MCAT Body Systems

primary germ layers in Gastrulation (phase after fertilization)

Ectoderm- nervous system, pituitary gland, adrenal medulla, cornea/lens, epidermis of skin (hair, nails,sweat, sensory receptors), nasal, oral, anal epithelium = outside the body mesoderm- muscle, bones, connective tissue, cardiovascular, lymphatic system, blood, urogenital organs (kidney, ureters, gonads, reproductive ducts, dermis of skins endoderm- GI tract epithelium (not mouth/anus), GI glands (liver, pancreas), respiratory epithelium, epithelial linings of urogenital organs/ducts, urinary bladder = inside the body

phases of the membrane potential in a cardiac muscle cell

Phase 0: depolarization Fast Na+ channels open (influx) more positive Phase 1: initial repolarization Na+ channels inactivate, K+ channels open (efflux) slight drop in potential (less +) Phase 2: plateau Ca2+ channels open (influx) K+ channels still open (efflux) transient equilibrium Phase 3: repolarization Ca2+ channels close, K+ channels still open (efflux) decrease more - Phase 4: resting potential K+ channels close back to standard membrane potential page 337

percent saturation of hemoglobin

% sat= (# of O2 molecules bound) / (# of O2 binding sites) x 100

the pacemaker potential of the SA node

Phase 4: self depolarization slow inward Na+ current through leak channels Phase 0: depolarization Ca2+ flow making potential more positive Phase 3: repolarization closure of Ca2+ channel and opening of K+ channels bringing the potential back to negative

inspiration is the drawing of air into the lungs by the contraction of the _______ which enlarges the chest/lung ______and expiration is the movement of air __________

diaphragm cavity out of the lungs -inspiration is an active process! -resting expiration is a passive process!

normal sight, nearsightedness, farsightedness, inability to accommodate(focus) terms

emmetropia- normal vision (too much/little curvature results in defects) myopia- nearsightedness corrected by concave lens hyperopia- farsightedness corrected by convex lens presbyopia- inability to accommodate results from loss of flexibility of the lens due to aging

red blood cells

erythrocytes= transport oxygen from lungs to tissues and CO2 from tissues to the lungs (contains millions of molecules of hemoglobin - requires a large surface area for gas exchange achieved by a flat biconcave shape - erythropoietin: stimulates RBC production in bone marrow - has no nucleus or organelles but requires ATP for processes - depends on glycolysis for ATP synthesis

brainstem

contains important processing centers and relays info to or from the cerebellum and cerebrum brainstem= medulla, pons, midbrain altogether

sigmoidal shape on a graph represents __________ binding what curve would represent fetal hemoglobin?

cooperative fetal - shift to the left

coronary arteries coronary veins coronary sinus what does coronary mean?

coronary arteries - first branches from aorta to supply blood to the wall of the heart coronary veins- where deoxygenated blood from the heart collects coronary sinus- located beneath the layer of fat on the outer wall of the heart that merges with the coronary veins (sinus: open space)= deoxygenated blood goes directly into the right atrium coronary= encircle the heart forming a crown shape

corpus callosum cerebrum frontal, parietal, temporal, occipital lobes (4 parts of ) cortex

corpus callosum- think bundle of axons (2 forms of this can have 2 independent minds) cerebrum- largest region of the brain, conscious thought process, intellectual function 4 parts of cerebral cortex frontal lobe- voluntary movement, complex reasoning, problem solving skills parietal lobe- touch, temperature, pressure, vibration, taste (gustation) temporal lobe- auditory, olfactory sensation, short term memory, emotion, language comprehension occipital lobe-visual sensation cortex- means the outside layer

PNS anatomy

- 12 pairs of cranial nerves and 31 pairs of spinal nerves - cranial: sensory/motor info to and from brainstem -spinal: sensory/motor into to and from spinal cord - somatic PNS: innervate skeletal muscle cells, use ACh neurotransmitter, have long dendrite from sensory receptor to the soma -autonomic PNS: sympathetic/parasympathetic = preganglionic(release acetylcholine) & postganglionic (release norephinephrine)

threshold potential

- 50 mV when Na channels are opened to flow into the cell (they can only open at threshold potential) -once its below the threshold the channels close and do no allow the passage of any ions through the channel -sodium channels are upon until +35 mV

vagus nerve

- decreases heart rate and increases GI activity - part of the parasympathetic division of the autonomic nervous system - bundle of axons the end in the ganglia on the surface of the heart, stomach, and visceral organs

platelets and hemostasis

- have no nuclei and limited lifespan derived from megakaryocytes (same as RBC or WBC) -function is to aggregate at the site of damage to a blood vessel wall = platelet plug (helps stop bleeding) hemostasis- mechanism to prevent bleeding - fibrin is a protein that holds platelet plug together to stop bleeding and then it forms into a scab to seal and protect the wound -thrombus : blood clot

respiratory system does what and is lined by what cells?

- regulates pH (when CO2 is exhaled blood becomes more alkaline) Hypervent= more alkaline and hypovent= more acidic - thermoregulation (to prevent heat loss-countercurrent exchange) - protection from disease and particular matter (lungs have a moist surface where chemicals/pathogens can do harm but the mucociliary escalator+macrophages can protect us from harmful particles epithelial cells! (pg 446) has an enormous surface area

hemodynamics

- study of blood flow -driving force blood flow = pressure from arteries to veins - force opposing flow = friction = resistance - Ohms law = Pressure gradient = Q(blood flow)*R(resistance)

endocrine system

- takes longer to communicate signals than nervous system but generally longer lasting effects - regulates metabolism (hours to even days) - signal= hormone that is secreted into the bloodstream by a endocrine gland for distant target cells - endocrine gland: ductless gland who secretory products are picked up by capillaries simply blood to the region - hypothalamus is the portion of the brain that controls the endocrine system "hypothalamus controls the anterior pituitary which controls most of the eccrine system" (fatal if broken= hormone replacement therapy is needed to survive)

endothelial cells are important bc

- they are the inner lining of blood vessels 1. vasodilation/vasoconstriction: secretion of substance to regulate vessel diameter for bp, tissue oxygenation, and thermoregulation 2. inflammation: they increase their expression of adhesion molecules so that white blood cells can adhere and enter the injured tissue 3. angiogenesis: formation of new blood vessels (increases oxygen and nutrients for a developing tumor and can help sustain cell division/growth 4. thrombosis: blood clotting endothelial inhibit coagulation cascade that can create life threatening clots in vessels

pancreas enzymes for sugar levels alpha, beta, sigma

-alpha cells secrete glycogen in response to low blood sugar. glucagon mobilizes stored fuels by stimulating the liver to hydrolyze it and release glucose and adipocytes into the bloodstream -Beta cells secrete insulin in response to elevated blood sugar and it stimulates the removal of glucose from the blood for storage as glycogen or fat -sigma cells secrete somatostatin that inhibits digestive processes

what does the bone marrow do? spleen? tonsils/appendix?

-bone marrow makes blood cells -spleen filters the blood -tonsils/appendix catch pathogens which enter the body and are large lymphatic tissue that can be removed and does not harm the body (unless infected then they need to be removed)

neurons

-cells that transmit/process info from one part of the body to another - info takes the form of action potentials= electrochemical impulses in the membrane traveling like waves along an axon - carry action potentials in one direction

liver functions

-metabolism of fats, proteins, and carbohydrates -Excretion of bilirubin, cholesterol, hormones, and drugs. -Enzyme activation -Storage of glycogen, vitamins, and minerals -Synthesis of plasma proteins, such as albumin, and clotting factors -Blood detoxification and purification from drugs/toxins -Bile production and secretion.

skin

-prevents excessive evaporation of water, protects us from pathogens, and regulates body temp - epidermis(squamous cells) -->dermis -->subcutaneous tissue or hypodermis (layer of fat) - deepest part of the epidermis = stratum basale -skin contains keratin to make the skin waterproof - skin has melanin which is a brown pigment produced by melanocytes to absorb uv light and prevent damage of underlying tissues dermis- has sensory receptors which conveys info about touch pressure pain and temp to central nervous system - sudoriferous (sweat) glands, sebaceous (oil) glands, and hair follicles are found in the dermis - wax glands are called ceruminous glands -sweat contains water, electrolytes, and urea (responsive to aldosterone)

steps of contractile cycle (413)

1. Binding of myosin head to a myosin binding site on actin (cross-bridge formation). Myosin has ADP and Pi bound. 2. Power stroke: myosin head moves into a low energy conformation and pulls the actin chain toward the center of the sarcomere (ADP is released). 3. Binding of new ATP molecule is necessary for release of the actin by the myosin head. 4. ATP hydrolysis occurs immediately and the myosin head is cocked (high energy conformation)

Homeostatic roles of the kidney (urine formation)

1. Filtration: passage of pressurized blood over a filter into the renal tubule (small molecules) 2. Selective reabsorption: takes out useful items back into the bloodstream (glucose, water, aa) leaves wastes and some water in the tubule (active transport) 3. Secretion: addition of substances to the filtrate (back up method when things weren't removed from filtration) 4. Concentration and dilution: selective reabsorption of water to decide whether to make concentrated or dilute urine then whatever remains in the renal tubule gets excreted as urine (volume and osmolarity are checked)

transmission of a signal across a chemical synapse in the nervous system

1. action potential reaches end of axon, synaptic knob 2. depolarization of membrane opens calcium channels 3. exocytosis of neurotransmitters in vesicles occurs 4. neurotransmitters diffuse across synaptic cleft (space between cells) 5. neurotransmitter binds to receptor proteins (ligand gated ion channels) 6. opening of ion channels alters membrane polarization 7. action potential is initiated if depolarization reaches threshold 8. neurotransmitter in cleft is degraded/removed to terminate signal

antibody binding to antigen

1. binding of antibody may directly inactive the antigen 2. binding of antibody can induce phagocytosis of a particle by macrophages or neutrophils 3. presence of antibodies on the surface of the cell can activate the complement system to form holes in the cell membrane and lyse the cell

carbon dioxide is transported in the blood in what ways

1. by conversion of CO2 to carbonic acid that dissociates into bicarbonate and a proton by carbonic anhydrase (principal plasma pH buffer) 2. being stuck to hemoglobin (binds to other sites of the oxygen binding unit-this stabilize tense hb) 3. can be dissolved in blood and carried from the tissues to the lungs (oxygen cannot do this bc its less water soluble than CO2)

how to cope with cold weather

1. contraction of skeletal muscles produces heat (shivering involuntary or jumping voluntary) 2. skin insulates us so that we conserve heat generated by metabolism subcutaneous contains a layer of insulating fat 3. heat loss by conduction is minimized by constriction of blood vessels in the dermis 4. contrivances such as clothing and blankets help us conserve heat

circulatory system goals

1. distribute nutrients from the digestive tract, liver, and fat (adipose) tissue 2. transport O2 from the lungs to the entire body and CO2 from tissues to lungs 3. transport metabolic waste products from tissues to the excretory system (kidneys) 4. transport horses from endocrine glands to targets and provide feedback 5. maintain homeostasis of body temperature 6. hemostasis (blood clotting)

1. the brain is separated into what 3 regions 2. what is the fluid in the CNS called that protects the spinal cord, absorbs shock and exchanges nutrients and waste with the CNS?

1. hindbrain, midbrain, forebrain 2. cerebrospinal fluid (look at go 274 for more info in psychology)

water has a tendency to flow out of the capillaries because (+cycle)

1. hydrostatic pressure (fluid pressure) created by the heart tends to squeeze out water out of the capillaries 2. high osmolarity of the tissue tends to draw water out of the bloodstream cycle: 1. at the beginning the hydrostatic pressure is high water squeeze out into the tissues 2.relative concentration of plasma protein increases due to water leaving 3. at the end the hydrostatic pressure is low, blood concentration is very high, the oncotic pressure (osmotic pressure by plasma proteins) is very high so water flows back into the capillary from the tissue - some water is lost into the tissues (but not a lot) - fluid, proteins, and abc in the tissues are returned to the bloodstream via lymphatic system

the heart rate and blood pressure are tightly regulated by 3 components

1. input: afferent information 2. integration: function of the central nervous system 3. output: efferent information -both are proportional to cardiac output and peripheral resistance

the nervous systems can increase the force of contraction in 2 ways:

1. motor unit recruitment- a group of myofibers innervated by the branches of a single motor neurons axon and a muscle twitch results from the activation of one motor neuron and larger twitch can be obtained by activation (recruiting) more motor neurons 2. Frequency summation- each contraction ends with the SR returns to [Ca] to low resting levels but if the second contraction occurs to quick there is not enough time to return to low [Ca] thus increasing the force and a second contraction builds on the first = results in a very strong contraction known as a tetanus

Spermatogenesis takes place in the ______ and results in _______ from a single spermatogonium. this begins at ______ and continues on a daily basis for the _________. FSH stimulates ________ and LH stimulates ___________

1. seminiferous tubules 2. four haploid sperm 3. puberty 4. life of the male 5. Spermatogenesis 6. testosterone production

what roles do the testes have and where are they kept

1. spermatogenesis (synthesis of sperm) located in the seminiferous tubules 2. secretion of male sex hormones (androgens/testosterone) -they are held together by the scrotum

skeletal system has what 5 roles

1. support the body 2. provide the framework of movement 3. protect vital organs 4. store calcium 5. make the formed elements of the blood in hematopoiesis (abc,wbc,platelets)

skin dissipation of excess heat

1. sweating 2. dilation of blood vessels in the dermis which results in heat loss by conduction or convection when air blows past the skin

anatomy of urinary system

2 kidneys- filter unwanted material from blood and pass it to the bladder for storage --> elimination renal artery- blood enters the kidney thru this artery and blood travels back to the circulatory system from the kidney via renal vein 2 ureters- urine leaves through this into the urninary bladder (muscular organ that stretches when it fills with urine, once full sends a signal to the brain to go pee) 1 urethra- hole where pee comes out

Weber's Law and Signal Detection Theory

2 stimuli must differ by a constant proportion in order for their difference to be perceptible predicts how and when someone will detect the presence of a given sensory stimulus (signal) amidst all of the other sensory stimuli in the background (noise)

Frank-Starling Mechanism

A mechanism by which the stroke volume of the heart is increased by increasing the venous return of the heart (thus stretching the heart muscle, contraction is more forceful, and filled with more blood venous return: return of blood to the heart by the vena cava - to increase the venous return u can increase the total volume of blood by retaining more water/peeing less or by contracting large veins to propel blood toward the heart

blood types

ABO antigen: made up of glycoproteins that are coded for 3 different allele Ia, Ib, i Rh factor antigen: - positive: RR and Rr leads to the expression of proteins on the surface of RBC - negative: rr leads to the absence of the protein AB+ : universal recipient O- : universal donor

creatine phosphate

An energy storage molecule used by muscle tissue. The phosphate from creatine phosphate can be removed and attached to an ADP to generate ATP quickly

female sexual act

Arousal- clitoris and labia minora contain erectile tissue and become engorged with blood via parasympathetic system Orgasm- controlled by the sympathetic nervous system where cervix widens and involves muscle contraction to aid movement of sperm to uterus Resolution- controlled by the sympathetic nervous system but takes 20-30 minutes (no ejaculation)

male sexual act

Arousal- parasympathetic nervous input and is divided in erection and lubrication orgasm- stimulation by the sympathetic nervous system is required for orgasm and is divided in emission(propulsion of sperm from ductus deferens and semen from accessory glands to urethra) and ejaculation (semen propels from urethra to outside of the body by contractions of muscles surrounding the base of the penis - reflex reaction) resolution- return to normal unstimulated state controlled by sympathetic nervous system where there is a constriction of the erectile arteries and decreased blood flow to form a flaccid penis (2-3 mins) - these events are controlled by the spinal cord responding to physical stimulation and input from the brain (cerebral cortex)

bottom-up processing and top-down processing

Bottom Up Processing- sensory receptors works up the complex integration of info occurring in the cell Top Down Processing- brain applies experience and expectations to interpret sensory info -Brain uses a combo of both!!

Divisions of the Nervous System

Central --> Brian and spinal cord Peripheral --> all nerves and sensory structures outside of the brain and spinal cord --> somatic: voluntary control of skeletal muscle OR autonomic: involuntary control of glands and smooth muscle(EX. digestion, perspiration) --> sympathetic: fight or flight OR parasympathetic: rest and digest LOOK AT TABLE PAGE 289

Stages of pregnancy

First trimester- first 8 weeks are majority of the trimester where all major organ systems are present and the embryo is now called a fetus; also the formation of 3 primary germ cells- gastrulation and nervous system- neurulation (1st trimester is where the embryo is most sensitive to toxins/drugs and radiation bc its developing its organs) second trimester- organs/organ systems continue to developed structurally and functionally reaching a weight of about 0.6kg third trimester- rapid fetal growth, deposition of adipose tissue, organ systems are almost fully functional (fetus born 1-2 months early has a good chance of survival) the mom experiences an increase in respiratory rate, blood volume, demand for nutrients/vitamins, uterus and mammary glands gets larger (lactation occurs) in order

examples of neurotransmitters and what can it do

GABA (gamma aminobutyric acid), serotonin, dopamine, norepinephrine Excitatory- when neurotransmitter receptor opens a channel that depolarizes (more positive) Inhibitory- when neurotransmitter receptor induces hyper polarization (more negative)

Classes of antibodies

IgG- 2nd immune response main blood antibody IgM- primary immune response pentameric IgA- found in secretions like saliva/breast milk dimeric IgD- B cell antigen receptor IgE- allergic reactions

Types of Immunity Innate Humoral Cell-mediated

Innate- general non specific protection of the body against invaders (skin) - tears, saliva, and blood contains lysozyme an enzyme that kills bacteria by destroying their cell walls - extreme acidity in the stomach destroys pathogens that are ingested with food or swallowed after being passed out of the respiratory tract - macrophages/neutrophils phagocytize microorganisms -complement system contains 20 proteins that can nonspecifically bind to the surface of foreign cells leading to their destruction Humoral- specific protection by proteins called antibodies or immunoglobulins that specifically recognize and bind to foreign things destroy them and remove them from the body (table on 353) - antibodies are made from B tells - antigen binds to the antibody on the immature B cell to stimulate 2 kinds of cells --> plasma (produce/secret antibody proteins) and memory cells (to remember what to do when the antigen comes back into the body) cell mediated- 2 types of thymus cells (T cells) : t-helpers and t-killers - t helpers activates B cells, t killer cells, and other cells for the immune system by antigens displaying on MHC II = central controller for the IM - t killer detroys abnormal host cells (virus/cancer) that are displaying abnormal antigen on MHC 1

Peristalsis

Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system

Kidneys

Kidneys- filters out waste (small hydrophilic dissolved in plasma such as water, urea, bicarbonate when they are in high concentrations) - More like a sensitive regulator that must keep concentrations at optimum levels (constant concentration of ions, pH, fluid volume (important for bp and cardiac output) - Homeostatic role! = constancy of physiological variables - fundamental unit: nephron composed of a capsule (round region surrounding the capillaries where filtration takes place) and renal tubule (coiled tube) receives filtrate from capillaries in the capsule and empties into a collecting duct where it dumps urine into the renal pelvis PAGE 373

liver colon skin

Liver- chemically modifies waste(large hydrophobic that is too much for the kidneys to filter out) and releases them into bile and makes urea for the bloodstream (excess nitrogen from protein breakdown) urea is excreted in urine Colon- large intestine 3/4 feet long: forms/stores feces until defection also reabsorbs water and ions from feces and excretes excess ions into the feces by active transport (processes waste already destined for excretion) like a passive container for waste (DIGESTION DOES NOT OCCUR HERE) Skin- sweat contains water, ions, and urea that is excreted based on temperature and level of sympathetic nervous system (a secondary form of excretory role bc its not controlled by amount of waste needed for excretion)

approximate atmospheric gas compositions

N2 : 80% O2: 20% H2O: 0.5% CO2: 0.04%

each heartbeat begins as an action potential in the ________ then spreads throughout the ________ causing them to contract and fill the ventricles with blood

SA node atria

absolute refractory period vs relative refractory period

absolute- neuron will not fire another action potential no matter how strong the depolarization is induced (Na channel inactivated) relative- neuron can be induced to transmit an action potential but the depolarization required is greater than normal because the membrane is hyper polarized

acrosome bindin Luteinizing hormone/ follicle stimulating hormone

acrosome- part of the head of the sperm that has hydrolytic enzymes required for penetration of the ovum's protective layers bindin- protein of sperm`s surface that attaches receptors on the zone pellucida surrounding the ovum LH/FSH- stimulates to secret testosterone (inhibin inhibits FSH release)

the ability to _______ to a stimulus is an important property of sensory receptors

adapt (smelling baking bread for the first few minutes, hearing background noise that u only hear for a little bit and then u get used to it)

kidney hormones

aldosterone from adrenal cortex- causes Na reabsorption and K secretion --> [Na] is high and increased blood volume and bp ADH from posterior pituitary- secreted when plasma volume/bp/plasma osmolarity is too low and causes water reabsorption --> more concentrated urine and more diluted blood increased plasma volume calcitonin from C cells in thyroid gland- secrete calcitonin when [Ca] is too high so it removes Ca from the body by deposition in bone, reduced absorption by gut, or excretion in urine parathyroid hormone from parathyroid- function is the opposite of calcintonin EPO from kidney- erythropoietin caused increase synthesis of RBC in bone marrow and released when blood oxygen content falls

amnion yolk sac allantois chorion

amnion- surrounds fluid filled cavity that holds developing embryo (fluid breaks = water breaks before birth) yolk sac- first site of abc synthesis in the embryo allantois- develops the embryonic gut and forms blood vessels of the umbilical cord which transports blood between embryo and placenta chorion- zygotes contribution of placenta - chorion, amnion, yolk sac all come from the blastula (same genome) endometrium comes from the mother so diff genome

oogonia

an immature female reproductive cell that gives rise to primary oocytes by mitosis - occurs prenatally (males produce every day while females are born with it) 7 million in utero but we are born with only 2 million oocytes and after puberty only 400,000 (many are lost= degenerate) -only about 400 oocytes are actually ovulated

pituitary gland (hypophysis) parts

anterior: adenohypophysis; normal endocrine gland controlled by hypothalamic releasing and inhibiting factors posterior: neurohypophysis ; made up of axons which descend from the hypothalamus

axial vs appendicular skeleton

axial = skull to spine to rib cage appendicular = everything else (legs/arms)

Basal Nuclei and Limbic System

basal/cerebral nuclei- known as the basal ganglia, voluntary motor control, habits, works with the cerebellum to coordinate movement initiated by primary motor cortex (inhibitory and cerebellum=excitatory) limbic system- works with the cerebrum, diencephalon, and midbrain, important for emotion and memory LOOK AT TABLE ON PAGE 293

bile

bitter greenish-brown alkaline fluid that aids digestion and is secreted by the liver - made up of acids, cholesterol, bilirubin - once made it can either go into the duodenum or stored in the gallbladder - gallstone is a large crystal formed from bile made with ingredients in incorrect proportions

erection occurs when

blood accumulates at high pressure in the erectile tissue - erectile tissue is in corpora, cavernosa, corpus spongiosum

portal system

blood flows through two consecutive capillary networks before returning to the heart -is an exception to having 2 separate circulations where blood usually passes through only one set of capillaries before returning to the heart

bone marrow vs red marrow vs yellow marrow

bone- non bony material found in shafts of long bone and in pores of spongy bone red- in spongy bone with flat bones site of hematopoiesis increases kidney hormone erythropoietin yellow- shafts of long bones and filled with fat and is inactive

PTH, calcitriol, and calcitonin all have effects on the ___________ PTH and calcitriol have effects on ______

bones and kidneys intestines page 430

dorsal root ganglion and adrenal medulla/cortex

bunch of somatic/autonomic sensory neuron cell bodies located dorsal of the spinal cord adrenal medulla - inner portion of adrenal, part of the sympathetic NS, released epinephrine (adrenaline) adrenal cortex- outer portion of adrenal, endocrine gland, secreting cortisol & aldosterone/sex hormones

soma

central cell body of a neuron where the nucleus and most biosynthetic activity takes place

voltage gated potassium channels are normally _______by the repolarization

closed

the nervous and endocrine system provide _________ integrating and coordinating the activities of the ___________ and __________ of the body

communication tissues organs -nervous system is much faster!

bones are an example of _______ tissue and are derived from ______. They are made of _________fat cells are called _______ cartilage cells are called ______ and bone cells are called______. loose connective tissues are _______ and dense are ______

connective fibroblasts (collagen/elastin) collagen and hydroxyapatite (calcium phosphate crystals) adipocytes, chondrocytes, osteocytes loose= packing, soft between cells, and fat cells dense= fiber, tendon, ligament, cartilage, bone

Loop of henle is a _______ the vasa recta is a _______

countercurrent multiplier that mades the medulla very salty and that this facilities water reabsorption from the collecting ducts and this is how the kidney is capable of making urine with a much higher osmolarity than plasma forms a loop that helps to maintain the high concentration of salt and it returns any water that is reabsorbed from the filtrate back to the bloodstream (countercurrent exchanger)

Once the sperm has penetrated the ovum a fast block of ________ prevents other spermatozoa from fusing with the egg cell membrane

depolarization and Ca2+ influx (cortical reaction) - prevents polyspermy

diastole systole

diastole: relaxation (longer- space between Lub-dub) systole: contraction (shorter) - after systole is done pressure falls and blood flows back from pulmonary artery to right ventricle then to the left - this is called the cardiac cycle (goes back to diastole)

What does the forebrain consist of?

diencephalon- thalamus(process sensory info) and hypothalamus (emotions/autonomic functions/hormonal productions & release and is the main link between nervous and endocrine system) telencephalon- consists of 2 separate cerebral hemispheres -all parts of the CNS and diencephalon forms a single symmetrical stalk

Excretion

disposal of waste - Generally refers to the kidneys but the liver, large intestine, and skin are involved too

analogous structures of male/female reproductive systems

ductus deferens= uterine tubes testis= ovary= gamete/hormone reproduction penis = clitoris= erectile tissue and sensation bulbourethral glands= vestibular glands= lubrication scortum= labia majora = external skin folds androgens = estrogens testosterone = estradiol granulose cell= sustenacular cells = support/nurture developing cells -sex steroid production is controlled by the hypothalamus and anterior pituitary

water to the tissues is called

edema or swelling

exocrine and endocrine secretions

exo- secrete products (digestive enzymes etc) into ducts that drain in the GI lumen endo-ductless glands and their secretions (hormones) are picked up by capillaries and enter bloodstream

structure of the ear

external auditory canal/outer ear- auricle/pinna middle ear- tympanic membrane or eardrum inner ear- cochlea, semicircular canals, urticle, saccule (for balance) Eustachian tube- passageway from back of the throat to the middle ear (to equalize pressure) PICTURE ON PG 301

autoimmunity occurs when the immune system targets normal body cells or tissues and destroys them. it is the result of a __________

failure to eliminate self reactive B/T cells during their development or maturation

the endocrine system performs ________ that is very complex set of variables but can be controlled automatically. Hormones regulate other hormones are called

feedback regulation (mainly negative/inhibition) tropic hormones

Duodenum

first part of the small intestine - has 2 ducts (pancreatic duct that delivers secretions of the panceas) and common bile duct (which delivers biles that is stored in the gall bladder) - bile is a vehicle for the disposal of waste products by the liver and is essential for the digestion of fats

pulmonary edema

fluid in the lungs resulting from increase bp - lymphatic systems prevents this from developing by carrying interstitial fluid out of the lungs

surface tension and what reduces it

force that causes wet hydrophilic surfaces to stick together in the presence of air (tendency of water molecules to clump together) surfactant (soapy surface active substance made up of proteins, phospholipids, and ions) reduces surface tension!

synaptic knob

forms connections with target cells ready for termination so that action potentials can release chemical messengers and travel to the target cell

pitch is the _____ of sound and loudness is the _____ of _________ and we have 2 ears for

frequency amplitude of vibration stereophonic/3D hearing

gustation vs olfaction

gustation- taste, taste receptors(taste buds) can only distinguish sweet, salty, bitter, sour, umami; olfaction- smell, olfactory receptors are in the roof of the nasal cavity (nasopharynx) nerves detect directly to bulbs in the temporal lobe near limbic system (why certain smells reminds u of memories) perception of smell is based on culture and upbringing

noxiuos

harmful

cardiac output equation and what is heart rate

heart rate/pulse: number of times of contraction per minute (Normal is 45 athletes -80 children/elderly) - athletes have a strong heart so they pump more blood each time it contracts resulting in few beats per minute stroke volume: amount fo blood pumped with each systole cardiac output: amount of blood pumped per minute (equal on both right and left ventricle) cardiac output CO = stroke volume SV x heart rate HR

appetite is controlled by lipemia

hormones in the hypothalamus lipemia- fat in the blood making blood a milky yellow color

hemoglobin has a higher affinity for oxygen in the tissues/lungs because

lungs because the partial pressure of oxygen is higher in the lungs than tissue = higher partial pressure will have tales tone of the subunits occupied with oxygen - in tissues hb has a low affinity for oxygen and tends to release any oxygen it carries

two types of hormones

hydrophilic- large/small peptide bind to receptors on cell surface - made in the RER (made and wait in vesicles until they are needed) and modified in Golgi - must perform 2nd messenger cascade (modify activity of existing enzymes in the cytoplasm) - free in blood, rapid, short lived hydrophobic- small steroid bind to receptors in the cellular interior - made from cholesterol in SER (only made if needed are not in vesicles that wait, made and used right away) -binds to a receptor in the cytoplasm can go freely through membrane -stuck to protein carrier in the bloodstream -alters gene expression by regulating DNA transcription -slow long lasting

main connection between nervous and endocrine system

hypothalamic pituitary axis

Process of inspiration and expiration

inspiration - 1. diaphragm contracts and flattens (moves down) 2. volume of the chest cavity expands 3. pleural pressure decreases (more negative ) 4. lungs expand outwards 5. pressure in alveoli becomes negative 6. air enters lungs and alveoli expiration- opposite of inspiration!

action potentials requires the movement of _______

ions across the membrane to create a wave of depolarization

left vs right hemisphere of the brain

left- controls motor functions of the right side of the body and responsible for speech right- controls motor functions of the left side of the body and responsible for visual spatial reasoning and music BRAIN PICS ON PG 290/292

white blood cells

leukocytes, fight infection and dispose of debris - have eukaryotic structure (organelles) - some move by amoeboid crawling important bc they can squeeze out of capillary intercellular junctions and roam free in tissues hunting for foreign parties of pathogens - others move by chemotaxis: directed by chemical stimuli (toxins, waste)

endomertrium

lining of the uterus responsible for nourishing a developing embryo and if not pregnant it sheds each month producing menstrual bleeding uterine tubes= Fallopian tubes have fimbriae that brush against the ovary (fingerlike structures)

_______ removes many wastes and converts them into forms which can be excreted in feces. some compounds are passed into the gut as _______ and other wastes are excreted by the ________

liver bile kidneys

receiving info is the sensory function of the nervous system (NS) Received by ________ processed by _________ and motor function is performed by ___________

peripheral NS central NS peripheral NS

macrophage B cell T cell neutrophil eosinophil basophil SIX TYPES OF LEUKOCYTES

macrophage- phagocytose debris B cell: mature into plasma cell produce antibodies T cell: kill virus infected cells, tumor cells, reject tissue grafts, control immune response neutrophil: phagocytose bacteria (results in pus) eosinophil: destroy parasites; allergic reactions basophil: store/release histamine; allergic rxns

functional syncytium

mass of merging cells that function as a unit found in cardiac muscle cells and communicate vis gap junctions = electrical synapse - voltage gated ion channels are required for action potentials (sodium and calcium)

spirometry

measurement of the volume of air entering or exiting the lungs at various stages of ventilation and a spirometer is used for this measurement TV: tidal volume (amount of air that moves in/out of lungs with normal light breathing ERV: expiratory reserve volume (volume of air that can be inspired after a relaxed inspiration FRC: functional residual capacity (volume of air left in the lungs are resting expiration IC: inspiratory capacity (max volume of air which can be inhaled after a resting expiration RV: residual volume ( amount of air that remains in the lungs after the strongest possible expiration) VC: vital capacity (max amount of air that can be forced out of the lungs after first taking the deepest breathes possible TLC: total lung capacity ( vital capacity plus residual volume TLV = VC + RV)

types of sensory receptors (detects one stimulus from another)

mechanoreceptors- mechanical disturbances such as pressure sensors in the skin, detects vibrations by sound waves chemoreceptors- chemicals, smells things, respond to changes in pH, PCO2, PO2 levels in the wall or arteries electromagnetic receptors- EM waves, retina of the eye thermoreceptors- changes in temp, autonomic/somatic Nociceptors- pain receptors by tissue injury, simplest chemoreceptor, can be autonomic/ somatic

What does the hindbrain consist of? the midbrain?

medulla- connects brain to spinal cord and functions as relaying info to other parts of the brain, autonomic functions (bp), & respiratory rhythms pons- connects brain stem with cerebellum and controls movement/balance/antigravity posture cerebellum- processes sensory input and motor functions midbrain- visual and auditory information + arousal and wakefulness

heat is generated by _______ in humans. we are ______

metabolic processes and muscle contraction homeotherms (constant body temp)

Thyroid homers and cortisol habe broad effects on ________ and ______ usage

metabolism and energy usage

encoding sensory stimuli modality, location, intensity, duration

modality- based on which type of receptor is firing location- communicated by the receptive field of the sensory receptor sending the signal intensity- frequency of action potentials detected by sensory receptors duration- how long action potentials are fired (some can be as long as the stimulus continues or others can be only when the stimulus begins

male and female embryos are indistinguishable but early embryos that lack a Y chromosome will posses ________ and develop ________. With the Y chromosome, the embryo has ______ and develops _______

mullerian ducts that develop female internal genitalia (uterine tubes, uterus, vagina) wolffian ducts that develop male integral genitalia (epididymus, seminal vesicles, ductus deferens) testosterone produces to create the testes -external (labia/clit) are not derived from mullerian ducts form by default

2 types of effectors where motor neurons carry info from the NS toward organs and what carries info toward the central NS

muscles and glands -efferents (neurons that go away from the central NS) go to effectors sensory neurons = afferent neurons

proprio

pertaining to the self - proprioception/kinesthetic sense: awareness of self (ex. body part position) = important example= muscle spindle specialized to detect muscle stretch

axons are wrapped in an insulating sheath called _____ and made by _______ cells _____ but have ______ do that ions can flow from node to node

myelin schwann cells nodes of Ranvier = process is called saltatory conduction - no ions can enter or leave a cell that has a myelin sheath= no action potentials - amount of energy consumed by the Na/K atpase is much less in myelinated (white matter) axons than in unmyelinated (grey matter)

equilibrium potential

no net movement of ions occurs - Na is a positive equilibrium potential ion (out of cell) - K is a negative equilibrium potential ion (into cell) - can be predicted by Nernst Eq: E ion= RT/zF ln ([X]out/[X]in) z: valence of ion aka charge R/F: constants

glial cells

non neuronal cells that provide structural and metabolic support of neurons - maintains a resting membrane potential but does not generate action potentials

inhaled air goes in what pathway

nose --> nasal cavity --> pharynx --> larynx --> trachea --> bronchi --> terminal bronchioles --> respiratory bronchioles --> alveolar ducts --> alveoli

the excitation of the heart is influenced by __________. the sinoatrial node does what?

nothing! (hormone, neurons, etc does not stimulate the heart but can change the rate) Sinoatrial node- initiation of action potential that starts each cardiac cycle within the heart itself located in the right atrium and act as at the pacemaker of the heart

capillaries transport ________________ cells through clefts

nutrients waste and white blood cells -O2 and CO2 pass through simple diffusion

lymphatic system

one way flow system which being with tiny lymphatic capillaries in all the tissues of the body that merge to form larger lymphatic vessels - acts like a suction pump to receive water, proteins, and abc from tissues - lymph noses have millions of abc that initiate an immune response again anything foreign that have been picked up by the lymph (fluid in vessels)

ovarian cycle vs uterine cycle

ovarian- has 3 phases 1. follicular phase: follicle matures and secretes estrogen lasts for about 13 days 2. ovulatory phase: 2nd oocyte is released from ovary and follicle becomes corpus luteum lasts for 14 days 3. luteal phase: full formation fo corpus luteum in ovary secretes estrogen/progesterone; lasts 14 days - hormones from this cycle direct the uterine cycle uterine- focus on the preparation of endometrium for potential implantation of fertilized egg 3 phases 1. menstruation: triggered by degeneration of corpus luteum and drop in estrogen/progesterone levels; this produces bleeding for about 5 days 2. proliferative: estrogen produced by follicle for a new endometrium 9 days 3. secretory: develops endometrium by corpus luteum producing estrogen/progesterone and if pregnancy doesn't occur= death of corpus luteum and decline in secretion of e/p triggers menstruation 14 days levels of e/p are done in anterior pituitary and hypothalamus

the liver receives ______ from the hepatic arteries and _______ draining the stomach and intestines throughout the __________. the lung along with _____ are able to store glycogen and break it down when ______ is needed but only the liver is able to release free glucose to the __________

oxygenated blood venous blood hepatic portal vein skeletal muscles glucose bloodstream (bc it has the enzyme required for breakdown)

stomach characteristics

pH: 2 bc of HCl of parietal cells having a low pH helps destroy microorganisms, acid catalyzed hydrolysis of proteins, and conversion of pepsinogen to pepsin (breakdown of proteins)

the brain employs _______ processing

parallel processing so that many aspects of visual stimulus (motion, color,form) can be processed simultaneously instead of a step by step fashion

parturition 1st stage of labor 2nd stage of labor 3rd stage of labor

parturition - act of giving birth depends on the muscle contractions of the uterine wall (very high level of progesterone) 1st stage of labor- dilation of the cervix 2nd stage of labor- birth; baby moves through the cervix and birth canal 3rd stage of labor- expulsion of the placenta -prolactin produces milk and oxytocin stimulates milk ejection (this stops occurring once mother stops nursing) labor is a positive feedback cycles triggered by uterine contractions that push the baby head on the cervix (oxytocin release and causes strong contractions to released the baby)

perfusion ischemia hypoxia arteries veins capillaries arterioles venules

perfusion- flow of blood through a tissue ischemia- inadequate blood flow (results in tissue damage bc of O2 shortages, nutrients, and buildup of waste) hypoxia- god circulation but the supply of O2 is reduced so waste is not properly reduced arteries- vessels that carry blood away from the heart (high pressure) some are oxy/deoxygenated veins- vessels that carry blood toward the heart (low pressure) arterioles- small arteries that are far away from the heart where the pressure is low and they have smooth muscles in their walls so that they can restrict/increase flow of blood into the capillaries capillaries- very small vessels that allow exchange between blood and tissue (allows one blood cell to pass) - all exchange from blood/tissue occurs in the capillaries venules- small veins passing through the capillaries and then tiny veins leading back to the heart

parts of the blood

plasma= liquid portion of blood that contains water, electrolytes, glucose, hormones, waste(urea), proteins, lipoproteins(transfer lipids in bloodstream), buffers, CO2, O2, fibrinogen(blood clotting) 54% formed elements= cellular elements of blood hematocrit= red blood cells 45% (less in females) leukocytes= white blood cells and platelets 1% principle blood buffer= bicarbonate HCO3- which prevents pH changes (ex.lactic acid buildup)

hCG (human chorionic gonadotropin) is a hormone tested for in _______ because its presence confirms the presence of an _______

pregnancy; embryo - this happens bc of elevated e/p

fate of follicle (oocyte + granulosa cells)

primordial follicle --> maturing follicules --> Graafian follicule --> remnants of graafian follicle and ovulated oocyte --> corpus luteum --> degenerating corpus luteum

differentiaion

process in which cells become specialized in a specific structure and function totipotent- can give rise to any of the 220 cell types found in an embryo as well as extra-embryonic cells (least specialized) pluripotent- can give rise to all cell types of the body but are more specialized than toti (but not the placenta) multipotent- can develop into a limited number of cell types in a particular lineage (but not all) most specialized! - stem cells can become any cell in the body - cells are determined before they are differentiated and is induced by the cell's environment -dedifferentiation happens when cells unspecialize and become totipotent (if its uncontrolled then it can become cancer) ALL CELLS HAVE THE SAME GENOME ITS JUST THE FUNCTION OF THEM ARE DIFFERENT

resting membrane potential (RMP) and depolarization

resting membrane potential - electric potential across the membrane in a passive way= -70mV (negative volts= cell is slightly always negative than environment) - ALL CELLS HAVE RMP Depolarization- depolarized: action potential (+ inside cell) - hyperpolarized: at rest (- inside cell) - repolarized: back to - inside the cell (bv inactivating Na channels K+ open and K+ leak channels/NaK atpase stay open) - THIS IS DUE TO ION CHANNELS FLOWING IN AND OUT OF THE CELL

parts of the heart (blood flow)

right side: pumps blood to the lungs and back to the heart = pulmonary circulation= deoxygenated blood left side: pumps blood to the rest of the body and back to the heart= systemic circulation = oxygenated blood - both sides have one atrium and one ventricle each - sides are separated by a thick muscular wall

parts of the eye

sclera- white of the eye choroid- made up of dark pigment cells that absorb excess light within the eye retina- surface upon which light is focused using electromagnetic receptor cells known as rods/cones for detecting light anterior chamber- inside the cornea aqueous humor- fluid in the anterior chamber iris- colored part of the eye that regulates the diameter of the pupil posterior chamber- behind the iris that has an aqueous humor lens- fine-tune the angle of incoming light ciliary muscle- curvature of the lens (refractive power) opsin- protein bound to retinal derived from vitamin A

the passage way of sperm

seminiferous tubules --> epididymis (mature sperm but immobile) --> ductus deferens (mobile/inactive)--> inguinal canal --> pelvic cavity --> ejaculatory duct --> urethra semen is the supportive fluid for sperm (cell)!!!

autocrine activity

signaling molecules modify the activity of the cell which secreted them

all organisms exchange respiratory gases via _________ across the plasma membrane

simple diffusion - ventilation is the process of simple movements of air into and out of the lungs (only ventilation: conduction zone) -respiration is the process of gas exchange between lungs and blood or blood and other tissues (only respiration: respiratory zone)

skeletal muscle cardiac muscle smooth muscle

skeletal- voluntary, contracts in response to stimulation by somatic motor neurons (striated bc of sarcomeres) - cannot move alone needs bones for movement to occur (one muscle attached at each end of 2 diff bones by tendons) and has multiple nuclei per cell (spiking AP) cardiac- only found in the wall of the heart (striated) have one nucleus per cell, connected by intercalated disks, and Ca contraction comes from SR, contraction does not depend on stimulation from motor neurons (spike and then plateau pg. 420) smooth- found in the walls of GI tract, urinary system, and uterus (responsible for GI motility, constriction of blood vessels, uterine contractions etc) - very small cells with 1 nucleus dispersed in the cytoplasm and not organized by sarcomeres contraction is regulated by MLCK (pg. 422) have a constant fluctuating resting potential - we have no control over cardiac or smooth muscle bc its controlled over the autonomic nervous system -LOOK AT CHART ON PG 423

from sound to hearing

sound waves -> auricle -> external auditory canal -> tympanic membrane -> malleus -> incus -> stapes -> oval window -> perilymph -> endolymph -> basilar membrane -> auditory hair cells -> tectorial membrane -> neurotransmitters stimulate bipolar auditory neurons -> brain -> perception

hepatic portal vein

special vein where amino acids and glucose are absorbed from the digestive tract and carried to the liver and connects 2 capillary beds (intestinal wall and liver)

axons and dendrites

specialized extensions/projections of neurons that send and receive information from neurons - each neuron has only one axon but many dendrites - neurons with 1 dendrite= bipolar and many= multipolar - dendrites receive signals and axons carry action potentials away from the cell body

Gametogenesis

spermatogonium- "gonna" be a sperm (precursor) mitotically reproduce, replicate DNA in S sphase primary spermatocyte- "cyte" undergoes meiotic division, meiosis 1 secondary spermatocyte- "cyte" undergoes second meiotic division, meiosis 2 spermatid- almost mature kid, turns into a spermatozoan spermatozoan- mature sperm, found in seminiferous tubule and epididymis

estrogen is a _____ that helps develop female secondary sexual characteristics in ________ progesterone is a _____ involved in _______ regulation of the menstral cycle and pregnancy but with different _______

steroid hormone; menstral cycle and pregnancy steroid hormone; hormonal; effects

factors that regulate ventilation rate

stretch of lung - stretch receptor of lung - inhibits inspiration increased PCO2 - peripheral chemoreceptors and medulla respiratory- increases PCO2 causes decrease in pH via carbonic anhydrase the decrease in pH is what increases respiratory rate decrease PCO2- peripheral chemoreceptors- increases respiratory rate chemical irritation- irritant receptor in lung- causes coughing and or bronchoconstriction

How does the eye work

structures of the eye forms an imagine on the retina which detects light and converts the stimuli into action potentials to send to the brain 1. light enters the eye passing the cornea (clear portion of the front of the eye) 2. light is bent and refracted as it passes thru the cornea

sustentacular cells testicular interstitium interstitial cells epididymis seminal vesicles accessory glands

sustentacular cells- protect and nurture developing sperm testicular interstitium- tissue between seminiferous tubules interstitial cells-make androgens (testosterone) epididymis-long coil tubes located on the back of each testicle seminal vesicles-pair of glands located on the back of the bladder and secrete 60% of the total volume of semen into the ejaculatory duct (nourishes sperm) accessory glands- seminal vesicles (60%), prostate(35%-nourishes and coagulation), and bulbourethral glands(3%- lubricate urethra neutralize acids in man/woman) produce semen and it travels to the urethra - testes produce 2% (male gamete)

sperm/spermatozoa swim through the femal genetical tract to react the egg/ova and fuse with it, the process called _______ resulting in a _______. the process begins where diploid germ cells undergo _______ to produce haploid gametes

syngamy zygote meiotic division look at pg 469

kidneys have built in mechanisms to help regulate ______ and _____ blood pressures and constant blood _____

systemic and local - a release of aldosterone raises blood pressure by increasing sodium retention pH! - when plasma pH is too high, HCO3- is excreted in the urine and when it is too low H+ is excreted by carbonic anhydrase - lungs also play in this to regulate the pH by exhaling excess CO2 the lung removes H2CO3 from the blood and raises the pH

tendon flexing, extending, abducting, adducting origin vs insertion antagonistic vs synergistic fascicles

tendon- connects muscles to bone and are strong connective tissues (collagen) flexing- reducing angle of the joint extending- increasing angle of the joint abducting- moving away from the body midline adducting- moving toward the body midline origin- point on the bone where the muscle attaches and insertion is the point where the muscle attaches the bone more distant from the center of the body (when a muscle contracts the insertion point is Brough closer to its origin) antagonists- muscles that move in opposite directions and synergistic is in the same direction fascicles- connective tissue that holds the contractile tissue together in bundles

hemoglobin has 4 subunits so that 4 oxygens can bind but when there are none bound it is in a __________ state

tense= low affinity stabilized by decreased pH, increased pCO2, increase temp = Bohr effect - once one of the subunits is bound to an oxygen it changes to relaxed conformation = higher affinity - binding = cooperatively

why do tense stressed out people have high blood pressure

tension and stress are similar to fear and both involve activation of the sympathetic nervous system

summation

the decision by a neuron where to fire an action potential is determined by adding the effect of all synapses impinging on the neuron both excitatory and inhibitory !

enteric nervous system

the nervous system of the digestive tract that regulates local blood flow, gut movements, and exchange of fluid from the gut to and from its lumen

the intrinsic firing rate of the SA node is 120 beats per minute but our normal heart rate is 60-80 because

the parasympathetic nervous system continually inhibits depolarization of the SA node - the parasympathetic system controls the heart to modulate the rate by inhibiting rapid automaticity !!!

blood pressure

the pressure that is exerted by the blood against the walls of arteries - systolic- highest arterial pressure that occurs during contraction - diastolic- lowest arterial pressure that occurs between heartbeats and anytime in the cardiac cycle ! - pressure is highest in the aorta, arteries, arterioles, left ventricle --> pressure decreases with capillaries ->venules, veins, vena cava (in that order)

atrophy

the wasting away of a body organ or tissue; any progressive decline or failure

digestive system

to digest and absorb food and protect from disease this is done by enzymatic hydrolysis - digestion occurs in the GI tract (gut) long muscular tube extending from the mouth to the anus - mouth, pharynx(throat), esophagus, liver, gallbladder, pancreas - composed of epithelial cells GI : - exhibits automaticity where it contracts randomly which any stimulation due to spontaneous depolarization - is a functional syncytium so when one cell has an action potential and contracts the impulse spreads to nearby cells - has its own nervous system for motility (can be increased/decreased by hormonal input) - parasympathetic nervous system stimulates molitity and causes sphincters to relax (passage of food thru the gut)

trachea esophagus small intestine intestinal villus

trachea- cartilage lined tube at the front of the neck for air to and from the lungs esophagus- muscular tube behind the trachea for food/drink from pharynx (throat) to stomach epiglottis- flap that disables food to enter the trachea small intestine- food leaving the stomach enters the small intestine which is a tube that is 10 feet long and is separated into segments called duodenum, jejunum, ileum tiny, fingerlike projection that extends outward from the lining of the small intestine

Fertilization takes place in the ________ and cleavage beings 24-36 hours later. the _______ becomes a morula then blastula and it implants in the endometrium

uterine tubes; zygote

AV valve (Atrioventricular) bicuspid tricuspid semilunar valve why are valves important?

valve which allows blood to flow from the atria to the ventricles bicuspid- av valve between left atrium and left ventricle tricuspid - av value between right atrium and right ventricle semilunar valve- pulmonary and aortic semilunar valves between large arteries and ventricles - going through capillaries results in a decrease in blood pressure so that is why contraction occurs so it pressurizes the blood to make it move forward - Lub-dup sounds are produced by the valves slamming shut (Lub closure of av at the beginning of systole and dub is the closure of semilunar valves at the end of systole)

valve atria ventricle aorta deoxygenated/oxygenated blood flow

valve- one way flow of blood at very high pressure (artial pressure is lower) atria- chamber waiting room where blood can collect from the veins before getting pumped into the ventricles ventricle- chamber pumping blood out of the heart at high pressures into arteries aorta- single large artery -right atrium receives deoxygenated blood from the systemic circulation and pumps into the right ventricle then blood passes through pulmonary arteries to the lungs. oxygenated blood from the lungs return through pulmonary veins to the left atrium and pumped into the left ventricle before being pumped out of the heart in a single large artery (aorta) to the systemic circulation

synaptic transmission and what is a synapse

when an action potential reaches the end of an axon at a synapse, the signal is transformed into a chemical signal with the release of neurotransmitter into the synaptic cleft (space between cells) Synapse- junction between axon terminus of one neuron and the dendrites, soma, or axon of the second neuron or organ - Electrical synapse: when cytoplasms of 2 cells are joined by gap junctions (AP will move from 1 to another cell- common in muscles) - Chemical synapse: ends of axons where they meet their target cell and where action potential is converted into a chemical signal

mouth

where digestion begins 1. fragmentation by chewing, incisors (front teeth) and cuspids (canine teeth) are for tearing and molars are for grinding 2. lubrication by saliva hydrolyzing starch breaking it into fragments and breaking into disaccharides (proteins are not digested here) also contains lysozyme which attacks bacterial cell walls 3. enzymatic digestion