboururethral (Cowper) glands) contribute more than 95 % of the secretions to the gelatinous fluid part of the semen; in addition to the production of sperm, the seminiferous tubules of the testes contribute somewhat less. than than 5% of the seminal fluid volume; usually 3-5 mL (about 1 tsp) of semen is ejacualted at one time, and each mL contains about 100 million sperm; these numbers vary considerably in healthy men, even from day to day; semen is slightly alkaline and protects sperm from the acidic environment of the female reproductive tract
anabolic steroids
Usually synthetic derivatives of the male hormone testosterone; as with naturally produced testosterone, they stimulate an increase in muscle size and strength, making them attractive to coaches and athletes who want to win their events; prolonged use of these hormones can cause serious , even life-threatening, hormonal imbalances; for this reasons, most anabolic steroids are banned from most organized sports; sports physiologists are now investigating a whole variety of chemicals, such as creating phosphate and various coenzymes that are reported to enhance strength or endurance
Vital capacity (VC)
VC=TV +IRV +ERV- expressed another way, it is the total of tidal volume, inspiratory reserve volume, and expiratory reserve volumeThe largest amount of air that we can breathe out in one expiration - by inhaling as deeply as possible, then exhaling fully; it is about 4800 mL in young men
Afferent lymphatic vessels
Vessels that bring lymph draining from connective tissue into a lymph node en route to the blood.
Tidal Volume (TV)
Volume of air moving in and out of lungs during each breath cycle; ~ 500 mL (1 pint); frequently measured in patients with lung disease or heart problems; as the tidal volume increases, the ERV and IRV decrease
Hydrocephalus
Water on the brain; one form of treatment involves surgical placement of a hollow/tube/catheter through the blocked channel so that CSF can drain into another location in the body
Depolarization
When a section of the membrane is stimulated, its NA+ channels suddenly open and NA+ ions rush in; the inside of the membrane temporarily becomes positive and the outside becomes negative
Adipose/fat tissue
When it begins to store lipids, areolar tissue can become adipose/fat tissue; numerous vesicles have formed inside the adipose cells where large quantities of triglyceride lipids accumulate; these clear lipid-storage vesicles scatter light like so many snowflakes, giving ordinary adipose tissue a whitish appearance giving it the alternate name white fat; triglycerides move into storage after a meal and out of storage as energy-producing nutrients are needed by other tissues; a special kind of adipose tissue called brown fat actually burns its fuel when the body is cold to produce heat; this heat, along with shivering muscles, helps restore homeostasis of body temperature; all types of adipose tissue also secrete hormones that help regulate metabolism and fuel storage in the body
nonsteroid hormones
Whole proteins, shorter chains of amino acids, or simply versions of single amino acids; typically work according to the second messenger mechanism; according to this concept, a nonsteroid protein hormone, such as a thyroid-stimulating hormone, acts as a "first messenger" (it delivers its chemical message from the cells of an endocrine gland to highly specific membrane receptor sites on the target cells); the interaction between a hormone and its specific receptor site on the target cell's plasma membrane is often compared with the fitting of a unique key into a lock; provides communication between endocrine glands and target organs
muscle contraction
any pulling of the muscle whether it shortens or not
concentric contraction
muscle shortens, i.e. lifting this book requires concentric contraction of the bicep muscles that flexes your elbow
gray matter
brain and spinal cord tissue consisting of cell bodies, unmyelinated cells, and dendrites; named for its characteristic gray appearance; forms the H-shaped inner core of the spinal cord
Spinal tracts
columns of white matter form the outer portion of the spinal cord and bundles of myelinated nerve fibers make up the white columns; provides two-way conduction paths to and from the brain; ascending tracts conduct impulses up the spinal cord to the brain; descending tracts conduct impulses down the spinal cord from the brain; tracts are functional organizations in that all axons composing one tract serve one general function; i.e. fibers of the spinothalamic tracts carry impulses that produce sensations of crude touch, pain, and temperature; other ascending tracts include the gracious and caneatus tracts which transmit sensations of touch and pressure up to the brain, and the anterior and posterior spinocerebellar tracts, which transmit information about muscle length to the cerebellum; descending tracts include the lateral and ventral corticospinal tracts, which carry impulses controlling many voluntary movements
organic compounds
compounds that contain carbon; generally larger and more complex than inorganic compounds
Acids
compounds that form hydrogen ions when dissolved in water
atrophy
degeneration, decline, or decrease, as from disuse
control center
determines the set point at which the variable is maintained
uremia/azotemia
excess of urea and other nitrogenous waste in the blood as a result of kidney failure; accumulates to toxic levels
Hiatal hernia
hernia resulting from the protrusion of part of the stomach through the diaphragm; sometimes, the opening in the diaphragm that permits the passage of the esophagus into the abdomen is enlarged
prostatitis
inflammation of the prostate gland
concentric lamellae
layers of calcified matrix; surrounds the central canal
fibrinogen and prothrombin
necessary for blood clotting
Acidosis
pH below 7.35
thyroid-stimulating hormone
stimulates the thyroid gland to increase secretion of thyroid hormone
hemostasis
stoppage of bleeding
hydrogen bond
weak attraction between a hydrogen atom and another atom; does not form new molecules but provides subtle forces that help a large molecule stay in place; may also help hold neighboring molecules together; helps hold proteins in their complex folded shapes and helps keep water molecules loosely joined together giving water a weak glue-like quality that helps hold the body together
Dwarfism
A condition produced by hyposecretion of growth hormone; characterized by abnormally short stature
sickle cell anemia
A genetic disease that results in the formation of limited amounts of an abnormal type of hemoglobin called sickle hemoglobin or hemoglobin S; the genetic defect produces an amino acid substitution in one of the beta polypeptide chains causing the causing the resulting HbS to be less stable and less soluble than normal hemoglobin; the defective hemoglobin forms crystals and causes the red cell to become fragile and assume a sickle (crescent) shape when the blood oxygen level is low;
Angioplasty
A procedure in which a device is inserted into a blood vessel to force open a channel for blood flow through a blocked artery; after blood has passed through the capillary beds in the myocardium, it flows into cardiac veins that empty into the cardiac sinus and then into the R atrium
Periosteum
A strong membrane of dense fibrous tissue covering a long bone everywhere except at joint surfaces where it is covered by articular cartilage; numerous blood vessels enter the bone and eventually pass through transverse canals and eventually to central canals
Segmentation
Alternating contraction of fibers of the muscularis within a single region, or segment, of the GI tract also produces a "back-and-forth" or "swishing" type of intestinal motility; assist in mixing food with digestive juices and helps continue the mechanical breakdown of larger food particles; peristalsis and segmentation can occur in an alternating sequence; when this happens, food is churned and mixed as it slowly progresses along the GI tract in close contact with the intestinal mucosa, which facilitates absorption of nutrients
Heart Rate (HR)
An increase in the rate of the heartbeat increases BP and a decrease in the rate decreases BP; but whether a change in the heart rate actually produces a similar change in BP depends on whether the stroke volume changes and by how much
Continuous ambulatory peritoneal dialysis (CAPD)
Another technique used to treat renal failure; 1-3 L of sterile dialysis fluid is introduced directly into the peritoneal cavity through an opening in the abdominal wall; peritoneal membranes in the abdominal cavity transfer waste products from the blood into the dialysis fluid, which is then drained back into a plastic container after about 2 hours; less expensive than hemodialysis and doesn't require the use of complex equipment
Making and remodeling bone
Before a baby's birth, the skeleton is composed mostly of cartilage and fibrous structures shaped like bones; these cartilage "models" transform into real bones when the cartilage is replaced with calcified bone matrix; this is an ongoing process; if needed, osteoblasts lay down organic collagen fibers; they then release a solution of inorganic calcium salts that crystallize on the fibers; the fibers reinforce the matrix to withstand twisting forces and the mineral crystals calcify to make it as "hard as bone"; the combined breaking-building actions remodels bones into their adult shapes; this process of "sculpting" allows bones to respond to stress/injury by changing size, shape and density
Receptors
Beginnings of dendrites of sensory neurons; often located far from the spinal cord (in tendons, skin or mucous membranes); text's example uses the sensory receptors that are located in the quadriceps muscle group; stretch receptors are stimulated when muscles are stretched like a tap on the patellar ligament from the rubber hammer, used by a doctor to elicit a reflex; the nerve impulse that is generated, its neurological pathway, and the "knee-jerk" are an example of the simplest form of a two-neuron arc; in the knee-jerk reflex, only sensory and motor neurons are involved; the nerve impulse generated by stimulation of the stretch receptors travel along the length of the sensory neuron's dendrite to its cell body located in the dorsal root ganglion (posterior root ganglion)
Hematocrit (Hct)
Component of the CBC provides information about the volume of RBCs in a blood sample; if whole blood is placed in a special centrifuge tube and then "spun down", the heavier formed elements will quickly settle to the bottom of the tube; during the procedure, RBCs are forced to the bottom of the tube first; the WBCs and platelets then settle out in a light-colored layer called the Buffy coat; the hematocrit test-also called packed cell volume (PCV) test -gives an estimate of the proportion of RBCs to whole blood; such info could help screen for dehydration, hemorrhaging, or other circumstances that affect the RBC ratio; normally, about 45% of the blood volume consists of RBCs
Dental caries (tooth decay)
Disease of the enamel, dentin, and cementum of teeth that results in the formation of a permanent defect called a dental cavity; the incidence of gingivitis, dental caries, and periodontitis can be reduced by good dental health practices, which include regular and thorough brushing and flossing of the teeth
Myelin disorders
Disorders of the oligodendrocytes; named so because these glial cells are involved in myelin formation; most common primary disease of the CNS is multiple sclerosis (MS); it's characterized by myelin loss and destruction accompanied by varying degrees of oligodendrocyte cell injury and death; the result is demylenization of the white matter of the CNS; hard, plaquelike lesions replace the destroyed myelin, and affected areas are invaded by inflammatory cells; as the myelin around axons is lost, nerve conduction is impaired, and weakness, incoordination, visual impairment and speech disturbances occur; disease is most common in women ages 20-40 years old; the cause of MS may be related to autoimmunity and viral infections in some individuals; typically involves relapses and is chronic; no cure yet but early diagnosis and treatment can slow/stop its progression
Renal corpuscle
Divided in 2: a)Bowman capsule-the cup-shaped top of a nephron, the hollow, sac-like Bowman capsule surrounds the glomerulus; b) Glomerulus-a network of blood capillaries tucked into the Bowman capsule, the small artery (afferent arteriole) that delivers blood to the glomerulus is larger in diameter than the efferent arteriole that drains blood from it and that it is relatively short, this explains the high BP that exists in the glomerular capillaries as it is required to filter wastes from the blood
sternoclavicular joint
Only direct point of attachment between the scapula and the clavicle; occurs between the clavicle and the sternum; very small joint;
strength training
Enhances muscle hypertrophy; it involves contracting muscles against heavy resistance; examples of common strength-training exercises are isometric exercises and weight lifting; this type of training results in increased numbers of myofilaments in each muscle fiber; although the number of muscle fibers stays the same, the increased number of myofilaments greatly increases the mass of the muscle
nervous tissue
Function is to provide rapid communication between body structures and control of body functions; consists of 2 kinds of cells: nerve cells or neurons which are the conducting units of the system, and special connecting and supporting cells called glia or neuroglia; all neurons are characterized by a cell body and 2 types of processes: one axon, which transmits a nerve impulse away from the cell body, and one or more dendrites which carry impulses toward the cell body
Albumins
Help retain water in the blood by osmosis; IV administration is sometimes used as a plasma volume expander in people with abnormally low blood volume; the injected albumin will draw about 3-4 times its volume of fluid into the blood through the process of osmosis; the result is an expansion of blood volume that can be lifesaving in cases of hemorrhage, severe burns or kidney disease
External intercostal muscles
Located between the ribs; when they contract, they enlarge the thorax by increasing the size of the cavity from front to back and from side to side; contraction of the inspiratory muscles increases the volume of the thoracic cavity, and reduces lung air pressure below atmospheric pressure, drawing air into the lungs
Aldosterone
Hormone secreted by the adrenal cortex that plays an important role in controlling the kidney tubules' reabsorption of sodium; primarily, it stimulates the tubules to reabsorb sodium at a faster rate; also increases tubular water reabsorption because "water always follows sodium" by osmosis when possible; reduces urine volume and is nicknamed "salt-and-water retaining hormone"; kidney itself is responsible for triggering aldosterone secretion, a fact that illustrates the importance of the kidney in regulating overall fluid volume and BP in the body; when blood volume and pressure drop below normal, this is sensed by cells in the JG apparatus; JG cells then release an enzyme called renin that initiates the renin-angiotensin-aldosterone system (RAAS)
Monocyte
Immune defenses (phagocytosis)
Visceral pericardium/epicardium
Inter layer of the pericardium; covers the heart the way an apple skin covers an apple
spinal cord
Lies inside the spinal column in the spinal cavity and extends from the occipital bone down to the. bottom of the first lumbar vertebra; H-shaped core of the spinal cord consists of gray matter and thus is composed mainly of dendrites and cell bodies of neurons; contains the centers for thousands and thousands of reflex arcs; the interneuron switches/transfers incoming sensory impulses to outgoing motor impulses, thereby making it possible for a reflex to occur; if an injury cuts the spinal cord all the way across, impulses can no longer travel to the brain from any part of the body located below the injury, nor can they travel from the brain down to these parts
synovial membrane
Lines the joint capsules that surround and attach the ends of articulating bones in movable joints are classified as connective tissue membranes; smooth and slick and secrete a thick, colorless lubricating fluid called synovial fluid; reduces friction between the opposing surfaces of bones in movable joints; also line the small, cushion like sacs called bursae found between many moving body parts
Pseudostratified epithelium
Lines the trachea or windpipe; each cell actually touches the gluelike basement membrane that lies underneath all epithelial tissues; although the epithelium appears to be several cell layers thick, it's not which is why it is called pseudo (false) stratified epithelium; the cilia that extend from the cells are capable of moving in unison; in doing so, the cilia moves mucus along the lining surface of the trachea, affording protection against entry of dust or foreign particles into the lungs
Lacunae
Little spaces in the hard layers of the lamellae that contain osteocytes
Respiratory control centers
Located in the brainstem and are the sites of origination of nervous impulses that stimulate respiratory muscles; influenced by input from a number of sensory receptors located in different areas of the body; these receptors can sense the need for changing the rate or depth of respirations to maintain homeostasis; certain receptors sense carbon dioxide or oxygen levels whereas others sense blood acid levels or the amount of stretch in lung tissues; the depth and rate of respiration can be influenced by many "inputs" to the brainstem's respiratory control centers from other areas of the brain or from sensory receptors located outside of the central nervous system
Chemoreceptors
Located in the carotid and aortic bodies; specialized sensory receptors that are sensitive to increases in blood carbon dioxide level and decreases in blood oxygen level; carotid body chemoreceptors are found at the point where the common carotid arteries divide; the aortic bodies are small clusters of chemosensitive cells that lie adjacent to the aortic arch near the heart; when stimulated by increasing levels of blood carbon dioxide, decreasing oxygen levels, or increasing blood acidity, these receptors send nerve impulses to the respiratory regulatory centers that in turn modify respiratory rates; the blood PCO2 level is the most powerful stimulus driving respiration
Fascia
Loose connective tissue outside the muscle organs that forms a flexible, sticky "packing material" between muscles, bones, and the skin
Hypothermia
Low body temperature; drastically affects cellular activity and normal body function;
T lymphocytes (T cells)
Lymphocytes that have undergone their 1st stage of development in the thymus gland; stem cells from the bone marrow seed the thymus, and shortly before and after birth, they develop into T cells; the newly formed T cells stream out of the thymus into the blood and migrate chiefly to the lymph nodes, where they take up residence; embedded in each T cell's cytoplasmic membrane are protein molecules shaped to fit only one specific kind of antigen molecule; the 2nd stage of T-cell development takes place when and if a T cell comes into contact with its specific antigen; if this happens, the antigen binds to the protein on the T cell's surface, changing the T cell to an activated T cell; T cells must also receive a chemical (cytokine) signal from another T cell to become activated; T-cells also produce a clone of identical cells, all able to react with the same antigen; T cells form a group of effector cells along with memory cels ; the effector T cells actively engage in immune response whereas memory T cells don't; later if more effector T cells are needed, the memory T cells can produce additional clones that include more effector T cells
Carpal tunnel syndrome
May result if swelling, or any other lesion in the carpal tunnel presses on the median nerve; since the median nerve connects to the palm and radial side (thumb side) of the hand, it is characterized by weakness, pain, and tingling in that part of the hand; the pain and tingling may also radiate to the forearm and shoulder; prolonged and severe cases may be relieved by injection of anti-inflammatory agents; a permanent cure is sometimes accomplished by surgically cutting the fibrous band called the flexor retinaculum enclosing the carpal tunnel - thus relieving pressure on the median nerve
endorphins and enkephalins
Morphine-like neurotransmitters; released at various spinal cord and brain synapses in the pain conduction pathway; these inhibit conduction of pain impulses; they're natural pain killers; research shows that endorphins increase during heavy exercise; endorphins inhibit pain, so it's no wonder that pain associated with muscle fatigue decreases when endorphins are present; pain is a warning signal that calls attention to injuries or dangerous circumstances but it's better to inhibit severe pain if it would stop us from continuing an activity that may be necessary for survival; athletes and others who exercise regularly reported an unique feeling of well-bring or euphoria associated with elevated endorphin levels
Esophagus
Muscular, mucus-lined tube that connects the pharynx with stomach; it is about 25 cm (10 in) long; serves as a dynamic passageway for food, pushing the food toward the stomach; the production of mucus by the glands in the mucosal lining lubricates the tube to permit easier passage of foodmoving toward the stomach; each end is guarded by a muscular sphincter
Passive transport process
No cellular energy is required to move substances from a high concentration to a low concentration; 4 primary passive transport processes are diffusion, osmosis, dialysis and filtration; scientists describe the movement of substances in passive systems as going "down a concentration gradient"; this means that substances in passive systems move from a region of high concentration to a region of low concentration until they reach equal proportions on both sides of the membrane
Femur
Only bone in the thigh; longest bone in the body and articulates proximally at the hip with the coral bone in a deep, cup-shaped socket called the acetabulum; distally, the femur articulates with the patella (kneecap) and the tibia (shinbone)
Complement cascade
Often when antigens that are molecules on an antigenic or foreign cell's surface combine with antibody molecules, they change the shape of the antibody molecule slightly but just enough to expose two previously hidden regions; these are called complement-binding sites; the exposure of the complement-binding sites of an antibody that is attached to an antigen on the surface of a threatening cell then permits complement proteins to initiate a series of events that kills off the cell
Bone
Primary organs of the skeletal system; lie buried beneath the muscles and other soft tissues providing a framework and support structure for the whole body; they are living organs that contain osteocytes; they can remodel themselves and help the body respond to a changing environment; contains a vital tissue (red bone marrow, the blood cell-forming tissue) that produces red blood cells and several types of white blood cells that protect the body from disease; play an important part in maintaining homeostasis of blood calcium, a vital substance required for normal nerve and muscle function; serve as a safety deposit box for calcium; when the amount of calcium increases to an above-normal level, it moves out of the blood and into the bones for storage; when blood calcium decreases to a lower than normal level, it comes out of storage and enters the blood; the balance of calcium deposits and withdrawals to and from the skeleton are regulated by a balance of hormones; cavities inside some bones also store fat;
Secretion
Process by which substances move into urine into the distal and collecting ducts from blood in the capillaries around these tubules; secretion is reabsorption in reverse; whereas reabsorption moves substances out of the of the urine into the blood, secretion moves substances about of the blood into the urine; tubular secretion serves an important function by removing or "clearing" the blood of excess potassium and hydrogen ions, certain drugs including penicillin and phenobarbital, and numerous wastes such as urea, uric acid, and creatinine; most substances that are secreted from peritubular blood enter the filtrate primarily in the proximal tubule and, to a lesser extent, the distal convoluted tubule and collecting ducts; the major exception is potassium ion, which is secreted primarily into the collecting ducts in an exchange with sodium; urine volume of potassium ions varies greatly with diet; some diuretic drugs, which stimulate the production of urine are said to be "potassium wasting" because they increase secretion of potassium into tubular fluid and thus its excretion in the urine; in the distal convoluted tubules and collecting ducts, sodium secretion is dependent on hormones also important in regulating urine volume; ammonia is secreted passively by diffusion; kidney tubule secretion plays a crucial role in maintaining the body's fluid, electrolyte, and acid-base balance
Dendrite
Processes or projections that carry impulses to the neuron cell bodies
Weak bases
Produce a H+ concentration a bit lower than pure water and have a pH value just a bit higher than 7
Auditory tubes/eustachian tubes
R and L auditory tubes open into the nasopharynx and connect the middle ears with the nasopharynx; this connection permits equalization of air pressure between the middle and the exterior ear; the lining of the auditory tubes is continuous with the lining of the nasopharynx and the middle ear so middle ear infections can develop from inflammation of the nasopharynx, like sinus infections develop from inflamed nasal mucosa
Diastole
Relaxation of the heart
Chemical equation
Representation of a chemical reaction; reactants are separated from the products by an arrow showing the "direction" of the reaction; single arrow is used for equations that occur in only 1 direction; double arrow is used for reactions that happen in "both directions" at the same time; double arrow indicates that at any instant in time, both reactants and products are present in the solution at the same time; products are separated from each other by plus signs (+)
osteons/haversian system
cellular arrangement; each circular and tubelike osteon is composed of calcified matrix arranged in multiple layers that resemble the rings of an onion
Calcitonin (CT)
Secreted by thyroid gland cells that lie outside the thyroid follicles; decreases the concentration of calcium in the blood by first acting on bone to inhabit its breakdown; with less bone being resorted, less calcium moves out of bone into blood, and, as a result, the concentration of blood decreases; an increase in calcitonin secretion quickly follows any increase in blood calcium concentration, even if it's a slight one; this causes blood calcium concentration to decrease to its normal level; helps maintain homeostasis of blood calcium; prevents hypercalcemia
atrial natriuretic hormone (ANH)
Secreted from the heart's atrial wall and has the opposite effect of aldosterone; primary atrial natriuretic peptide (ANP) hormone in humans; stimulates kidney tubules to secrete more sodium and thus lose more water; it is a "salt-and-water losing hormone", thus it increases urine volume; the body secretes ADH, aldosterone, and ANH in different amounts, depending on the homeostatic balance of body fluids at any particular moment
Synovial membrane
Secretes a slippery lubricating fluid (synovial fluid) that fills the bursa; a bursa makes it easier for a tendon to slide over a bone when the tendon's muscle shortens
Simple cuboidal epithelium
Single layer of cells that are, on average, as high as they are wide - thus exhibiting a cube shape; this tissue forms tubules or other groupings adapted for secretory activity which is why they appear to form ringlike arrangements in cross section; also form the tubules that form urine in the kidneys; in some glands, cuboidal epithelium occurs in more than one layer; such stratified columnar epithelium may be found in the sweat gland ducts
Skeletal muscle tissue
Skeletal/striated muscle is called voluntary because willed or voluntary control of skeletal muscle contractions is possible; when viewed under a microscope, it is characterized by many cross striations and many nuclei per cell; individual cells are long and threadlike and are often called fibers; attached to bones, and when contracted, produce voluntary and controlled body movements
cutaneous membrane
Skin, the primary organ of the integumentary system; one of the most important and one of the most largest and visible organs of the body; in most people, skin is about 16% of the body weight; fulfills the requirements necessary for an epithelial tissue membrane in that it has a superficial layer of epithelial cells and an underlying layer of supportive connective tissue; its structure is uniquely suited to its many functions
Scrotum
Skin-covered pouch suspended from the groin; internally it is divided by 2 sacs by a septum; each sac contains a testis, epididymis, the lower part of the vas deferens, and the beginning of the spermatic cord
Fibula
Slender, non-weight bearing and fragile bone which lies along the outer or lateral border of the leg
Gallstones
Solid clumps of material (mostly cholesterol) that form in the gallbladder of 1 in 10 Americans; some never cause problems and are called silent gallstones, whereas others produce painful symptoms or other medical complications and are called symptomatic gallstones; often form when the cholesterol concentration in bile becomes excessive, causing crystallization or precipitation to occur; stone formation is much more likely to occur if the gallbladder isn't empty regularly and chemically induces or cholesterol-laden bile remains in the gallbladder for long periods; can sometimes be treated (dissolved) over time or prevented from developing in at-risk individuals by giving oral medicine or in some cases surgery
Coccyx
Tailbone
Systemic gas exchange
The exchange of gases that occurs between blood in systemic capillaries and the body cells is called internal respiration; during internal respiration oxygenated blood enters systemic capillaries and is changed into deoxygenated blood as it flows through them; during the process of delivering oxygen, the waste product carbon dioxide is also picked up and transported to the lungs for removal from the body
Interphase
The initial growing stages of a a newly formed cell, in which a cell is busy with protein growth and other growth and maintenance functions; this initial growth period of interphase is followed by a period during which the cell prepares for possible cell division; during interphase, the cell is said to be "resting" - it is only resting from the standpoint of active cell divisions but it is active in all other aspects; during interphase but just before mitosis begins, the DNA of each chromosome makes an identical copy of itself; the cell then enters another period of interphase before it actively begins to divide
Hormones
The main regulators of metabolism, growth and development, reproduction, and many other body activities; play important roles in maintaining homeostasis - fluid and electrolyte, acid-base, and energy balances, for example; make the difference between normalcy and many kinds of abnormalities, such as dwarfism and sterility; 2 major classes of hormones - nonsteroid hormones and steroid hormones-differ in the mechanisms by which they influence target cells
Connective tissue
The most abundant and widely distributed tissue in the body; exists in more varied forms than any of the other types; found in skin, membranes, muscles, bones, nerves, and all internal organs; exists as delicate, paper-thin webs that hold internal organs together and gives them shape; also exists as strong and tough cords, rigid bones, and even in the form of a fluid-blood; functions are as varied as its structure and appearance; connects tissues to each other and forms a supporting framework for the body as a whole and its individual organs; as blood, it transports substances throughout the body; also function to defend against microbes and other invaders
Plasma
Thin watery matrix of blood; has no fibers at all (except when forming a blood clot) which allows it to remain free flowing
Membrane
Thin, sheet like structure that may have many important functions in the body; cover and protect the body surface, line body cavities, and cover the inner surfaces of the hollow organs such as the digestive, reproductive and respiratory passageways; some membranes anchor organs to each other or to bones and others cover the internal organs; in certain areas of the body, membranes secrete lubricating fluids that reduce friction during organ movements such as the beating of the heart or lung expansion and contraction; membrane lubricants also decreases friction between bones in joints; 2 major categories of membranes - epithelial membrane (composed of epithelial tissue and an underlying layer of fibrous connective tissue) and connective tissue (composed exclusively of various types of connective tissue, no epithelial cells present); 3 types of epithelial membranes: cutaneous, serous, and mucous
Phalanges
Toe bones and finger bones; same number of toe bones as finger bones; foot bones are called metatarsals and tarsals; foot only has 7 tarsal bones compared to the hand's 8 carpal bones; largest tarsal bone is the calcaneus, the heel bone
Renal pyramids
Triangular divisions of the medulla of the kidney; extensions of cortical tissue that dip down into the medulla between the renal pyramids are called renal columns
Trapezius
Triangular-shaped muscles form the line from each shoulder to the neck on its posterior surface; they have a wide line of origin extending from the base of the skull down the spinal column to the last thoracic vertebra; when contracted, the trapezius muscles help elevate the shoulders and extend the head backwards
Isotope
Two atoms that have the same atomic number but different atomic masses
Human Growth Hormone (hGH)
Used by some to keep themselves youthful or boost athletic performance; these unapproved uses can have dangerous side effects by disrupting normal hormone balances in the body
Gigantism
a condition produced by hypersecretion of growth hormone during the early years of life; child grows to giant size
Homeostasis of blood gases
When we are not moving around, we take about 12-18 breaths a minute, but when were are exercising, we take considerably more than that; our tidal volume also increases worth physical activity; the reason our respiratory rate changes is because our body attempts to maintain a high set point level of oxygen and a low set point level of carbon dioxide in our blood; when our cells use up oxygen during exercise, the draw more oxygen from the blood-reducing blood oxygen concentration below its set point; likewise, cells release more carbon dioxide into the blood during exercises-those raising the blood carbon dioxide concentration above its set point; various regulatory mechanisms respond to these changes in negative feedback loops that reverse blood gas concentrations back toward their set point values-by changing our respiratory rate and depth of breathing
Radioactive isotope
an isotope that has an unstable nucleus and that emits radiation
lamina propria
fibrous connective tissue underlying the epithelium in mucous membranes
intercostal muscles
located between the ribs
Pineal gland
secretes melatonin; small gland near the roof of the 3rd ventricle of the brain; named pineal because it resembles a pine nut; easily located in a child but becomes fibrous and encrusted with calcium deposits as a person ages; produces a number of hormones in very small amounts; sometimes called the 3rd eye because it receives and responds to sensory information from the light-sensitive ganglion cells of the eye's retina; the information regarding changing light levels is used to adjust the output of melatonin
peptide bond
strong chemical bond that joins amino acids
respiratory system
system responsible for taking in oxygen and releasing carbon dioxide using the lungs; to accomplish its functions, the respiratory system filters, warms, and humidifies the air we breathe; respiratory organ such as vocal cords and sinuses help produce speech and make smell possible
frenulum
thin membrane that attaches the tongue to the floor of the mouth; occasionally a person is born with a frenulum that is too short to allow free movement of the tongue so he/she can't enunciate words properly; tongue is divided into the blunt, rear portion called the root, a pointed tip, and a central body
Chromosomes
threadlike structures made of DNA molecules that contain the genes; each cell of the body contains a total of 46 different DNA molecules in its nucleus and a copy of a 47th DNA molecule in each of its mitochondria
Villi
tiny, finger-like structures that protrude from the wall of the intestine and project into the lumen; inside each villus lies a rich network of blood capillaries that absorb the products of carbohydrate and protein digestion (sugars and amino acids) and lymph capillaries (lacteals) that absorb fats; millions and millions of villi jut inward from the mucous lining; this large absorptive surface area allows for faster absorption of nutrients from the intestine into the blood and lymph; in addition to the millions of villi that increase surface area in the small intestine, each villus is itself covered by epithelial cells, which have a brushlike border composed of microvilli
Synapse
A junction between two nerve cells; the nerve impulse stops at the synapse, chemical signals are sent across the gap, and then a new impulse continues along the dendrites, cell body, and axon of the motor neuron; definition is the place where impulses are transmitted from one neuron (presynaptic neuron) to another (postsynaptic neuron); made up of 3 structures: a synaptic knob, a synaptic cleft, and the plasma membrane of a postsynaptic neuron
Atherosclerosis
A life-threatening blockage of arteries
Endosteum
A thin membrane that lines the medullary cavity
Universal recipient blood
Blood Type AB+ because it contains no anti-A, anti-B or anti-Rh antibodies in its plasma; therefore Type AB+ blood does not clump any donor's RBCs containing A, B, or Rh antigens
Pons
Bulges out a bit more than medulla, forming a bridge to the narrower midbrain
Myocardium
Cardiac muscle tissue that composes the wall of each heart chamber
Motor neuron/efferent neuron
Carries impulses in the opposite direction - away from the brain and spinal cord; only conduct impulses to muscle and glandular epithelial tissue
Target cell
Cell that has a receptor for a particular hormone
Abdominopelvic cavity
Combines both the abdominal cavity and the pelvic cavity because no physical partition separates them
Torso
Composed of thoracic, abdominal and pelvic areas
Pericardium
Covering of the heart; 2 layers of fibrous tissue with a small space in between them; the 2 pericardial layers slide over each other without friction when the heart beats because these are serous membranes with moist surfaces; a thin film of pericardial fluid provides lubrication between the heart and its enveloping pericardial sac
Hematopoiesis
Describes the process of blood cell formation; combined of 2 Greek words "hemato" meaning "blood" and "-poeisis" meaning " a making";
Cilia
Extremely fine, hairlike extensions on the exposed/free surfaces of cells; larger than microvilli and possess inner microtubules that support them and enable them to move; every cell has at lease one cilium; act like an insect's antenna, allowing the cell to sense its surroundings, i.e. the hairlike cilia in the taste buds can detect different chemicals by taste; some cells have hundreds of cilia capable of moving together in a wave-like fashion; by moving as a group in one direction, the cilia can propel mucus over the surfaces of cells that line the respiratory or reproductive tubes
sympathetic division
Functions as an emergency system; impulses over sympathetic fibers take control of many internal organs when we exercise strenuously and when strong emotions are elicited; when we must cope with stress of any kind, sympathetic impulses increase to many visceral effectors and rapidly produce widespread changes within our bodies; need such physiological preparation when facing a threat - we must be ready to either resist (fight) the threat or to avoid (fly from) the threat; this group of changes induced by sympathetic control is known as the fight or flight response
Heat production
Healthy survival depends on our ability to maintain a constant body temperature; a fever or elevation in body temperature of only a degree or two is almost always a sign of illness; a fall in body temperature is just as serious; the contraction of muscle fibers produces most of the heat required to maintain body temperature ; energy required to produce a muscle contraction comes from ATP; some of the energy transferred to ATP and released during a muscular contraction is used to shorten the muscle fibers; much of the energy is lost as heat during its transfer to ATP; this heat helps us maintain our body temperature at a constant level; sometimes heat from generating ATP during heavy muscle use can produce too much heat and we have to sweat or remove a layer of clothing to cool back down to our set point temperature
Fatigue
If muscle fibers are stimulated repeatedly without adequate rest periods, the strength of the muscle contraction decreases, resulting in fatigue; if repeated stimulation occurs, the strength of the contraction continues to decrease, and eventually the muscle loses its ability to contract; during exercise, the stored ATP becomes depleted; formation of more ATP results in a rapid consumption of oxygen and nutrients, often outstripping the ability of the muscle's blood supply to replenish them; when oxygen supplies run low, the muscle fibers switch to a type of energy conversion that does not require oxygen; this process produces lactic acid that may contribute to a burning sensation in muscle during exercise
Sensor
In homeostasis, a receptor that detects a stimulus.
Globulins
Include the antibodies that help protect us from infection
Corpus callosum
Inferior central band which is made up of white matter tracts
Endocarditis
Inflammation of the endocardium; if inflamed, the endocardial lining can become rough and abrasive to RBCs passing over its surface
Prothrombin time (PT)
Laboratory test that is used to regulate dosage of anticoagulant drugs; in this test, thromboplastin (a blood clotting factor) and calcium are added simultaneously to a tube of the patient's plasma and a tube containing the normal control solution, and the time required for clot formation in both tubes is determined; a patient prothrombin time in excess of the standard control value (11 to 12.5 seconds) indicates the level of anticoagulant effect caused by the administered drug; unfortunately, PT test results may vary between different clinical laboratories; variability is often caused by differing techniques or differences in the sensitivity of reagents used
Right and L pleural cavities
Lateral subdivisions of the thoracic cavity
Prostate gland
Lies just below the bladder and is shaped like a doughnut; the urethra passes through the center of the prostate before traversing the penis to end at the external urinary orifice; the prostate secretes a thin milk-colored fluid that constitutes about 30% of the total seminal fluid volume; this fraction of the ejaculate helps activate the sperm and maintain their motility
Formed elements of blood
Many different types of cells and cell fragments that are suspended in the plasma; 3 main types and several subtypes: A. Red blood cells (RBCs), or erythrocytes; B. White blood cells (WBCs) or leukocytes ,1. Granular leukocytes (have granules in their cytoplasm), a. Neutrophils, b. eosinophils, c. Basophils; 2. Agranular leukocytes (do not have granules in their cytoplasm) a. Lymphocytes, b. Monocytes; C, platelets, or thrombocytes; since RBCs, WBCs, and platelets are continually being destroyed, the body must continually make new ones to take their place at a really staggering rate: a few million RBCs are manufactured each second
Interleukins (ILs)
Many of the cytokines are proteins called ILs; appropriate name for a substance used by WBCs to communicate between cells; ILs are often involved in signaling in both innate and adaptive immune mechanisms, i.e. ILs are involved in producing a fever and in activating the cells of adaptive, specific immunity
Hyaline cartilage
Moderate amount of collagen in its gel matrix, giving it a translucent, glass-like appearance; hyaline means "glassy"; most common type of cartilage found in the body; found in the support rings of the respiratory tubes and covering the ends of bones that form joints
Glioma
Most common type of brain tumor
Neutrophils/phagocytes
Most numerous of the active WBCs; protect the body from invading microorganisms by taking them into their own cell bodies and digesting them by the process of phagocytosis
Respiratory organs
Nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi (branches), and lungs
compact bone
Outer layer of bone is hard and dense; appears solid to the naked eye; does not contain a network of open spaces
Large intestine
Only 1.5 meters (5 feet) in length; has a much larger diameter than the small intestine; forms the lower/terminal portion of the digestive tract; chyme enters the large intestine after passing through the ileocecal valve and changes to a more solid consistency of fecal matter as water and salts are reabsorbed through during its passage through the small intestine; it is this pastelike material that passes through the valve into the large intestine; the ileocecal valve opens into a pouch like area called the cecum; the opening itself is about 5-6 cm (2 in) above the beginning of the large intestine; material in the cecum flows upward to a region of the large intestine called the colon; material moves into the colon on the R side of the body-the ascending colon; the hepatic flexure/R colon flexure is the bend between the ascending colon and the transverse colon which extends across the front of the abdomen from R to L; the splenic flexure/L colic flexure marks the point where the descending colon turns downward on the L side of the abdomen; the sigmoid colon is the S-shaped segment that terminates in the rectum; the terminal portion of the rectum is called the anus
Iliopsoas
Originates from deep within the pelvis and the lower vertebrae to insert on the lesser trochanter of the femur and capsule of the hip joint; generally classified as a flexor of the thigh and an important postural muscle that stabilizes and keeps the trunk from falling over backward when standing; however, if the thigh is fixed so that it cannot move, it flexes the trunk
Osmotic balance
Osmosis moves water in a direction that results in dilution of the solution to a type of equilibrium
oxyhemoglobin (HbO2)
Oxygen-hemoglobin complex is formed by an iron (Fe) atom within each heme group attracts oxygen molecules to unite with hemoglobin; makes possible the efficient transport of 98.5% of all of the oxygen required for the body cells (1.5% is dissolved in plasma); iron (Fe) is an essential nutrient needed to give hemoglobin its oxygen-carrying ability; vitamin B12 and folate (also a B vitamin) are also among the critical nutrients needed by the red bone marrow to manufacture enough hemoglobin to maintain survival;
Elastin
Present in some tissues; its rubbery quality gives tissues the ability to stretch and rebound easily
Endotracheal intubation
Procedure where a tube is placed through the mouth, pharynx, and larynx into the trachea of surgery patients, especially if they have been given a muscle relaxant; the purpose of the tube is to ensure an open airway; to ensure that the tube enters the trachea rather than the nearby esophagus (that leads to the stomach), anatomical landmarks such as the vocal folds are used ; another landmark is using the distinct feel of the V-shaped posterior groove that is called the interarytenoid notch
Intestinal glands
Secrete the intestinal digestive juice that is rich in a variety of enzymes as well as water and ions; the pancreas excretes bicarbonate into the lumen of the duodenum to neutralize the stomach acid and also adds enzymes to digest fats, proteins, and carbohydrates that are absorbed in the intestine; smooth muscle in the wall of the small intestine contracts to produce peristalsis; segmentation activity helps mix the digestive juices with chyme and also makes absorption more efficient
Chemoreflexes
Sense and respond to increasing blood acid levels
Hemoglobin (Hb)
The additional intracellular space that becomes available in each cell when the nucleus and cytoplasmic organelles are lost is filled to capacity with an important red pigment; unique chemicals of properties of hemoglobin permit the RBC to perform several critically important functions required for maintenance of homeostasis, such as carrying oxygen and buffering blood;
Immune system
The body's overall defense system; the body's defense mechanisms protect us from disease-causing microorganisms that invade our bodies, from foreign tissue cells that may have been transplanted into our bodies, and from our own cells when they have turned cancerous; the immune system is an interactive network of many organs and many organs and billions of freely moving cells and trillions of free-floating molecules in many different areas of the body
Epiphyses
The ends of the bone; red bone marrow fills in small spaces in the spongy bone composing the epiphyses; some yellow marrow may appear as the person ages; center of ossification
cardiac output
The volume of blood pumped by one ventricle per minute; it averages about 5 L in a normal, resting adult; determined by the heart rate (HR) and stroke volume (SV); abnormally decreased CO can result in fatigue or, with a significant drop in CO, even death
biceps brachii
Two-headed muscle that serves as a primary flexor of the forearm; originates from bones of the shoulder girdle and inserts on the radius in the forearm
aqueous solution
a blend of two or more kinds of molecules with water being the solvent; forms the "internal sea" of the body
Carbohydrate
compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body when cell's bonds are broken, the energy is released and then trapped by the cell's chemistry to do work
preganglionic neurons
conduct impulses between the spinal cord and a ganglion; axon endings synapse with the dendrites or cell bodies of postganglionic neurons
Chemical reactions
interactions among molecules in which atoms regroup into new combinations; always involve energy transfers
endochondral ossification
"Formed in cartilage"; a long bone grows and ultimately becomes "ossified" from small centers within a developing bone
Conchae/turbinates
3 shelflike structures protrude into the nasal cavity on each side; the mucosa-covered conchae greatly increase the surface over which air must flow as it passes through the nasal cavity; as air moves over the conchae and through the nasal cavities, it is warmed and humidified ; this helps explain why breathing through the nose is more effective in humidifying inspired air than is breathing through the mouth
Spinal curvatures
4 curves in the spine; neck and the small of the back curve slightly inward or forward and the chest region of the spine and the lowermost portion curve in the opposite direction; a newborn baby's spine forms a continuous convex curve from top to bottom; as the baby learns to hold his/her head up, a reverse or concave curve develops in the neck; as the baby learns to stand, the lumbar region of his/her spine also becomes concave; normal curves of the spine give it enough weight to support the weight of the rest of the body; the curves also make it possible for us to balance the weight of the body so we can walk instead of crawl; the spine needs to be strong as it supports the head balanced on top of it, the ribs and internal organs that are suspended from it in the front and the hips and legs attached to it below
Conduction system
4 structures embedded in the wall of the heart specialized in generating strong impulses and conduct them rapidly to certain regions of the heart wall; they make sure that the atria and then the ventricles contract in an efficient manner; they are 1) sinoatrial node which is sometimes called the SA node or the pacemaker, 2)atrioventricular node or AV node, 3)AV bundle of bundle of His, 4)subendocardial branches also called Purkinje fibers; impulse conduction normally starts in the SA node, the pacemaker, from there, it spreads in all directions to the atria which causes the atrial fibers to contract; when impulses reach the AV node, it is triggered to relay its own impulse by way of the AV bundle and subendocardial branches to the ventricular myocardium, causing the ventricles to contract, normally a ventricular beat follows each atrial beat; various conditions such as endocarditis or MI can damage the heart's conduction system and thereby disturb its rhythmic beating; one such disturbance is the condition called heart block; impulses are blocked from getting through to the ventricles, resulting in the ventricles beating at a much slower rather than normal; a physician may treat heart block by implanting an artificial pacemaker in the heart; it's an electrical device that causes ventricular contractions at a rate fast enough to maintain an adequate circulation of blood; the heart's conduction system generates tiny electrical currents that spread through surrounding tissues and eventually to the surface of the body; this fact is of great clinical significance because these electrical signals can be picked up from the body surface and transformed into visible tracings by an electrocardiograph
Basal nuclei/basal ganglia
A few islands of gray matter within the white matter in the cerebrum; functioning is essential for producing automatic movements and postures
Ductus venosus
A continuation of the umbilical vein; serves as. shunt, allowing most of the blood returning from their placenta to bypass the immature liver of the developing fetus and empty directly into the inferior vena cava; the foramen ovals shunts blood from the R atrium directly into the L atrium and the ductus arteriosus connects the aorta and pulmonary artery; these structures allow the blood to bypass the fetus's developing lungs; at birth the baby's umbilical blood vessels and shunts must be made nonfunctional; when the newborn infant takes its first deep breaths, the cardiovascular system is subjected to increased pressure; the result is closure of the foramen ovale and rapid collapse of the umbilical blood vessels, the ductus venous and ductus arteriosus
Lung volume reduction surgery (LVRS)
A "treatment of last resort" for severe cases of emphysema; involves the removal of 20-30% of each lung; diseased tissue is generally removed from the upper/apical areas of the superior lobes; evidence from a number of large clinical trials has now shown that the LVRS procedure may benefit or at least help stabilize selected emphysema patients whose lung function continues to decline despite aggressive pulmonary rehabilitation efforts and other, more conservative forms of treatment; more than 2 million Americans, who are older than age 50 and current or former smokers, have emphysema- a major cause of disability and death in the U.S.; emphysema is one of a number of conditions classified as a chronic obstructive pulmonary disease (COPD); emphysema is characterized by the trapping of air in alveoli of the lung, which causes them to rupture and fuse to other alveoli; although lung damage caused by emphysema is irreversible, in some cases the disease may be halted or its progression slowed by LVRS; in the end stages of this chronic disease, breathing becomes labored as the lungs fill with large, irregular spaces resulting from the enlargement and rupture of many alveoli; the LVRS procedure removes part of the diseased lung tissue and increases available space in the pleural cavities; asa result, the diaphragm and other respiratory muscles can more effectively move air into and out of the remaining lung tissue, thereby improving pulmonary function and making breathing easier; LVRS may reduce the need for lung transplantation procedures and augment the effectiveness of such supporting medical treatments as nutritional supplementation and exercise training in the treatment of selected late-stage emphysema patients; newer and less invasive techniques involving smaller incisions and specialized video equipment inserted into the thoracic cavity (video-assisted thoracic surgery) are now being used for many LVRS procedures; as a result, the relatively long hospital stays and home recovery periods previously required after more traditional open-chest surgery have been shortened
sleep apnea
A condition that results in brief but often frequent pauses in breathing during sleep; it is often caused by enlarged tonsil tissue and may necessitate tonsillectomy
Calyx
A division of the renal pelvis (the papilla of a pyramid opens into each calyx)
Blood doping/blood boosting
A few weeks before an important event, an athlete has some blood drawn; the RBCs in this sample are separated and frozen; just before competition, the RBCs are thawed and injected back into the athlete; the increased hematocrit that results slightly improves the oxygen-carrying capacity of the blood, which theoretically improves performance; while the impact on performance is slight, the dangers to health and survival; in addition to blood transfusions, injection of substances such as hormones that stimulate hematopoiesis (blood cell production) to increase RBC levels; in an attempt to improve athletic performance , it has been condemned by leading authorities in the areas of sport medicine and by athletics organization around the world
Flagella
A flagellum is a single projection extending from the cell surface; flagella are structurally similar to cilia but much longer; can move like cilia; the cylinder of microtubules inside the flagellum moves in a way that whips the flagellum around like a propeller, pushing the cell forward, i.e., in a human the only example of a flagellum is the "tail" of the male sperm - the wiggling makes it possible for sperm to "swim" or move toward the ovum after they are deposited in the female reproductive tract
Sickle cell trait
A form of the disease that shows up in a person who inherits only one defective gene that develops only a small amount of HbS; usually have no symptoms at all; however, in some stressful or high-exertion situations, a person with sickle cell trait could become ill; if 2 defective genes are inherited (one from each parent), then more HbS is produced and a much more severe condition called called sickle cell disease develops; in addition to RBC suckling and rupture , high levels of HbS may cause reduction in blood flow; abnormal blood clotting; and in episodes of "crisis", severe pooling of red cells, particularly in the spleen, causing sudden death; treatment is primarily supportive because no effective anti-suckling drugs are currently available; however, patient education, early diagnosis, preventive measures to reduce dehydration and infection, and limited use of blood transfusions to treat episodes of crisis are improving survival rates; sickle cell anemia is found almost entirely in those of black African descent, and in the U.S., nearly 1 in every 600 African-American newborns is affected with sickle cell trait/disease; if hemoglobin and RBC numbers fall below the normal levels, as they do in any type of anemia, it starts an unhealthy chain reaction: less hemoglobin, less oxygen transported to cells, slower use of nutrients by cells, less energy produced by cells, decreased cellular functions; an anemic's chief complaint is that he/she is "so tired all the time"
Ganglion
A group of nerve-cell bodies located in the PNS; the one shown in the text is located near the spinal cord; each dorsal root ganglion contains hundreds of sensory neuron cell body; the axon of the sensory neuron travels from the cell body in the dorsal root ganglion and ends near the dendrites of another neuron located in the gray matter of the spinal cord; a microscopic space separates the axon ending of one neuron from the dendrites of another neuron
Organ
A group of several different kinds of tissues arranged in a way that allow them to act as an unit to perform a special function
Cerebrovascular accident (CVA)
A hemorrhage from or cessation of blood flow through cerebral blood vessels; when this happens, the victim can no longer voluntarily move the parts of the body on the side to opposite to the side on which the CVA occurred; nontechnical language - the person has suffered a stroke;
Diaphysis (shaft)
A hollow tube made of hard, compact bone, hence a rigid and strong structure light enough in weight to permit easy movement
Follicle-stimulating hormone (FSH)
A hormone released from the anterior pituitary that stimulates the ovarian follicle
Glucagon
A hormone secreted by alpha cells ; accelerates glycogenesis; increases blood glucose concentration; several hormones increase glucose concentration, including glucocorticoids, growth hormone and glucagon
Insulin
A hormone secreted by beta cells; decreases blood glucose concentration; the only hormone that can decrease blood sugar levels; decreases blood glucose by accelerating its movement out of the blood, through cell membranes and into cells; as glucose enters the cells at a faster rate, the cells increase glucose metabolism
Frontal plane/also referred to as a Coronal plane
A lengthwise plane running from side to side; divides the body or any of its parts into anterior and posterior (front and back) portions
Solvent
A liquid substance capable of dissolving other substances
Gluconeogenesis
A process in liver cells that converts amino acids or glycerol to glucose
Hypothesis
A reasonable guess based on previous informal observations or on previously tested explanations
Inflammatory response
A set of nonspecific responses that often occur in the body; bacteria cause tissue damage that triggers the release of mediators from any of a variety of immune cells; many of these factors produce the characteristic signs of inflammation: heat, redness, pain, and swelling; these signs of inflammation are caused by increased blood flow and vascular permeability in the affected region; such changes help phagocytic WBCs and beneficial proteins reach the general area and enter the affected tissue; systemic inflammation can occur when the inflammation mediators - cytokines and other chemical signals- trigger responses that occur on a body-wide basis; a systemic (body-wide) inflammatory response may be manifested by a fever - the elevated temperature of a low to moderate fever may facilitate some immune reactions and may also inhibit the reproduction of some bacteria; a class of enzymes in blood plasma called complement can trigger a cascade of chemical reactions that literally punch holes in abnormal cells and regulate other immune mechanisms; complement can be triggered by both innate, nonspecific mechanisms and by specific immune mechanisms
Epididymis
A single, very tightly coiled tube about 6 meters (20 ft) in length; a comma-shaped structure that lies along the top and behind the testes inside the scrotum; sperm mature and develop their ability to move/swim as they're temporarily stored in the epididymis; specialized cells lining the epididymis secrete nutrients for developing sperm and also remove substantial amounts of excess testicular fluid as the developing sex cells enter and eventually pass through the lumen of this highly coiled tube
Trachea (windpipe)
A tube about 11 cm (4.5 in) long and 2.5 cm (1 in) wide; extends from the larynx in the neck to the bronchi in the chest cavity; provides part of the open passageway through which air can reach the lungs from the outside; lined by the typical respiratory mucosa, which contains numerous mucus-producing glands and is covered by cilia; the glands help produce part of the blanket of mucus that is continually moved by the beating cilia in one direction-upward and toward the pharynx- as part of the ciliary escalator mechanism; trachea serves a protective function by production and movement of mucus important in trapping and eliminating airborne contaminants; trachea's framework is made of an almost noncollapsible material-15 or 20 C-shaped rings of cartilage placed one above the other with only a little soft tissue between them; incomplete cartilage rings permit easy swallowing by allowing the esophagus (food tube) to stretch within the narrow space in the neck between the trachea and the vertebrae; despite the structural safeguard, blockage of the trachea sometimes occurs; a tumor or an infection may enlarge the lymph nodes of the neck so much that they may squeeze the trachea shut, or a person may aspirate (breathe in) a piece of food or something else that blocks the windpipe; because air has no other way to get to the lungs, complete tracheal obstruction causes death in a matter of minutes; suffocation from all causes kills more than 4000 people every year and is the 5th major cause of accidental death in the U.S.
Digestive tract
A tube that extends from the mouth to the anus; the hollow space within the tube is called the lumen;the wall of the tube is made up of 4 layers from the inside coat to the outside of the tube and are named as follows: mucosa/mucous membrane, submucosa, muscularis, and serosa; although the same 4 tissue coats form every organ of the alimentary tract, their structure varies from organ to organ
Leukocytosis
Abnormally high WBC count (more than 10,000 WBCs of blood); much more common problem than leukopenia and almost always accompanies bacterial infections; also seen in many forms of blood cancer which are often diagnosed when tremendous increases in WBC numbers are detected in blood tests
Sliding filament model
According to this model, during contraction, the thick and thin myofilaments in a muscle fiber first attach to one another by forming crossbridges that then act as levers to ratchet or pull the myofilaments past each other; the connecting bridges between the myofilaments form only if calcium is present; during the relaxed state, calcium ions are stored within the smooth ER in the muscle cell; when a nerve signal stimulates the muscle fiber, the ER releases calcium into the cytoplasm; there, the calcium ions bind to the blocking proteins in thin filaments and permit actin to react with myosin; the myosin heads connect to actin, pull, release, and then pull again; this ratcheting of myosin heads thus pulls the thin filaments toward the center of the sarcomere- producing the muscle contraction; the contraction process of a muscle cell also requires energy which is supplied by glucose and other nutrients; the energy must be transferred by the ATP molecules; oxygen is required to transfer energy to ATP and make it available to myosin heads, so it's not surprising that many muscles have high oxygen requirements; to supplement the oxygen carried to muscle fibers by the hemoglobin of blood, muscle fibers contain myoglobin
B lymphocytes (B cells)
All lymphocytes arise from primitive cells in the bone marrow called stem cells and go through 2 stages of development; the 1st stage of B-cell development - transformation of stem cells into immature B cells-occurs in the liver and bone marrow before birth but only in the bone marrow in adults; since this process was 1st discovered in a bird organ called the bursa, these cells were named B cells; immature B cells are small lymphocytes that have synthesized and inserted into their cytoplasmic membranes numerous molecules of one kind of specific antibody; after they mature, B cells eventually leave the tissue where they were formed; Each mature, but inactive, B cell carries a different type of antibody; the various B cells then enter the blood and are transported to the lymph nodes; the 2nd stage of B-cell development changes a mature, inactive B cell into an activated B cell; this change only occurs if an inactive B cell comes in contact with certain nonself or abnormal molecules-antigens-whose shape fits into the shape of the B cell's surface antibody molecules; if this happens, the antigens lock onto the antibodies and, by so doing, change the inactive B cell into an activated B cell; B-cell activation also requires a chemical signal (cytokine) from another immune cell-a type of T cell; then the activated B cell, by dividing rapidly and repeatedly, develops into groups or clones of many identical cells-all having the same type of antibody; function indirectly to produce humoral immunity-resistance to disease organisms produced by the actions of antibodies binding to specific antigens while circulating in body fluids; activated B cells develop into plasma cells
Tunica intima
An inner layer of endothelial cells lines arteries and veins; actually a single layer of squamous epithelial cells called endothelium that lines the inner surface of the entire cardiovascular system; also sometimes include a thin layer of elastic fibrous tissue; veins have an unique structural feature not present in arteries; a vein's tunica intimacies equipped with pockets that act as one-way valves which protect the backflow of blood-thus keeping blood flowing in one direction, back toward the heart; these valves allow veins to act as supplemental pumps that help venous return of blood to the heart; occasional activity of skeletal muscles surrounding the veins of the body create pressure on blood that drives these venous pumps; this explains why stretching, walking, and other activities helps improve blood circulation and prevent the formation of thrombi (abnormal clots) in the veins; capillaries cannot be sene because they are microscopic; the most important structural feature is their extreme thinness-only one layer of flat, endothelial cells composes the capillary membrane; the capillary wall is only composed of the tunica intima; substances such as glucose, oxygen, and wastes can quickly pass through it on their way to or from cells
Stress
An internal state or condition which is the result of extreme stimuli acting on the body; the normal adrenal cortex responds to the condition of stress by quickly increasing the secretion of glucocorticoids; when avoiding/resisting a threat, the increased blood glucose can help improve our skeletal muscle function - reduced inflammation keeps one less swollen, therefore more mobile which will help deal with the threat; decreased immunity helps focus all resources on the more immediate threat and immunity is restored after a threatening event so that it can deal with any damage; frequent/prolonged stress responses could cause metabolic problems by disturbing normal mechanisms keeping blood glucose and stored fats in balance; chronic stress can increase susceptibility to cancer and infections by reducing immunity; prolonging anti-inflammatory effects may cause constriction of blood vessels which may raise our blood pressure
Tendons
Anchor muscles firmly to bones and are made of dense fibrous, connective tissue that extends from the muscle "wrappers"; shaped like heavy cords or broad sheets so they have great strength; do not tear or pull away from bone easily
Mitochondria
Another kind of organelle in all cells; they are so tiny that a lineup of 15,000 or more of them would fill a space only about an inch long; 2 membranous sacs, one inside the other, compose a single mitochondrion; the inner membrane forms folds that look like miniature incomplete partitions; within the mitochondrion's fragile membranes, complex, energy-converting chemical reactions occur continuously; since these reactions supply most of the power for cellular work, mitochondria are nicknamed the cell's "power plants"; enzymes (molecules that promote specific chemical reactions) which are found in mitochondrial membranes and inner substance, break down products of glucose and other nutrients to release energy; mitochondrion uses this released energy to "recharge" ATP (adenosine triphosphate) molecules, the "batteries " needed for cellular work; this energy-transferring process is called cellular respiration; each mitochondrion has its own tiny DNA molecule, sometimes called a mitochondrial chromosome, which contains info for building and running the mitochondrion.
The aging kidney
As with other body organs, the kidneys undergo both age-related structural changes and decreasing functional capacity; adults older than 35 years of age gradually lose functional nephron units, and kidney weight actually decreases; by approx. 80-85 years of age, most individuals will have experienced a 30% reduction in total kidney mass; despite this, most of these people still exhibit normal kidney function because older persons generally have a lower overall lean body mass and therefore a reduced production of waste that must be excreted from the body; however, any stress on the remaining functional nephrons can produce almost immediate symptoms of kidney failure; marginal kidney function in old age may make it difficult to excrete drugs that are easily cleared from the blood of younger persons, and dosages of many medications have to be adjusted accordingly to older patients
Transfer RNA (tRNA)
Assist the process by bringing specific amino acids in to "dock" at each codon along the mRNA strand; a codon is a series of 3 nucleotide bases, a "triplet", that acts as a code representing a specific amino acid; each gene is coded in the mRNA is made up of a series of codons that tell the cell the sequence of amino acids to string together to form a protein strand; each tRNA includes an anticodon segment at one end, which is a complementary sequence of 3 bases that allow the tRNA to recognize the particular codon for the type of amino acid carried by that tRNA molecule; the strand of amino acids formed during translation folds on itself and may even combine with another strand to form a complete protein molecule; the specific, complex shape of each type of protein molecule allows the molecule to perform specific functions in the cell
Bone's matrix fibers
Encrusted with minerals crystals to give it the characteristics of reinforced concrete
Complete blood count (CBC)
Battery of tests used to measure the the amounts or levels of many blood constituents and is often ordered as a routine part of the physical exam; measuring the numbers of circulating RBCs per unit of blood volume is a valuable part of the CBC; values listed in CBC results as "normal" will vary slightly among laboratories and reference texts; normal deviations from average ranges often occur with age differences, level of hydration, altitude of residence, and other variables; RBC counts were done with a hemocytomer, a microscopic slide with a counting grid etched on it; the current practice is to use a faster, more accurate automated blood cell counter
Filtration
Beginning of urine formation; goes in continually in the renal corpuscles; blood flowing through the glomeruli exerts pressure and this glomerular BP is high enough to push water and dissolved substances out of the glomeruli into the Bowman capsule; if the glomerular BP drops below a certain level, filtration and urine formation stop, i.e.e hemorrhage may cause a precipitous drop in BP followed by kidney failure; glomerular filtration normally occurs at the rate of 125 mL per minute; as a result, about 180 L (nearly 50 gallons) of glomerular filtrate is produced by the kidneys every day; no one excretes even close to that amount because most of the fluid returns to the blood by reabsorption
Blood flows through the heart
Blood enters the R atrium through the superior vena cava and inferior vena cava; the R heart pump receives oxygen-poor blood from the veins; after entering the R atrium, it is pumped through the R AV and. enters the R ventricle; when the ventricles contract, blood in the R ventricle is pumped through the pulmonary SL valve into the pulmonary artery and eventually to the lungs where oxygen is added and carbon dioxide is lost; blood rich in oxygen returns to the L atrium of the heart through 4 pulmonary veins; it then passes through the L AV into the L ventricle; when the L ventricle contracts, blood is forced through the aortic SL valve into the aorta and is distributed to the body as a whole; the 2 sides of the heart actually pump blood through 2 separate "circulations" and function as 2 separate pumps; the pulmonary circulation involves movement of blood from the R ventricle to the lungs; the systemic circulation involves movement of blood from the L ventricle throughout the body as a whole
Systemic circulation
Blood flows from the L ventricle fo the heart through blood vessels to all parts of the body and back to the R atrium of the heart; blood is pumped out of the L ventricle to the aorta and then flows into arteries that carry it to the tissues and organs; within each structure, blood moves from arteries to arterioles to capillaries; next, blood flows out of each organ's capillary beds by way of its venules and then its veins to drain eventually into the inferior or superior vena cavae; these 2 great veins return venous blood to the R atrium of the heart; at that point the blood is short of coming full circle back to its starting point in the L ventricle
Bone marrow transplants
Bone marrow may be damaged by toxic chemicals or by high-dose x-ray and chemotherapy treatments; it can also be destroyed by diseases such as leukemia; regardless of cause, if the bone marrow is severely damaged, a bone marrow transplant can be lifesaving; in this procedure, a needle is used to extract red marrow from the coral or hipbone of a compatible donor who is under anesthesia; the donated bone marrow is then processed and introduced into the recipient intravenously; transplantation may also involve infusion of blood-forming stem cells harvested from the individual being treated, from a compatible donor, or from umbilical cord blood; if the recipient's immune system does not reject the new tissue or stem cells (always a danger in transplant procedures), a new colony of healthy tissue may become established in the marrow; as a result, destroyed or damaged myeloid tissue will be replaced and begin again to produce normal functioning cells
Phagocytes
Bone-marrow-derived cells that carry on phagocytosis, or ingestion and digestion of foreign cells or particles; antibody molecules that bind to and coat certain foreign particles help macrophages function effectively; they serve as "flags" that alert the macrophage to the presence of foreign material, infectious bacteria, or cellular debris; they also help bind the phagocyte to the foreign material so that it can be engulfed more effectively; 2 important types are neutrophils and monocytes; these blood phagocytes migrate out of the blood and into the tissues in response to an infection; the neutrophils are functional but short lived in the tissues; the pus found at some infection sites is mostly dead neutrophils; once in the tissues, monocytes develop into phagocytic cells called macrophages; most macrophages then "wander" through the tissues to engulf bacteria wherever they find them
Thorax/chest
Bony cage Formed by 12 pairs of ribs, the sternum (breastbone) and the thoracic vertebrae; each of the 12 pairs of ribs is attached posteriorly to a vertebra; all of the ribs, but the last 2 pairs, are also attached to the sternum so they have both posterior and anterior anchors; the 1st 7 pairs of ribs (sometimes called the true ribs) are attached to the sternum by costal cartilage; the 8th, 9th, and 10th pairs of ribs are attached to the cartilage of the 7th ribs and are sometimes called false ribs; the last 2 pairs of ribs are not attached to any costal cartilage so they seem to float in front, hence the name floating ribs
Combined ABO-Rh system
Both systems are used in combination to identify a person's blood type; knowing one's blood type can be lifesaving in a medical emergency or during surgery, when a blood transfusion may be needed to maintain the total blood volume; harmful effects or even death can result from a blood transfusion reaction if the donor's RBCs become agglutinated by antibodies in the recipient's plasma; in a normal clinical setting, all blood intended for transfusion is not only matched carefully to the blood of the recipient for ABO and Rh compatibility but also tested further in a process called cross matching for a variety of so-called "minor antigens" that may also cause certain types of transfusion reactions
Metaphase
By the time this has begun, the nuclear envelope and nucleolus have disappeared; the chromosomes have aligned themselves across the center of the cell; the centrioles have also migrated to opposite ends of the cell and spindle fibers are attached to each chromatid
Axis
C2; has a pointed dens (meaning "tooth") that extends up into the curve of the atlas's anterior arch to act as pivot around which the atlas (and the skull) can swivel left and right
tooth
Can be divided in 3 main parts: crown, neck, and root; center of the tooth contains a pulp cavity that consists of connective tissue, blood and lymphatic vessels and sensory nerves; in humans, a set of 20 teeth called deciduous or baby teeth erupt between 6-30 months of age; although the time frame may vary somewhat, these teeth are generally lost between 6-13 years old; the first permanent teeth to appear, called the first or "6-year" molars erupt before all of the baby teeth are lost; in the deciduous set of 20 teeth, there are no premolars and only 2 pairs of molars in each jaw; when a young adult is between 17-24 years of age, the deciduous teeth have all been shed and completely replaced with a full set of 32 permanent teeth; the 3rd molars or "wisdom teeth" are the last permanent teeth to appear
sensory neuron/afferent neuron
Carries impulses to the spinal cord and brain from all parts of the body
Prostate cancer
Causes hypertrophy of the gland and restricted or obstructed urine flow caused by malignant tumor growth; in addition to surgery, cancerous prostatic growths may also be treated using systemic chemotherapy, cryotherapy (freezing) of prostatic tissue, microwave (heat) therapy, hormonal therapy, inserting radioactive "seeds" directly into the tumor, and the use of various types of external-beam radiation
Dorsal Body Cavity
Cavities that are located in a dorsal position in the body; examples include cranial and spinal cavities
Cell life cycle
Cell reproduction is 1 part of the cell's life cycle; it involves the division of the cell into 2 genetically identical daughter cells; cell reproduction requires division of the nucleus and division of the cytoplasm;
Composition of cells
Cells contain cytoplasm; is derived from the Greek combining form cyto and denotes a relationship to a cell; each cell is surrounded by a plasma membrane; this membrane separates the cell contents from interstitial fluid which bathes every cell in the body; numerous specialized structures called organelles are contained within the cytoplasm; a small, circular body called the nucleus is also inside the cell
juxtaglomerular (JG) apparatus
Cells function in blood volume and BP regulation; when BP is low, which often occurs when blood plasma volume is low, these JG cells secrete an enzyme that triggers a system to restore normal blood volume and pressures
T lymphocyte
Cellular immune response; destroys virally infected cels and cancer cells
Parkinson disease (PD)
Chronic nervous disorder resulting from a deficiency of the neurotransmitter dopamine in the basal nuclei of the cerebrum; group of signs associated with this disorder is a syndrome called Parkinsonism; characterized by rigidity and trembling of the head and extremities, a forward tilt of the trunk, and a shuffling manner of walking; all of these characteristics result from a lack of dopamine, leading to misinformation in the brain that normally prevents the skeletal muscles from being overstimulated; dopamine injection into the blood and dopamine pills are not effective because they can't cross the blood-brain barrier; a breakthrough came when the drug levodopa or L-dopa was found to increase the dopamine levels in afflicted patients; neurons use L-dopa, which can cross the blood-brain barrier, to make dopamine; this solution doesn't always have the desired effect in some patients so there have been a couple of alternatives such as surgical grafting of normal dopamine-secreting cells into the brains of individuals with PD, also an artificial implant that gives electrical stimulation to the basal nuclei, causing them to produce more dopamine
pulmonary circulation
Circuit that helps the blood reach the L ventricle and start the process all over again; venous blood moves from the R atrium to the R ventricle and then to the pulmonary artery to lung arterioles and capillaries; the exchange of gases between the blood and air takes place, converting the deep crimson color typical of venous blood to the scarlet color of arterial blood; this oxygenated blood then flows through lung venules into 4 pulmonary veins and returns to the L atrium of the heart; from the L atrium, it enters the L ventricle from which it will again be pumped throughout the body in systemic circulation
Fetal circulation
Circulation before birth differs because the fetus must secure oxygen and nutrients from maternal blood instead of its own lungs and digestive organs; blood vessels must carry the fetal. blood to the placenta where the exchange occurs and then return it to the fetal body; umbilical cord composed of 2 small umbilical arteries and a single, much larger umbilical vein accomplish this purpose; the umbilical vein carries oxygenated blood and the umbilical artery carries oxygen-poor blood
Ion pumps
Complex membrane component; an example of a protein structure in the cell membrane called a carrier; the ion pump uses energy from ATP to actively move ions across cell membranes against their concentration gradients; pump suggests that active transport moves a substance in an uphill direction; an ion pump is specific to one type of ion, i.e. sodium pumps move sodium ions; some ion pumps are "coupled" to one another so that 2 or more different substances may be moved through the cell membrane at once; some ion pumps are coupled with other specific carriers that transport glucose, amino acids, and other substances; water can only move passively by osmosis so there is no transporter pump
Mucosal immunity
Complex system of defense distinct from the systemic (internal) immune system; includes both innate and adaptive mechanisms that are found within the mucous barriers of the body: digestive tract, urinary/reproductive tracts, respiratory tract, exocrine ducts, conjunctiva, middle ear, and so one; immune cells that make up the mucosal immune system are located mainly in or near mucosal-associated lymphoid tissue (MALT); main functions involve preventing pathogens from colonizing the mucous surfaces of the body, preventing the accidental absorption of antigens from outside the body, and blocking inappropriate or intense responses of the systemic immune system to these external antigens; understanding the mucosal immune system and its cooperation with the internal immune system promises to reveal new strategies of immunization; i.e. researchers have found that immunizing through the bloodstream activates only the internal B cells and T cells; thus, a pathogen would have to actually enter our internal environment before this type of specific immunity could protect us; immunization of the mucosal lymphocytes can activate both mucosal and systemic lymphocytes, providing a more thorough type of protection; another advantage is that it is easier to administer to patients than immunizations injected under the skin or into the bloodstream; i.e.e immunization can be delivered by nasal sprays or drops
RNA
Composed of nucleotide subunits made up of a sugar, a phosphate and 1 out of 4 bases; RNA subunits contain a different sugar and base component; in RNA nucleotide subunits, uracil is substituted for thymine; these are all single-stranded molecules, but there are some short double-stranded RNA molecules in existence; Some genes contain info that is needed to build regulatory types of RNA molecules; regulatory RNA molecules act as functional molecules that affect some of the chemical processes in a cell, i.e. rRNA forms most of the ribosome's protein-synthesizing structure and other RNA molecules that serve as temporary working copies of genetic code; the actual process of protein synthesis occurs at ribosomes in the cytoplasm and on ER; RNA (another nucleic acid) copies the genetic info from the nucleus and carries it to the cytoplasm; RNA can also be an end product formed in the nucleus using the DNA code and transported out to the cytoplasm, where it regulates various functions of the cell
Brainstem
Composed of the medulla oblongata, pons and the midbrain; all 3 parts function as two-way conduction paths; sensory fibers conduct impulses up from the spinal cord to other parts of the brain, and motor fibers conduct impulses down from the brain to the spinal cord; many important reflex centers lie in the brainstem; the vital centers (cardiac, respiratory, and vasomotor centers) are located in the medulla; impulses from these centers control heartbeat, respiration, and blood vessel diameter (which is important in regulating blood pressure)
Upper respiratory tract
Composed of the nose, pharynx and larynx; an upper respiratory infection (URI) is often used to describe a "head cold" as the symptoms tend to involve the sinuses, nasal cavity, pharynx, and/or larynx
serous membrane
Composed of two distinct layers of tissue - the epithelial sheet is a thin layer of simple squamous epithelium and the connective tissue layer forms a very thin, gluelike basement membrane that holds and supports the epithelial cells; is a single continuous sheet of tissue covering 2 different surfaces; the 1st type of serous membrane layer lines body cavities and the 2nd type covers the organs in those cavities; secrete a thin, watery fluid that helps reduce friction and serves as a lubricant when organs rub against one another and against the walls of the cavities that contain them
cardiac muscle
Composes the bulk of the heart; fibers are cylindrical, branch frequently and then recombine into a continuous mass of interconnected tissue; have cross striations; also have unique dark bands called intercalated discs; demonstrates the principle of "structure fitting function" as the interconnected nature of cardiac muscle fibers helps the tissue to contract as an unit and increases the efficiency of the heart muscle in pumping blood
Bases (alkaline)
Compounds that reduce the concentration of hydrogen ions in a solution.
pelvic girdle/hip girdle
Connects the legs to the trunk; consists of 2 large coral bones, one on each side of the pelvis, attached inferiorly to the sacrum of the vertebral column; this ringlike attachment of bones provides strong support for the torso and connects the lower extremities to the axial skeleton
simple squamous epithelium
Consists of a single layer of very thin and irregularly shaped cells; because of the thin structure, substances can readily pass through its cells, making transport its special function, i.e. absorption of oxygen into the blood takes place through the simple squamous epithelium that forms the tiny air sacs in the lungs
Genitals/genitalia (male)
Consists of the penis and scrotum
dense fibrous connective tissue
Consists of thick bundles of strong, white collagen fibers that are packed closely together; a few fiber-producing cells are scattered among the bundles; regular dense fibrous connective tissue has its collagen fiber bundles arranged in parallel rows; this type of connective tissue makes up tendons - the strong straps that connect muscle to bone, it provides great strength and flexibility, but it cannot stretch; irregular dense fibrous connective tissue has its collagen arranged in a chaotic swirl of tangled bundles, this type of tissue forms the tough sheets in the deepest layer of the skin, it forms a tough, flexible support to the epithelial superficial layer of the skin, although the swirled pattern allows the skin to stretch a little, over stretching the skin often causes tears in the irregular fibrous tissue called stretch marks
isometric contraction
Contraction of a skeletal muscle does not always produce movement; sometimes, it increases the tension within a muscle but does not change the length of a muscle; isometric contraction occurs when the muscle contracts and no movement results; isometric comes from Greek words that means "equal measure"; in other words, a muscle's length during an isometric contraction and during relaxation is about equal; although muscles do not shorten (and thus produce no movement) during isometric contractions, tension within them increases; because of this, repeated isometric contractions make muscles grow larger and stronger; an example of isometric exercise is pushing against a wall or other immovable project; although no movement occurs and the muscle does not shorten, its external tension increases dramatically
T lymphocytes/cells
Critical to the functioning of the immune system
DNA replication
DNA molecules can make identical copies of themselves; before a cell divides to form 2 new cells, each DNA molecule in its nucleus forms another DNA molecule just like itself; when not replicating, the DNA molecule is shaped like a tightly coiled double helix; as it begins replication, short segments uncoil, and the 2 strands of the molecule pull apart between their base pairs; the separated strands contain unpaired basis; each unpaired base attracts its complementary base (in the nucleoplasm) and binds to it; these steps are repeated over and over throughout the length of the DNA molecule, so each half of a DNA molecule becomes a whole DNA molecule identical to the original DNA molecule; after DNA replication is complete, the cell continues to grow until it is ready for mitosis
Respiratory medicine
Danish physician Christian Bohr left a legacy of achievement in science in more ways than one; his son Niels Bohr (creator of the Bohr model of the atom (p.26) and his grandson Aage Bohr both won Nobel Prizes in science, as did his student, August Krogh; his contributions to understanding respiration have left a lasting mark on respiratory physiology and medicine - resulting in 3 Nobel Prize nominations of his own; Bohr's most famous discovery was the fact that a decrease in plasma pH or an increase in PCO2 will decrease hemoglobin's binding affinity with oxygen; called the Bohr effect, this explains how Hb easily gives up its oxygen in very active tissues like muscles during exercise-where an increase in CO2 and the accompanying acidity reflects the amount of cellular work and thus an increased use of oxygen
mucocutaneous junction
Describes the transitional area that serves as a point of "fusion" where skin and mucous membranes meet; these junctions lack accessory organs; generally moistened by mucous glands within the body orifices or openings where these junctions are located, i.e. eyelids, lips, nasal openings, vulva, and anus
Zygomaticus
Elevates the corners of the mouth and lips and has been called the smiling muscle
Abdominopelvic quadrants
Easier to locate organs; they are R upper/superior quadrant; the R lower/inferior quadrant, the L upper/superior quadrant, and the L lower/inferior quadrant; midsagittal and transverse planes pass through the navel (umbilicus) and divide the abdominopelvic cavity into the 4 quadrants; this method is often used by doctors as it is useful for locating the origin of pain or describing the location of a tumor or other abnormality
mucous membranes
Epithelial membranes that contain both an epithelial layer and a fibrous connective tissue layer; these membranes line body surfaces opening directly to the exterior of the body, i.e. those lining the respiratory, digestive, urinary, and reproductive tracts; the epithelial component varies depending on its location and function; in most cases, the cell composition is either stratified squamous or simple columnar epithelial; a tough-abrasion resistant stratified squamous epithelium is found in the esophagus, w/o the protection of a tough, epithelial lining, coarse, ingested food may cause injury to the esophageal wall when swallowed and may result in irritation or even infection and hemorrhage; a thin layer of simple columnar epithelium lines the walls of the lower segments of the digestive tract, it is well suited to the primary function of nutrient and water absorption
ABO system
Every person's blood is either - Type A, Type B, Type AB or Type O; about 41% of Americans have Type A blood, the A stands for a certain type of antigens in the plasma membrane of your RBCs that you were born with; if you are born with type A antigen, your body doesn't form antibodies to react with it (you have no anti-A antibodies) but it does contain anti-B antibodies which are just a part of the body's genetic makeup; in type A blood the RBCs contain type A antigen and the plasma contains anti-B antibodies; similarly, in type B blood, the RBCs contains type B antigen and the plasma contains anti-A antibodies; in Type AB blood, the RBC contain both A and B antigens and the plasma has neither anti-A or anti-B antibodies; the opposite is true of type B blood; its RBCs contain neither type A nor B antigens and its plasma contains both anti-A and anti-B antibodies
Sulci
Grooves forming the cerebrum; the deepest sulci are called fissures; the longitudinal fissure divides the cerebrum into right or left halves/hemispheres; the halves are almost separate structures except for the corpus callosum; 2 deep sulci subdivide each cerebral hemisphere into 4 major lobes and each lobe into numerous convolutions; the lobes are named for the bones that lie over them: frontal lobe, parietal lobe, temporal lobe, and the occipital lobe
gastroesophageal reflux disease (GERD)
Heartburn and acid indigestion are often used to describe the symptoms experienced by more than 60 million Americans each month; backward flow of stomach acid up into the esophagus causes these symptoms which typically include burning and pressure behind the breastbone; in its simplest form, it produces mild symptoms that occur only infrequently (twice a week or less); in these case, avoiding problem foods or beverages, stopping smoking, or losing weight if if needed may solve the problem; additional treatment with OTC antacids or acid-blocking medications may be used; more severe and frequent episodes of GERD can trigger asthma attacks, cause severe chest pain which can mimic heart attack symptoms, result in bleeding, or promote a stricture/narrowing or chronic irritation of the esophagus; in these cases, more powerful inhibitors of stomach acid production may be added to the treatment prescribed; as a last resort, a surgical procedure called fundoplication is performed to strengthen the sphincter - it involves wrapping a layer of the upper stomach wallaround the sphincter and terminal esophagus to lessen the possibility of acid reflux; if GERD is left untreated serious pathological (precancerous) changes in the esophageal lining - a condition called Barrett esophagus
Lymphocytes
Help protect us against infections but differently than phagocytosis; function in the immune mechanism, the complex process that makes us immune to infectious diseases; B lymphocytes (B cells) develop within several lymphoid organs of the body; they secrete plasma proteins called antibodies that attach to specific antigen molecules related to bacteria, viruses, chemical toxins, or other foreign substances; active B lymphocytes (plasma cells) are formed in unusually large numbers in a type of bone marrow cancer called multiple myeloma; other lymphocytes (T cells) mature in the thymus; T cells do not secrete antibodies but instead protect us by directly attacking bacteria, virus-infected cells, or cancer cells
Erythropoietin (EPO)
Hormone secreted by the kidney; during hypoxia, when there is a deficiency of oxygen in the body, EPO is released into the bloodstream where it travels to the red bone marrow, where it stimulates the production of additional RBCs which then increase the ability of the blood to absorb and transport oxygen to oxygen-starved tissues; EPO is sometimes used as a drug (i.e. Procrit) to treat anemia caused by critical illness; EPO is sometimes abused by athletes attempting to improve their athletic performance by boosting hematocrit- which increases the oxygen-carrying capacity of their blood; kidney disease can cause anemia to reducing the body's ability to produce EPO when needed
Anti-diuretic hormone (ADH)
Hormone secreted from the posterior pituitary gland; decreases the amount of urine by making collecting ducts permeable to water; if no ADH is present, the tubules are practically impermeable to water, so little or no water is reabsorbed from them; described as the "water-retaining hormone" or the "urine-decreasing hormone"; when filtrate moves down the collecting ducts, the action of ADH allows osmosis of water to equilibrate with the hypertonic interstitial fluid of the medulla-thus removing more water from the filtrate than would otherwise be possible; maintaining a hypertonic medulla allows ADH to have a greater effect in concentrating urine, thereby conserving the body's valuable water
Splenectomy
If the spleen is damaged and bleeding, its surgical removal may be required to stop the loss of blood and ensure survival
humoral immunity/antibody mediated immunity
In general, antibodies produce these by changing the antigens in a way that prevents them from harming the body; to do this, an antibody must first bind to its specific antigen; this forms an antigen-antibody complex; the antigen-antibody complex then acts in one or more ways to make the antigen, or the cell on which it is present, harmless, i.e. if the antigen is a toxin, the toxin is neutralized or made non-poisonous by becoming part of an antigen-antibody complex, or, if antigens are molecules in the surface membranes of threatening cells, when antibodies combine with them, the resulting antigen-antibody complexes may agglutinate (make them stick together in clumps) the enemy cells, then macrophages or other phagocytes can rapidly destroy them by ingesting and digesting large numbers of them at one time
Spleen
Largest lymphoid organ in the whole body; located high in the ULQ of the abdomen lateral to the stomach; although the spleen is protected by the lower ribs, it can be injured by abdominal trauma; very large network of reservoir veins and may contain more than 500 mL (about 1 pint) of blood; serves as a reservoir for blood that can be returned to cardiovascular system when needed; after entering the spleen, blood flows through white, pulp-like accumulations of lymphocytes; as blood flows through the white pulp, the spleen removes by mechanical and biological filtration many bacteria and other debris; the spleen also destroys worn out RBCs which often fall apart when passing through the spleen's meshwork, and salvages the iron found in hemoglobin for future use; the white pulp of the spleen also serves as a reservoir for monocytes, which can quickly leave the spleen to help repair damaged tissue anywhere in the body during an emergency; other organs can also perform these functions if the spleen if it needs to be surgically removed
Stomach
Lies in the upper part of the abdominal cavity just under the diaphragm; serves as a pouch that food enters after it has been chewed, swallowed, and passed through the esophagus; 3 divisions of the stomach are the fundus, body, and pylorus; upper R border of the stomach is called the lesser curvature and the lower L border is called the greater curvature; looks small when it is empty but expands considerably after a large meal; when felling stuffed, it means that your stomach was so full of food that it occupied more space than usual and pushed up against the diaphragm making it harder for the diaphragm to contract and move downward in order for you to take a deep breath; there are 3 layers of smooth muscle in the stomach wall; the muscle fibers that. run lengthwise, around, and obliquely make the stomach one of the strongest internal organs-well able enough to break up food into tiny particles and mix them thoroughly with gastric juice to form chyme; stomach muscle contractions result in peristalsis, which propels food down the digestive tract; mucous membrane lines the stomach, forming the mucosa; it contains thousands of microscopic gastric glands that also secrete a chemical called intrinsic factor that protects vitamin B12 and saves it for its later absorption in the distal small intestine; some individuals may require B12 injections after having had some stomach surgeries; when the stomach is empty, its mucous lining lies in folds called rugae; after food has entered the stomach by passing through the muscular LES at the lower end of the esophagus, the digestive process continues
Artificial kidney/hemodialysis
Mechanical device that uses the principle of dialysis to remove/separate waste products from the blood; in the event of kidney failure, the process called hemodialysis can provide a reprieve from death; during hemodialysis, a semipermeable membrane is used to separate large particles such as blood cells from small ones such as urea and wastes; blood from the radial artery passes through a porous cellophane tube that is housed in a tank like container; the tube is surrounded by a bath (dialysis solution) containing varying concentrations of electrolytes and other chemicals; the pores in the membrane are small and allow only very small molecules, such as urea, to escape into the surrounding fluid; larger molecules and blood cells can't escape and are returned through the tube to reenter the patient via a wrist or leg vein; by constantly replacing the bath solution, levels of waste materials can be kept at low levels; as a result, wastes such as urea in the blood rapidly pass into the surrounding wash solution; for a patient with complete kidney failure, 2-3 treatments a week are required
Ciliary escalator
Mechanism involving the cleansing layer of mucus containing inhaled contaminants moves upward to the pharynx from the lower portions of the bronchial tree on the millions of cilia that beat/move in only one direction; cigarette smoke and other irritants are detected by the cilia which beat rapidly in response - an attempt to clear out the contaminants more efficiently; prolonged exposure to cigarette smoke increases production of mucus and eventually paralyzes cilia which causes accumulations of contaminated mucus to build up and remain in the respiratory passageways for longer periods of time which results in a smoker's cough, the body's attempt to clear these large quantities of contaminated mucus
Plasma Membrane
Membrane that encloses the cytoplasm and forms the outer boundary of the cell; incredibly delicate structure; only 7 nanometers or 3/10,000,000 of an inch thick; has a precise orderly structure - phospholipids form a fluid frame for the plasma membrane; cholesterol is another component which helps stabilize the phospholipid molecules to prevent breakage of the plasma membrane; although it seems fragile, the plasma membrane is strong enough to keep the cell whole and intact; serves as a well-guarded gateway between the fluid inside the cell and the fluid around it; there are certain substances that can flow through by transporter channels and carriers but it bars the passage of other substances; also serves as a communication device - certain molecules bind to certain certain receptor proteins; plasma membrane also identifies a cell as being part of 1 particular individual; some of the surface proteins serve as positive identification tags because they only occur in the cells of that person - practical application is tissue typing; carbohydrate chains attached to the surface of cells play a role in the identification of cell types; another function of membrane proteins is as transporters that move various substances across the membrane; selectively permeable because it permits the passage of certain substances but not others; it has specific channels and carriers to allow diffusion of specific kinds of molecules; this is a necessary property if the cell is to permit some substances, like nutrients, to gain entrance to the cell but excluding others.
Renal tubule
Microscopic tube in the kidney where urine is formed after filtration; subdivided in to 4 segments: a)proximal convoluted tubule (PCT) - the first segment of a renal tubule; the PCT is called proximal because it lies in nearest the tubule's origin from the Bowman capsule, and it is called convoluted because it has several bends; b)Nephron loop (Henle loop) - the extension of the proximal tubule; consists of a straight descending limb, a hairpin turn and a straight ascending limb; c)distal convoluted tubule (DCT) - the part of the tubule distal to the ascending limb of the nephron loop; the DCT is the extension of the ascending limb; d)collecting duct (CD) - a straight part of a renal tubule; distal tubules of several nephrons join to form a single collecting duct
type 2 diabetes mellitus
Most cases result from some decrease in insulin and an abnormality of the insulin receptors, preventing the normal effects of insulin on its target cells thus also raising blood glucose levels
Skeletal variations
Most male skeletons have larger bones with more distinct bumps and other markings resulting partially from the difference in muscle tension on bones - the more tension on bone, the bigger and denser the bone gets at the points of muscle attachment; the most obvious structural difference is in the pelvis (meaning "basin"); a woman's pelvis is more rounded to accommodate housing the fetus and a wide opening allowing for the fetus to pass through during the birth process; age differences; environmental factors, such as nutrition and load-bearing/mechanical stress
Lymphocytes
Most numerous cells of the immune system; responsible for antibody production and other adaptive immune mechanisms; circulate in the body's fluids; several million strong; patrol the body, searching out any enemy cells that may have entered or threatening virus-infected cells and cancer cells; developing and reserve lymphocytes densely populate the body's widely scattered lymph nodes and its other lymphoid tissues, especially the thymus gland in the chest and the spleen and liver in the abdomen; 2 major types: B cells and T cells
Enhancing muscle strength
Most obvious and effective way of increasing skeletal muscle strength is by strength training - regularly pulling against heavy resistance; the maximal amount of muscular strength once can achieve is determined mainly by genetics but there are a number of chemical enhancements that have been tried to improve strength; an early fad was the overuse of vitamin supplements; although moderate vitamin supplementation will ensure adequate intake of vitamins necessary for good muscle function, overuse may lead to hypervitaminosis and possibly serious consequences
loose fibrous connective tissue (areolar)
Most widely distributed of all connective tissue types; it is the "glue" that helps keep the organs of the body together; it consists of webs of fibers and of a variety of cells embedded in a loose matrix of soft, sticky gel; some of the fibers are made of collagen, and some are stretchy fibers made of rubbery elastin proteins; these elastic fibers help tissues return to a shorter length after having been stretched, as in the loose tissue beneath the skin; mainly areolar tissue that makes up the fascia of the body
Autonomic neurons
Motor neurons that make up the ANS; the dendrites and cell bodies of some autonomic neurons are located in the gray matter of the spinal cord or brain stem
Rotation
Movement around a longitudinal axis, i.e. rotating your head and neck by moving skull from side to side as in shaking your head "no"
Reabsorption
Movement of substances out of the renal tubules into the blood capillaries located around the tubules (peritubular capillaries); water, glucose, and other nutrients as well as sodium and other ions, are substances that are reabsorbed; begins in the proximal convoluted tubules and continues in the nephron loop, distal convoluted tubules, and collecting ducts; nearly 90% of the 180 L of water that leaves the body each day by glomerular filtration returns to the blood by proximal tubule reabsorption; smaller amounts of water also are reabsorbed in the nephron loops, distal tubules, and collecting ducts; for the most part, sodium ions are actively transported back into blood from the tubular fluid in all segments of the kidney tubule except the collecting ducts; sodium reabsorption in the nephron loop is a special case; the nephron loop and its surrounding peritubular capillaries dip far into the medulla and back up in what is called countercurrent flow; this countercurrent flow - flow in opposite directions- of filtrate back up the nephron loop permits transport of large amounts of sodium and chloride into the interstitial fluid of the medulla; this makes the medulla very salty (hypertonic); the countercurrent flow of blood in the peritubular capillaries surrounding the nephron loop fails to remove all of the excess sodium and chloride; together, these countercurrent mechanisms maintain hypertonic concentrations in the medulla; by maintaining a hypertonic medulla, the kidney is able to concentrate the urine by reabsorbing more water than otherwise possible; the amount of sodium reabsorbed depends largely on the body's intake; in general the amount of sodium intake, the less the amount reabsorbed and the greater the amount excreted in the urine; also, the less sodium intake, the greater the reabsorption from kidney tubules and the less excreted in the urine; chloride ions passively move into blood because they carry a negative electrical charge; the positively charged sodium ions that have been reabsorbed and moved into the blood "attract" the negatively charged chloride ions from the tubule fluid into the peritubular capillaries; al of the filtered glucose is normally reabsorbed from the proximal tubules into peritubular capillary blood; none of this valuable nutrient is wasted by being lost in the urine; sometimes, not all the glucose in the tubule filtrate is recovered by the blood, i.e. in diabetes mellitus, if blood glucose concentration increases above a certain level, called the renal threshold, the tubular filtrate then contains more glucose than kidney tubule cels can reabsorb; there are not enough sodium-glucose transporters to handle the excess glucose immediately; some of the glucose therefore remains behind in the urine; glucose on the urine-glycosuria-is a well known sign of DM; the transport maximum - the largest amount of any substance that can be reabsorbed at one time- is determined mainly by the number of available transporters of that substance; the transport maximum of any substance helps determine the renal threshold - the amount of substance in the blood above which the kidney removes the excess substance from the blood
Motility
Movement of the GI wall is required to physically break down large chunks of food into smaller bits and to move it along the tract
Muscle tissue
Movement specialists of the body; attached firmly to bones; as muscles contract and shorten, they pull on bones and move them; have a higher degree of contractility (ability to shorten or contract) than any other tissue cells); can also maintain contraction to provide stability and even body heat; unfortunately, injured muscle cells are slow to heal and are often replaced by fibrous scar tissue if injured
inspiration (inhalation)
Moves air into the lungs; occurs when the chest cavity enlarges; as the thorax enlarges, the lungs expand with it, and air rushes into them and down into the alveoli; important law of physics - the volume and pressure of a gas are inversely proportional which means that when the volume of a gas goes up, as lung volume goes up when we expand the thorax, then the pressure goes down, thus air pressure in the lungs decreases during inspiration; when air pressure in the lungs is less than atmospheric air pressure, air rushes down its pressure gradient into the lungs; muscles that increase the volume of the thorax are classified as inspiratory muscles and include the diaphragm and the external intercostal muscles
expiration (exhalation)
Moves air out of the lungs; ordinarily a passive process that begins when the inspiratory muscles relax and return to their resting length; the thoracic cavity returns to its smaller volume; the elastic nature of thoracic and lung tissue also causes these organs to "recoil" and decrease in size; because volume and pressure are inversely proportional , the decrease in lung volume causes an increase in lung air pressure; as the lung air pressure rises above atmospheric air pressure, air flows down its pressure gradient and outward through the respiratory passageways
Adduction
Moving a part towards the midline, such as bringing your arms down to your sides from an elevated position
Motor neuron
Muscle fibers stimulated by a nerve fiber; before a skeletal muscle can contract and pull on a bone to move it, the muscle must first be stimulated by nerve impulses
Movement
Muscles move bones by pulling on them; because the length of a skeletal muscle becomes shorter as its fibers contract, the bones to which the muscle attaches move closer together; as a rule, only the insertion bone moves; a muscle's insertion bone moves towards its origin bone; it's important to remember that muscles can also produce tension as they extend; this occurs when muscles lengthen under tension, as the muscle insertion is pulled by a load away from the origin; voluntary muscle movement is smooth and free of jerks and tremors because skeletal muscles work as a team, not individually; several muscles contract while others relax to produce almost any movement imaginable
Complement
Name to describe a group of protein enzymes normally present in an inactive state in blood; these proteins may be activated by several triggers, including exposure of complement-binding sites on antibodies when they attach to antigens; the result is formation of highly specialized protein molecules that target foreign cells for destruction; the process is a rapid-fire cascade or sequence of events called the complement cascade; the end result of the process is that doughnut-shaped protein rings are formed and literally bore holes in the foreign cell; the tiny holes allow sodium to rapidly diffuse into the cell; water follows, through the process of osmosis; the cell literally bursts as the internal osmotic pressure increases; these also serve other roles in the immune system, such as attracting immune cells t of site of infection, activating immune cells, marking foreign cells for destruction, and permeability of blood vessels; also play a vital role in producing the inflammatory response
Neck of a tooth
Narrow portion that joins the crown of the tooth to the root; surrounded by the pink gingiva or gum tissue
Lingual tonsils
Near the base of the tongue
choroid plexus
Network of brain capillaries
Benign prostatic hypertrophy (BPH)
Noncancerous condition; common problem in older men; condition characterized by an enlargement or hypertrophy of the prostate gland; that the urethra passes through the. center of the prostate after exiting from the bladder is a matter of consideration clinical significance in this condition; as the prostate enlarges, it squeezes the urethra, frequently closing it so completely that urination becomes very difficult or even impossible; in some cases, drugs (Avodart, Flomax, others) may be used to improve urine flow and reduce symptoms of BPH; surgical removal of part or all of the gland, a procedure called prostatectomy is also a treatment option
Osteoporosis
One of the most common and serious of all bone diseases; characterized by excessive loss of calcified matrix and collagenous fibers from bone; a dangerous pathological condition resulting in bone degeneration, increased susceptibility to "spontaneous fractures", and pathological curvature of the spine; treatments may include drug therapy and dietary supplements of calcium and vitamin D to replace deficiencies or offset intestinal malabsorption; some of the effects can be prevented by exercising as a young adult to strengthen bone and maintain a diet sufficient in calcium
bronchial tree
One way to picture the thousands of air passages that make up the lungs is to think of an upside-down tree: the trachea is the main trunk of the tree, the R bronchus (tube leading into the R lung) and the L bronchus (tube leading into the L lung) are the tree's first branches, or primary bronchi; in each lung, they branch into smaller secondary bronchi whose walls are kept open by rings of cartilage for air passage; these bronchi divide into smaller and smaller tubes, ultimately branching into tiny tubes whose walls contain only smooth muscle; these very small passageways are called bronchioles; the bronchioles subdivide into microscopic tubes called alveolar ducts, which resemble the main stem of a bunch of grapes; each alveolar duct ends in small alveolar sacs, each of which resembles a cluster of grapes, and the wall of each alveolar sac is made up of numerous alveoli, each of which resembles a single, hollow grape
Transport of oxygen
Only very limited amounts of oxygen can be dissolved in the blood; to combine with hemoglobin, oxygen' must first diffuse into the RBCs to form oxyhemoglobin; hemoglobin molecules are large proteins that contain 4 iron-containing heme components, each of which is capable of combining with an oxygen molecule; oxygen associates with hemoglobin rapidly-so rapidly that about 97% of the blood's hemoglobin has united with oxygen an become "oxygenated blood" by the time it leaves the pulmonary capillaries to return to the heart; oxygen travels in two forms: 1) as dissolved O2 in the plasma and (2) asa combination of O2 and hemoglobin (oxyhemoglobin); of these 2 forms of transport, oxyhemoglobin carries the vast majority of the total oxygen transported by the blood
Role of other body systems in movement
Other structures such as bones and joints must function along with them; most skeletal muscles cause movements by pulling on bones across movable joints; the respiratory, circulatory, nervous, muscular and skeletal systems all play essential roles in producing normal movements; each part of the body is one of many components in a large, interactive system that maintains homeostasis; the normal function of one part depends on the normal function of the other parts, i.e. a person may have a nervous system disorder that shuts off impulses to certain skeletal muscles, resulting in paralysis
Hypothalamus
Production of ADH and oxytocin take place in the hypothalamus; 2 groups of secretory neurons in the hypothalamus synthesize the posterior pituitary hormones, which then pass down along axons into the pituitary gland; release of ADH and oxytocin into the blood is controlled by nervous stimulation; also produces substances called releasing hormones (RH) and inhibiting hormones (IH) which are produced int the hypothalamus and then released directly into a unique blood capillary system; this system carries the hormones to the anterior pituitary gland, where they stimulate or inhibit the release of anterior pituitary hormones into the general circulation; the combined nervous and endocrine functions of the hypothalamus allow the nervous system to influence many endocrine functions; therefore the hypothalamus plays a dominant role in the regulation of many body functions related to homeostasis such as body temperature, appetite, and thirst
Apoptosis
Programmed cell death which makes space for newer cells; "cell suicide"; when this process doesn't occur normally, the cell may remain and cause overgrowth of the tissue, possibly producing a tumor
Specific immunity
Protective mechanisms that confer very specific protection against certain types of threatening microorganisms or other toxic materials; includes a long-term protective function called immune Emory which allows the immune system to effectively stop a 2nd attack by the same specific pathogen; often called adaptive immunity because it is able to adapt to newly encountered "enemies"; when the body is first attacked by particular bacteria or viruses, disease symptoms may occur as the body fights to destroy the threatening organism; if the body is exposed a 2nd time to the same threatening organism, no serious symptoms occur because the organism is destroyed quickly - the person is said to be immune to that particular organism; immunity is said to be specific because protection against one type of disease-causing microbe does not protect the body against others; specific immune responses are slow but have memory - the ability to produce a stronger, faster response to repeated exposure to the same antigen; classified as either "natural" or "artificial" depending on how the body is exposed to the harmful agent; may be active or passive: active immunity occurs when an individual's own immune system responds to an agent that produces an immune response, whether that response was naturally or artificially encountered; passive immunity results when immunity to a disease that has developed in another individual or animal is transferred to an individual who was not previously immune; active immunity generally lasts longer than passive immunity but passive immunity, although temporary, provides immediate protection
Skull
Protects the brain; consists of 8 bones that form the cranium; 14 bones that form the face, and 6 tiny bones that make up the middle ear
Middle abdominopelvic regions of the quadrant
R and L lumbar regions and the umbilical region lie below an imaginary line across the abdomen at the level of the 9th rib cartilage and above an imaginary line across the abdomen at the top of the hip bones
Small intestine
Roughly 7 meters (20 ft) long; it is noticeably smaller in diameter than the large intestine so its name is still appropriate; in the order in which food passes through the different sections, they are the duodenum, jejunum and ileum; it must be coiled into many small loops to accommodate such a long tube in a relatively short abdominal cavity; most of the chemical digestion occurs in the duodenum which is C-shaped and curves around the head of the pancreas; the acid chyme enters the bulb of the duodenum from the stomach and this are a is the site of frequent ulceration; the middle third of the duodenum contains the openings of ducts that empty pancreatic digestive juice and bile from the liver into the small intestine; the 2 openings are located at the minor duodenal papilla and major duodenal papilla; occasionally, a gallstone blocks ducts that drain through the major duodenal papilla, causing symptoms such as severe pain, jaundice, and digestive problems; nearly all the digestion and absorption of the digestive system occurs in the small intestine; mucous lining of the small intestine contains thousands of microscopic glands
hepatic portal circulation
Route of blood flow to and from the liver; portal means "doorway" and refers to a systemic circulatory route that is a. doorway to a second set of systemic tissues; veins from the spleen, stomach, pancreas, gallbladder, and intestines do not pour their blood directly into the inferior vena cava; blood flow from these organs is detoured to the liver by means of the hepatic portal vein; the blood then passes through the regular venous return pathway to the heart; blood leaves the liver by way of the hepatic veins which drain into the inferior vena cava; most of the blood flows from arteries to arterioles to capillaries to venules to veins and back to the heart; blood flow that is directed to the hepatic portal circulation does not follow this direct route; diverted venous blood is sent to a second capillary bed in the liver; the hepatic portal vein is located between 2 capillary beds-one in the digestive organs and the other in the liver; once blood exits from the liver capillary beds, it returns to the systemic blood pathway returning to the R atrium of the heart; the detour of venous blood through a 2nd capillary bed in the liver before its return to the heart serves valuable purposes such as storing excess glucose as glycogen which means blood leaving the liver has a lower blood glucose concentration that blood entering the liver; liver cells also remove and identify various poisonous substances that might be present in the blood; the hepatic portal circulation brings any new toxins absorbed from food directly to the liver where they can be detoxified
Glands
Secretory cuboidal cells usually function in tubes or clusters of secretory cells; can be classified as exocrine (release secretions through a duct) or as endocrine (release secretion directly by diffusion into the bloodstream); examples include saliva, digestive juices, sweat and hormones such as those secreted by the pituitary or thyroid glands;
prepuce (foreskin)
Sensitive skin of the distal end of the penis is folded doubly to form a loose-fitting retractable collar around the glans; if the foreskin fits too tightly about the glans, a circumcision, or surgical removal of the foreskin after birth is usually performed to prevent irritation; most circumcisions are "elective" and are performed at the discretion of the parents for religious or cultural reasons
Diaphragm
Separates the thoracic and abdominal cavities change the size and shape of the chest during breathing; as a result, air is moved into or out of the lungs
infant respiratory distress syndrome (IRDS)
Serious, life-threatening condition that often affects prematurely born infants or those who weight less than 5 lb at birth; leading cause of death among premature infants in the U.S., claiming more than 5000 premature babies each year; the disease, characterized by a ack of surfactant in the alveolar air sacs, affects 50,000 babies annually; the ability of the body to manufacture surfactant is not fully developed until shortly before birth-38 weeks after conception; in newborn infants who are unable to manufacture surfactant, many air sacs collapse during expiration because of the increased surface tension; the effort required to reinflate these collapsed alveoli is much greater than that needed to reinflate normal alveoli with adequate surfactant; the baby soon develops labored breathing, and symptoms of respiratory distress appears shortly after birth; in the past, treatment of IRDS was limited to keeping the alveoli open so that delivery and exchange of oxygen and carbon dioxide could occur; to accomplish this, a tube was inserted into the respiratory tract, and oxygen-rich air was delivered under sufficient pressure to keep the alveoli from collapsing at the end of expiration; a newer treatment involves delivering air under pressure and applying prepared surfactant directly into the baby's airways by means of a tube
pleura
Serous membrane around each lung in the thoracic cavity
Pleura
Serous membrane that covers the outer. surface of each lung and lines the inner surface of the rib cage; extensive, thin, moist, slippery membrane which lines a large, closed cavity of the body and covers the organs within it, much like the peritoneum or pericardium; the parietal pleura lines the walls of the thoracic cavity; the visceral pleura covers the lungs, and the intrapleural space lies beneath the 2 pleural membranes; normally the intrapleural space contains just enough serous fluid to make both portions of the pleura moist and slippery and able to glide easily over each other as the lungs expand and deflate with each breath
Thymus (Thymus Gland)
Small lymphoid tissue organ located in the mediastinum, extending upward in the midline of the neck; composed of lymphocytes I an meshlike framework of reticular fibers; largest at puberty and even then weighs only about 35-40 grams; plays a central and critical role in the body's vital immunity mechanism; it is a source of lymphocytes before birth and is then important in the maturation of a type of lymphocyte that then leaves the thymus and circulates to the spleen, tonsils, lymph nodes, and other lymphoid organs; appears to complete much of its work in childhood, reaching its maximum size at puberty; by age 60, the lymphoid tissue is about 1/2 its maximum and is virtually gone by around age 80
Organelles
Small structures that make up much of the cytoplasm; name means "little organs" because they function for the cell just as organs function for the body; more than a generation ago, most organelles were unknown but now we know of may types; organelles are so small that they're invisible even when magnified 1000 times by a light microscope; electron microscopes finally brought them into view.
steroid hormones
Small, lipid-soluble steroid hormones like estrogen do not occur using the second messenger system; since they are lipid soluble, steroid hormones can pass intact directly through the plasma membrane of the target cell; once inside the cell, they pass through the cytoplasm and enter the nucleus where they bind with a receptor to form a hormone-receptor complex; this complex acts on DNA, which ultimately causes the formation of a new protein in the cytoplasm that produces specific effects in the target cell, i.e. estrogen might effect breast development in an adolescent female; the responses are typically slow compared to responses triggered by nonsteroid hormones; they may also trigger membrane receptors to produce a variety of secondary effects; these usually appear more rapidly than primary steroid effects.
Microglia
Smaller than astrocytes; usually remain stationary but in cases of inflamed or degenerating brain tissue, they enlarge, move about, and act as microbe-eating scavengers; they surround the microbes, draw them into their cytoplasm and digest them; they also help clean up cell damage resulting from injury or disease; this important cellular process is phagocytosis
sublingual glands
Smallest of the main salivary glands; lie in front of the submandibular glands, under the mucous membrane covering the floor of the mouth; each sublingual gland opens via 10-15 ducts into the floor of the mouth; produce only a mucous type of saliva
dialysis
Some solutes move across a selectively permeable membrane by diffusion and other solutes do not; results in an uneven distribution of various solutes; often used as a medical procedure in which blood is pumped through membranous tubing bathed in a solution that mimics normal body fluids; since the small waste molecules typically removed by the kidney diffuse into the bath solution, this "cleans" the blood of the waste because the larger proteins in the blood cannot diffuse; another strategy involves pumping the bath solution into the fluid space of the abdominopelvic cavity to accept the blood's wastes by dialysis; after a while, the "dirty" solution is pumped back out of the body; these procedures can be used when the kidney isn't functioning efficiently
Glottis
Space between the vocal cords
Sinuses
Spaces/cavities within some of the cranial bones; 4 pairs of them (those within the frontal, maxillary, sphenoid and ethmoid bones) have openings into the nose and thus are referred to as paranasal sinuses; air-filled sinuses are necessary to make the skull light enough for the neck to hold the head upright; sinuses can give trouble when the mucous membrane that lines them becomes inflamed, swollen, and painful
Genes
Specific segment of base pairs on a chromosome; although the types of base pairs are the same, the order or sequence is not always the same; this is important because it is the sequence of base pairs in each gene of each chromosome that determines the genetic code; most genes direct the synthesis of at least one kind of protein molecule; each protein can function as an enzyme, a structural component of a cell, or a specific hormone; it could also combine with other protein molecules, carbohydrates, or liquids to form any number of large, complex molecules; the enzymes and other functional molecules produced by protein synthesis facilitate and regulate cellular chemical formations that drive all the functions of cells and the human body; Genetic code contained in segments of the DNA molecules; determines the structure and function of the all cells; this can be transmitted to generations of cells and eventually to offspring
Removal of kidney stones using ultrasound
Statistics suggest that approx. 1/1000 adults in the U.S. suffers from kidney stones, or renal calculi, at some point in his/her life; although symptoms of excruciating pain are common, many kidney stones are small enough to pass out of the urinary system spontaneously; if this is possible, no therapy is required other than treatment for pain and antibiotics if the calculi are associated with infection; larger stones may obstruct the flow of urine and are much more serious and difficult to treat; until recently, only traditional surgical procedures were effective in removing relatively large stones; in addition to the usual risks associated with a surgical procedure, surgical removal of kidney stones required rather extensive hospital and home recovery periods, lasting 6 weeks or more; a technique that uses ultrasound waves to break up the stones is called lithotripsy, without making an incision
Adrenocorticotropic hormone (ACTH)
Stimulates the adrenal cortex to increase in size and to secrete larger amounts of its hormones, especially larger amounts of cortisol (hydrocortisone)
Gonadotropin-releasing hormone (GnRH)
Stimulates the anterior pituitary to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH); a hormone that has a stimulating effect on the gonads
Endoplasmic Reticulum (ER)
System of membranes forming a network of connecting sacs and canals that wind back and forth through the cytoplasm, from the nucleus almost to the plasma membrane; tubular passageways/canals in the ER carry proteins and other substances through the cytoplasm of the cell from one area to another
cardiovascular disease
System that supplies our body's transportation needs
Cortisol (hydrocortisone)
The chief glucocorticoid; an important role is to help maintain normal blood glucose concentration; cortisol and other glucocorticoids increase gluconeogenesis by promoting the breakdown of tissue proteins to amino acids, especially in muscle cells; amino acids move out of the tissue cells into blood and circulate to the liver; liver cells then change them to glucose by the process of gluconeogenesis; the newly formed glucose leaves the liver cells and enters the blood; this action increases blood glucose concentration; glucocorticoids also help maintain normal blood pressure-they act in a complicated way to make it possible for 2 other hormones secreted by the adrenal medulla to partially constrict blood vessels, a condition necessary for maintaining normal blood pressure; they also act with hormones from the adrenal medulla to produce an anti-inflammatory effect-they bring about a normal recovery from inflammations produced by many kinds of agents, i.e. using hydrocortisone to relieve skin rashes; another effect is their anti-immunity, antiallergy effect - they bring about a decrease in the number of certain cells that produce antibodies; additionally, increased glucocorticoid secretion is one of the first responses to stress
Transcription
The double-stranded molecule separates or unwinds, and a type of of RNA called messenger RNA (mRNA) is formed; each strand of mRNA is a duplicate or a copy of a particular gene sequence along one of the newly separated DNA spirals; RNA is said to have been "transcribed" or copies from its DNA mold or template; the mRNA then functions as a temporary "working copy" of a gene from DNA; the mRNA transcripts pass from the nucleus to the cytoplasm to direct protein synthesis in the ribosomes and ER
Urethra (male)
The ejaculatory duct passes through the substance of the prostate gland and permits sperm to empty into the urethra, which eventually passes through the penis and opens to the exterior at the external urinary meatus
Urinary bladder
The empty urinary bladder lies in the pelvis just behind the pubic symphysis; when full of urine, it projects upward into the lower portion of the abdominal cavity; in women, it sits in front of the uterus, whereas in men, it rests on the prostate; elastic fibers and involuntary muscle fibers in the wall of their urinary bladder make it well suited for expanding to hold variable amounts of urine make it well suited for expanding to hold variable amounts of urine and then contracting to empty itself; mucous membrane containing transitional epithelium lines the urinary bladder; the lining is loosely attached to the deeper muscular layer so that the bladder is very wrinkled and lies in folds called rugae when it is empty; when the bladder is filled , its inner surface may stretch until it is smooth; one triangular area, the trigone, is on the back or posterior surface of the bladder is free of rugae and is always smooth; there, the lining membrane is tightly fixed to the deeper muscle coat; the trigone extends between the openings of the 2 ureters above and the point of exit of the urethra below
lymph
The excess fluid left behind by capillary exchange that drains from tissue spaces and is transported by way of lymphatic vessels to eventually reenter the bloodstream; formed by blood plasma filtering out of the capillaries into the microscopic spaces between tissue cells because of the hydrostatic pressure generated by the pumping section of the heart; there, the liquid is called interstitial fluid (IF) or tissue fluid; much of the interstitial fluid goes back into the blood by the same route it came out; the rest of the IF enters the lymphatic system before it returns to the blood; the fluid, called lymph at this point, enters a network of tiny blind-ended tubes distributed in the tissue spaces; lymph only travels in one direction
External respiration
The exchange of gases between the blood and alveolar air occurs by diffusion; a passive process resulting in movement down a concentration gradient; that is, substances move from an area of high concentration to an area of lower concentration of the diffusing substance; the amounts or concentrations of some blood substances are measured in terms of weight, i.e. the concentration of a particular gas in air or within the blood is expressed pressure exerted by that gas and is reported in millimeters of mercury (mm Hg); several different gases are present in both air and blood; the total pressure of all gases present in an air or blood sample is the sum of the pressures exerted by each of the gases present; because the pressure of the so-called respiratory gases-oxygen (O2) and carbon dioxide (CO2)- in air or blood constitutes only a part of the total pressure present, their concentration is reported as a partial pressure (P); the symbol used to designate partial pressure is the capital letter P preceding the chemical symbol for the gas; respiratory physiologists state that blood gas particles diffuse from from an area of high partial pressure to an area of lower partial pressure; oxygen diffuses "down" its partial pressure gradient; diffusion of carbon dioxide results in its movement from an area of high partial pressure in the pulmonary capillaries to an area of lower partial pressure in alveolar air; once in the alveoli, carbon dioxide leaves the body in expired air
cerebrospinal fluid (CSF)
The fluid that fills the subarachnoid spaces between the pia mater and arachnoid in the brain and spinal cord; also fills spaces in the brain called cerebral ventricles; it forms continually from fluid filtering out of the blood into the choroid plexus and into the ventricles; one of the body's circulating fluids; it seeps from the lateral ventricles into the third ventricle and flows down through the cerebral aqueduct into the fourth ventricle; most of the CSF moves through tiny openings from the fourth ventricle into the subarachnoid space near the cerebellum; some of it moves into the small, tubelike central canal of the spinal cord and then out into the subarachnoid spaces; then CSF moves leisurely down and around the spinal cord and up and around the brain (in the subarachnoid spaces of their meninges) and returns to the blood (in the veins of the brain)
Formation of urine
The kidneys' 2 million or more nephrons balance the composition of the blood plasma, helping maintain a homeostatic constancy for the entire internal environment of the body; in performing this critical function, the kidneys' nephrons must flush out excess/waste molecules by excreting urine; the nephrons form urine by way of a combination of filtration, reabsorption, and secretion
Plasma
The liquid (extracellular) part of blood; consists of water with many substances in it; all of the chemicals needed by cells to stay alive - nutrients, oxygen, and salts, for example-have to be brought to them by the blood; nutrients and salts are dissolved in plasma; a small amount of oxygen is also transported in plasma; wastes that cells must get rid of are dissolved in plasma and transported to the excretory organs; hormones and other regulatory chemicals that help control cells' activities are also dissolved in plasma; volume of the plasma part is usually a little more than half the entire volume of whole blood
Urethra
The lowest part of the urinary tract; to leave the body, urine passes from the bladder, down the urethra, and out of its external opening, the urinary meatus; narrow tube that is only about 4 cm (1.5 in) long in a woman, but it is about 20 cm (8 in) long in a man; in a man, the urethra has 2 functions: 1) it is the terminal portion of the urinary tract, and 2) it is the passageway for movement of the of the reproductive fluid (semen) from the body; in a woman, the urethra is a part of only the urinary tract
Aldosterone
The main mineralocorticoid; helps control the amount of certain mineral salts (mainly sodium chloride) in the blood; its main function is to increase the amount of sodium and decrease the amount of potassium in the blood; increases blood sodium and decreases blood potassium by influencing the kidney tubules; it causes them to speed up their reabsorption of sodium back into the blood so less of it will be lost in urine; at the same time, it causes the tubules to increase their secretion of potassium so that more of this mineral will be lost in the urine; the effects speed up kidney reabsorption of water
Polarization
The membrane of each resting neuron has a slight positive charge on the outside and a negative charge on the inside; this occurs because there is normally an excess of sodium ions (NA+) on the outside of the membrane
Respiratory mucosa
The membrane that lines most of the air distribution tubes in the system; typically ciliated pseudostratified epithelium which means this type of tissue is covered with cilia which can move fluids along the surfaces of a layer of cells; there is also the presence of goblet cells which can produce and release huge amounts of mucus which varies from very watery to very thick depending on the specific location of the mucosa; there are a few areas that are lined with other tissues, i.e. stratified squamous epithelium is found just inside the nostrils, covering the the vocal folds of the larynx and lining the pharynx, and simple squamous epithelium lines the alveoli of the lungs; in addition to serving as air distribution passageways or gas exchange surfaces, the structures of the respiratory tract and lungs cleanse, warm, and humidify inspired air; air entering the nose is generally contaminated with one or more common irritants such as pollen, dust, or insects; a remarkably effective air purification mechanism removes almost every form of contaminant before inspired air reaches the alveoli in the lungs; a layer of protective mucus, a mucous blanket, covers nearly the entire ciliated psuedostratified epithelial lining of the air distribution tubes in the respiratory tree; more than 125 mL of respiratory mucus is produced daily which serves as the most important air purification mechanism; air is purified when contaminants stick to the mucus and become trapped
Plasma proteins
The most abundant type of solute in the plasma that together make up about 7% of the plasma by weight; proteins include albumin, globulins, fibrinogen, and prothrombin
Microscopy
The use of a microscope; Antonie van Leeuwenhoek spent most of his life pursing adventures with the hundreds of microscopes he had built or collected; using simple lenses or combination of lenses, van Leeuwenhoek discovered a whole world of tiny structures he called "animalcules" in body fluids; although almost a century later, scientists would declare that all living organisms are made up of cells, van Leeuwenhoek was the 1st to see and describe human blood cells, human sperm cells, and many other cells and tissues of the body; was also the 1st to observe many microscopic organisms that live on or in the human body, many of which are capable of producing disease; today much more advances microscopes are being used such as electron microscopes that use electron beams rather than light to produce images of very high magnification; cytologists (cell biologists) and histologists (tissue biologists) use microscopes to research the fine structure and function of the human body; a wide variety of professions have found practical applications for microscopy such as pathologists, law enforcement investigators, archaeologists, anthropologists and paleontologists
Stroke Volume (SV)
The volume of blood ejected from the ventricles during each beat which is determined by the volume of blood returned to the heart by the veins or venous return; the higher the venous return, the higher the SV; venous return can change when the volume of the blood changes, as in dehydration or blood loss due to hemorrhage; various hormones can influence total blood volume and also affect SV; the strength of myocardial contraction also helps determine SV; ion imbalances can affect muscle fiber function and impair contraction, thus decreasing SV; valve disorders, coronary artery blockages, or myocardial infarction call decrease stroke volume which may decrease cardiac output
Prostaglandins (PGs)
Tissue hormones; important and powerful lipid substances found in a wide variety of tissues; modified versions of fatty acids; play an important role in communication and in the control of many body functions but do not meet the definition of a typical hormone; in many instances PG is produced in a tissue and then diffuses only a short distance to act on cells within that tissue; typical hormones influence and control activities of widely separated organs; typical PGs influence activities of neighboring cells; best known classes are prostaglandin A (PGA), prostaglandin E (PGE) and prostaglandin F (PGF); have profound effects on many body functions; influence respiration, blood pressure, GI secretions, inflammation, and the reproductive system; researchers believe that most PGs regulate cells by influencing the production of cAMP; already playing an important role in treating high blood pressure, asthma and ulcers; many common treatments like aspirin cause their effects by altering the functions of PGs in the body
white blood cells /(WBCs)/leukocytes
Total number of WBCs per cubic milimeter of whole blood ranges between 5000 and 10,000; When stained on a microscopic slide, the WBC shows a prominent and sometimes oddly shaped nucleus-far different in appearance from the RBC, which has no nucleus; WBCs have no hemoglobin and are almost transparent when unstained; a mass of WBC's look whitish in appearance because of the diffusion of light; different types of WBCs are categorized by the presence or absence of stained granules in their cytoplasm; all of the WBCs are involved in immunity; however, each type and subtype of WBC has its own unique roles to play in immunity, such as phagocytosis of foreign particles or virus-infected cells
Meninges
Tough, fluid-cushioned set of membranes that surrounds the spinal cord and the brain; spinal meninges form a tubelike covering around the spinal cord and line the bony vertebral foramen of the vertebrae that surround the spinal cord; 3 layers of the meninges: dura mater, pia mater and arachnoid mater; also extends up and around the brain to enclose it completely; inner, soft coverings of the CNS; they are surrounded by the hard bone of the skull and vertebrae - forming a highly protective shield from injury
nervous system
Transmits information very rapidly by nerve impulses conducted from one body area to another; organs include brain and spinal cord, numerous nerves of the body, special sense organs such as eyes and ears, and microscopic sense organs such as the ones found in skin; system consists of 2 principal divisions - central nervous system and peripheral nervous system; nervous tissue is the major component; 2 major types of cells are found in nervous tissue: neurons and glia
Central venous pressure
Venous BP within the R atrium; represents the "low end" of the pressure gradient needed to drive blood flow all the way back to the heart; the CVP level is important because it influences the pressure that exists in the large peripheral veins; if the heart beats strongly, the CVP is low as blood enters and leaves the heart chambers efficiently; if the heart is weakened, CVP increases, and the blood flow into the R atrium is slowed; 5 mechanisms help keep venous blood moving back through the cardiovascular circuit and back to the R atrium; they are: 1) continued beating of the heart, which pumps blood through the entire cardiovascular system; 2) adequate BP in the arteries to push blood to and through the veins; 3)semilunar valves in the veins that ensure continued blood flow in one direction (toward the heart); 4)contraction of skeletal muscles, which squeeze veins, producing a kind of pumping action; 5) changing pressures in the chest cavity during breathing that produce a kind of pumping action in the veins in the thorax
Alveoli
Very effective in promoting the rapid and effective exchange of oxygen and carbon dioxide between blood circulating through the lung capillaries and alveolar air; the wall of each alveolus is made up of a single layer of simple squamous epithelial cells and so are the walls of the capillaries that surround and lie in contact with them; between the blood in the capillaries and the air in each alveolus, there is a barrier less than 1 micron thick - this extremely thin barrier is called the respiratory membrane; there are millions of alveoli which means that together they make an enormous surface - approx. 84 square meters (915 square feet); this huge surface area allows large amounts of oxygen and carbon dioxide to be rapidly exchanged
adenohypophysis
anterior pituitary gland; sometimes called the master gland because it exerts tropic control over the structure and function of the thyroid gland, the adrenal cortex, the ovarian follicles, and the corpus luteum; because its secretions are in turn controlled by the hypothalamus and other mechanisms, it is hardly the master of body function it was once thought to be; has the epithelial structure of an endocrine gland; secretes several major hormones ( TSH, ACTH, FSH and LH);
Lymph nodes
small oval clumps of lymphatic tissue located at grouped intervals along lymphatic vessels; some of these nodes may be as small as a pinhead and others as large as a lima bean; filters the lymph as it travels from the tissue spaces to the R lymphatic and thoracic ducts and then into venous blood; their structure makes it possible for them to defend and form WBCs; a typical lymph node's structure is a hollow capsule with nodules of lymphoid tissue suspended by reticular fibers; structure is repeated in all the lymphoid organs; perform biological filtration; once lymph enters the node, it "percolates" slowly through sinuses that surround nodules found in the outer (cortex) and inner (medullary) areas of the node; at the core of each nodule is a germinal center where new cells are produced; in passing through the node, lymph is filtered so that bacteria, cancer cells, virus-infected cells, and damaged tissue cells are removed and prevented from entering the blood and circulating all over the body; debris is trapped by the web of reticular fibers that suspend the lymph nodules; immune cells destroy and break apart the debris by phagocytosis and other biological processes; clusters of lymph nodes in the neck may become infected and swell when there are ear or throat infections; this is why the neck may be palpated during physical exam
Midsagittal plane
Unique type of sagittal plane that divides the body into two equal halves
Nucleus
Viewed under a light microscope, looks like a small sphere in the central portion of the cell; in certain specialized cells, the nucleus may be pushed to one side, perhaps compressed a bit into a more flattened shape; nucleus contains most of the cell's genetic information, which controls every organelle in the cytoplasm, also controls the complex process of cell reproduction; the nucleus must function properly for a cell to accomplish its normal activities and be able to duplicate itself; Core of each atom and is composed of positively charged protons and uncharged neutrons
Diaphragm
Dome-shaped muscular sheet which is the most important muscle for breathing; separates the thoracic cavity above from the abdominopelvic cavity
axial skeleton
Made of bones of the center, or axis, of the body; made up of the bones of the skull, spine, chest, and the hyoid bone in the neck
Inferior
Meaning "towards the feet"; also means "lower" or "below"
Posterior
Means "back" or "in back of"
Proximal
Means "toward or nearest the trunk of the body, or nearest the point of origin of one of its parts"
Lateral
Means "toward the side of the body or away from its midline"
Respiratory physiology
Mechanics of gas exchange at the cellular level and at a gross anatomical level within the lungs
Plane
Must imagine the body being divided by an imaginary flat plate; can also be used to describe movement
Upper abdominopelvic regions of the quadrant
R and L hypochondriac regions and the epigastric region lie above an imaginary line across the abdomen at the level of the 9th rib cartilage
Sagittal plane
Sagittal cut/section that runs along a lengthwise plane from front to back; divides the body or any of its parts into right and left
Subdivide or cut
Smaller segments to facilitate the study of individual organs or the body as a whole; can be done with actual cuts in a dissection or it can be done virtually using either a CT or an MRI
Atom
Smallest unit of matter; composed of several kinds of subatomic particles:protons, electrons and neutrons
Ventral
Term used for humans who walk in an upright position; means toward the belly and can be used instead of "anterior"
Experimentation
Testing out the proposed hypothesis; requires accurate measurement and recording of data, along with logical interpretations of the data
Membrane physiology
The exchange of molecules across the cell membrane
Exercise Physiology
The mechanism and response of the body to movement
Anatomy
The study of the structure of an organism and the relationships of its parts. Derived from 2 word parts that mean "cutting apart"
Cell physiology
Addresses the functioning of individual cells
Negative feedback loops
A feedback loop that causes a system to change in the opposite direction from which it is moving
Tissues
An organization of many cells that act together to perform a common function; may be all kinds of cells but all work together; the arrangement of cells in 1 tissue may form a thin sheet only one cell deep, whereas the cells of another tissue may form huge masses containing millions of cells; the "fabric" of the body; collaborative functioning of tissues within our body's organs maintain homeostatic balance and thus is vital to our survival; differ from each other in the size and shape of their cells., in the amount and kind of material between the cells, and in the special functions they perform to help maintain the body's survival
Effectors
Cause responses that alter conditions in the internal environment
Aging processes
Changes and functions occurring after young adulthood; diminishes efficiency of functions
Renal physiology
Excretion of ions and other metabolites at the kidney
chemical bond
Forms to make atoms more stable
Transverse plane
Horizontal or crosswise plane; divides the body or any of its parts into upper and lower portions
Theory/Law
Hypothesis that has gained a high level of confidence
Energy levels/shells
Way orbitals are arranged depending on their distance from the nucleus; the farther an orbital extends from the nucleus, the higher its energy level is. The energy level closest to the nucleus has one orbital so it can hold two electrons. Next energy level up has up to 4 orbitals so it can hold 8 electrons