Final Anatomy & Physiology Exam

In extending the arm, the role of the tricpes brachii is to act as the:

Antagonist

Which of the following bones is not apart of the axial skeleton?

Clavicle

This type of neural circuit consists of a single presynaptic neuron synapsing with several postsynaptic neurons

Diverging circuit

Describe hypertrophy and muscular atrophy

Hypertrophy: The muscle growth that occurs after birth occurs by enlargement of existing muscle fibers called muscular hypertrophy. It is due to an increased production of myofibrils, mitochondria, sarcoplasmic reticulum, and other organelles. It results from forceful and repetitive muscular activity such as strength training. Hypertrophied muscles contain more myofibrils, they are able to do perform more forceful contractions. Muscular Atrophy: A decrease in size of individual muscle fibers as a result of progressive loss of myofibrils. Atrophy that occurs because muscles are not used is referred to as disuse atrophy. As a result of this, the flow of nerve impulses to inactive skeletal muscle is greatly reduced -- at this point the condition is reversible. If instead the nerve supply is disrupted or cut, then the muscle undergoes denervation atrophy which is irreversible and replaced by fibrous connective tissue.

Describe the events of signal transmission at electrical and chemical synapses

Electrical Synapses: At an electrical synapse, action potentials (impulses) conduct directly between the plasma membranes of adjacent neurons through structures called gap junctions. Each gap junction contains a hundred or so tubular connexons, which act like tunnels to connect the cytosol of the two cells directly. As ions flow from one cell to the next through the connexons, the action potential spreads from cell to cell. Gap junctions are common in visceral smooth muscle, cardiac muscle, and the developing embryo. They also occur in the brain. 1.Faster communication. Because action potentials conduct directly through gap junctions, electrical synapses are faster than chemical synapses. At an electrical synapse, the action potential passes directly from the presynaptic cell to the postsynaptic cell. The events that occur at a chemical synapse take some time and delay communication slightly. 2.Synchronization. Electrical synapses can synchronize (coordinate) the activity of a group of neurons or muscle fibers. In other words, a large number of neurons or muscle fibers can produce action potentials in unison if they are connected by gap junctions. The value of synchronized action potentials in the heart or in visceral smooth muscle is coordinated contraction of these fibers to produce a heartbeat or move food through the gastrointestinal tract. Chemical Synapses: Although the plasma membranes of presynaptic and postsynaptic neurons in a chemical synapse are close, they do not touch. They are separated by the synaptic cleft, a space of 20-50 nm* that is filled with interstitial fluid. Nerve impulses cannot conduct across the synaptic cleft, so an alternative, indirect form of communication occurs. In response to a nerve impulse, the presynaptic neuron releases a neurotransmitter that diffuses through the fluid in the synaptic cleft and binds to receptors in the plasma membrane of the postsynaptic neuron. The postsynaptic neuron receives the chemical signal and in turn produces a postsynaptic potential, a type of graded potential. Thus, the presynaptic neuron converts an electrical signal (nerve impulse) into a chemical signal (released neurotransmitter). The postsynaptic neuron receives the chemical signal and in turn generates an electrical signal (postsynaptic potential). The time required for these processes at a chemical synapse, a synaptic delay of about 0.5 msec, is the reason that chemical synapses relay signals more slowly than electrical synapses. 1) A nerve impulse arrives at a synaptic end bulb (or at a varicosity) of a presynaptic axon. 2) The depolarizing phase of the nerve impulse opens voltage-gated Ca2+ channels, which are present in the membrane of synaptic end bulbs. Because calcium ions are more concentrated in the extracellular fluid, Ca2+ flows inward through the opened channels. 3)A n increase in the concentration of Ca2+ inside the presynaptic neuron serves as a signal that triggers exocytosis of the synaptic vesicles. As vesicle membranes merge with the plasma membrane, neurotransmitter molecules within the vesicles are released into the synaptic cleft. Each synaptic vesicle contains several thousand molecules of neurotransmitter. 4) The neurotransmitter molecules diffuse across the synaptic cleft and bind to neurotransmitter receptors in the postsynaptic neuron's plasma membrane. The receptor shown in Figure 12.23 is part of a ligand-gated channel (see Figure 12.11b); you will soon learn that this type of neurotransmitter receptor is called an ionotropic receptor. Not all neurotransmitters bind to ionotropic receptors; some bind to metabotropic receptors (described shortly). 5) Binding of neurotransmitter molecules to their receptors on ligand-gated channels opens the channels and allows particular ions to flow across the membrane. 6) As ions flow through the opened channels, the voltage across the membrane changes. This change in membrane voltage is a postsynaptic potential. Depending on which ions the channels admit, the postsynaptic potential may be a depolarization (excitation) or a hyperpolarization (inhibition). For example, opening of Na+ channels allows inflow of Na+, which causes depolarization. However, opening of Cl− or K+ channels causes hyperpolarization. Opening Cl− channels permits Cl− to move into the cell, while opening the K+ channels allows K+ to move out—in either event, the inside of the cell becomes more negative. 7) When a depolarizing postsynaptic potential reaches threshold, it triggers an action potential in the axon of the postsynaptic neuron. * At most chemical synapses, only one way information transfer can occur. Many electrical synapses work in two directions. **** A synapse is the site where two neurons or a neuron and an effector communicate.

Repair in CNS vs PNS

In the CNS there is little to no repair due to inhibitory influences from neuroglia, mainly oligodendrocytes, the absence of growth stimulating cues that were present during fetal development, and rapid formation of scar tissue In the PNS repair is possible if cell body is in tact, Schwann cells are functional, and scar tissue formation does not occur too rapidly

Recall the 11 systems in the body, representative organs present in each, and their general functions.

Integumentary: Components: Skin and associated structures, such as hair, fingernails and toenails, sweat glands, and oil glands. Functions: Protects body; helps regulate body temperature; eliminates some wastes; helps make vitamin D; detects sensations such as touch, pain, warmth, and cold; stores fat and provides insulation. Skeletal: Components: Bones and joints of the body and their associated cartilages. Functions: Supports and protects body; provides surface area for muscle attachments; aids body movements; houses cells that produce blood cells; stores minerals and lipids (fats). Muscular: Components: Specifically, skeletal muscle tissue—muscle usually attached to bones (other muscle tissues include smooth and cardiac). Functions: Participates in body movements, such as walking; maintains posture; produces heat. Nervous: Components: Brain, spinal cord, nerves, and special sense organs, such as eyes and ears. Functions: Generates action potentials (nerve impulses) to regulate body activities; detects changes in body's internal and external environments, interprets changes, and responds by causing muscular contractions or glandular secretions. Endocrine: Components: Hormone-producing glands (pineal gland, hypothalamus, pituitary gland, thymus, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries, and testes) and hormone-producing cells in several other organs. Functions: Regulates body activities by releasing hormones (chemical messengers transported in blood from endocrine gland or tissue to target organ). Cardiovascular: Components: Blood, heart, and blood vessels. Functions: Heart pumps blood through blood vessels; blood carries oxygen and nutrients to cells and carbon dioxide and wastes away from cells and helps regulate acid-base balance, temperature, and water content of body fluids; blood components help defend against disease and repair damaged blood vessels. Lymphatic: Components: Lymphatic fluid and vessels; spleen, thymus, lymph nodes, and tonsils; cells that carry out immune responses (B cells, T cells, and others). Functions: Returns proteins and fluid to blood; carries lipids from gastrointestinal tract to blood; contains sites of maturation and proliferation of B cells and T cells that protect against disease-causing microbes. Respiratory: Components: Lungs and air passageways such as the pharynx (throat), larynx (voice box), trachea (windpipe), and bronchial tubes leading into and out of lungs. Functions: Transfers oxygen from inhaled air to blood and carbon dioxide from blood to exhaled air; helps regulate acid-base balance of body fluids; air flowing out of lungs through vocal cords produces sounds. Digestive: Components: Organs of gastrointestinal tract, a long tube that includes the mouth, pharynx (throat), esophagus (food tube), stomach, small and large intestines, and anus; also includes accessory organs that assist in digestive processes, such as salivary glands, liver, gallbladder, and pancreas. Functions: Achieves physical and chemical breakdown of food; absorbs nutrients; eliminates solid wastes. Urinary: Components: Kidneys, ureters, urinary bladder, and urethra. Functions: Produces, stores, and eliminates urine; eliminates wastes and regulates volume and chemical composition of blood; helps maintain the acid-base balance of body fluids; maintains body's mineral balance; helps regulate production of red blood cells. Reproductive: Components: Gonads (testes in males and ovaries in females) and associated organs (uterine tubes or fallopian tubes, uterus, vagina, and mammary glands in females and epididymis, ductus or (vas) deferens, seminal vesicles, prostate, and penis in males). Functions: Gonads produce gametes (sperm or oocytes) that unite to form a new organism; gonads also release hormones that regulate reproduction and other body processes; associated organs transport and store gametes; mammary glands produce milk

Describe the steps of intramembranous and endochondral ossification.

Intramembraneous ossification: Bone forms directly within mesenchyme, which resembles membranes. It is the simpler of the two methods. The flat bones of the skull, most of the facial bones, and medial part of clavicle are formed this way. Steps 1) Development of the ossification enter. Chemical signals cause the cells of the mesenchyme to cluster and differentiate into first osteoprogenitor cells, and then into osteoblasts. Osteoblasts secrete the organic ECM of bone until they are surrounded by it. 2) Calcification: secretion of ECM stops, and the cells, now called osteocytes lie in lacunae and extend their narrow cytoplasmic processes into canalicili that radiate in all directions. Within a few days, the calcium and other mineral salts are deposited in ECM and harden. 3) Formation of trabeculae: the bone ECM forms and develops into trabeculae that fuse with one another to form spongy bone around the network of blood vessels in the tissue. CT associated with blood vessels in trabeculae differentiate into red bone marrow. 4) Development of the periosteum: Mesenchyme condenses at the periphery of the bone and develops into periosteum. Eventually, thin layer of compact bone replaces the surface layers of the spongy bone, but spongy bone remains in the center. Endochondral ossification: bone forms within hyaline cartilage that develops from mesenchyme. Most bones of the body are formed this way. Process is best observed in a long bone. Steps: 1) Development of cartilage model: chemical messages cause the cells in mesenchyme to crowd together in the general shape of the future bone, and then develop into chondroblasts secrete cartilage extracellular matrix, producing a cartilage model consisting of hyaline cartilage. A covering called the perichondrium develops around the cartilage model. 2) Growth of the cartilage model: Once chondroblasts become deeply buried in the cartilage ECM. The cartilage model grows in length by continual cell division of chondrocytes, accompanied by further secretion of the cartilage ECM. This type of growth is known as interstitial growth results in an increase in length. New chondroblasts that develop from the perichondrium is responsible for the growth of the cartilage in thickness. This process is called appositional growth. Calcification begins to occur as cartilage model continue to grow. Other chondrocytes within the calcifying cartilage begin to die because nutrients can no longer diffuse quickly enough through the extracellular matrix. As they die, the spaces left behind merge into small cavities called lacunae. 3) Development of primary ossification center: proceeds inward from the external surface of the bone. A nutrient artery penetrates the perichondrium and the calcifying cartilage model through a nutrient foramen in the midregion of the cartilage model, stimulating osteoprogenitors in the perichondrium to differentiate into osteoblasts. Once perichondrium starts to form bone, it is known as periosteum. Periosteal capillaries grow into the disintegrating calcified cartilage, which in turn induces growth of a primary ossification center. Osteoblasts then begin to deposit bone ECM over remnants of calcified cartilage which forms spongy bone trabeculae. Primary ossif. spreads from this central canal to both ends of the cartilage model 4) Development of the medullary cavity: As primary ossif. center grows toward ends of the bone, osteoclasts break down some of the new spongy bone. As a result, a cavity is formed. 5) Development of the secondary ossification centers: develops usually around the time of birth. Spongy bone remains in the interior of epiphysis so no medullary cavity. It proceeds outward from the center of the epiphysis toward the OUTER surface of the bone. 6) Formation of articular cartilage and the epiphyseal growth plate: Hyaline that covers the epiphysis becomes articular cartilage.

Which microscopic structure is found only in the cardiac muscle tissue?

Intercalated discs

Initial formation of the frontal bone is done through which type of ossification?

Intramembranous

After the fusion of myoblasts, the muscle fiber loses its ability to:

Go through mitosis

This muscle is innervated by the trigeminal nerve

Masseter

Sensory tracts carry information to the brain

Motor tracts carry information away from the brain

What kind of bone is the vertebral disc?

An irregular one

Describe the process that transport substances across the plasma membrane

Passive Transport: Movement of substances down a concentration gradient until equilibrium is reached; do not require cellular energy in the form of ATP. Simple Diffusion: Passive movement of a substance down its concentration gradient through the lipid bilayer of the plasma membrane without the help of membrane transport proteins. Substances transported: Nonpolar, hydrophobic solutes: oxygen, carbon dioxide, and nitrogen gases; fatty acids; steroids; and fat-soluble vitamins. Polar molecules such as water, urea, and small alcohols. Channel-Mediated Facilitated Diffusion: a solute moves down its concentration gradient across the lipid bilayer through a membrane channel. Most membrane channels are ion channels, integral transmembrane proteins that allow passage of small, inorganic ions that are too hydrophilic to penetrate the nonpolar interior of the lipid bilayer. Each ion can diffuse across the membrane only at certain sites. In typical plasma membranes, the most numerous ion channels are selective for K+ (potassium ions) or Cl− (chloride ions); fewer channels are available for Na+ (sodium ions) or Ca2+ (calcium ions). Diffusion of ions through channels is generally slower than free diffusion through the lipid bilayer because channels occupy a smaller fraction of the membrane's total surface area than lipids. Still, facilitated diffusion through channels is a very fast process: More than a million potassium ions can flow through a K+ channel in one second! Carrier-Mediated Facilitated Diffusion: In carrier-mediated facilitated diffusion, a carrier (also called a transporter) moves a solute down its concentration gradient across the plasma membrane. Since this is a passive process, no cellular energy is required. The solute binds to a specific carrier on one side of the membrane and is released on the other side after the carrier undergoes a change in shape. The solute binds more often to the carrier on the side of the membrane with a higher concentration of solute. Once the concentration is the same on both sides of the membrane, solute molecules bind to the carrier on the cytosolic side and move out to the extracellular fluid as rapidly as they bind to the carrier on the extracellular side and move into the cytosol. The rate of carrier-mediated facilitated diffusion (how quickly it occurs) is determined by the steepness of the concentration gradient across the membrane. Osmosis: Passive movement of water molecules across a selectively permeable membrane from an area of higher to lower water concentration until equilibrium is reached. Substances transported: solvent water in living systems *** If the solute concentration is greater inside of the cell than outside the cell, water will move by osmosis Active Transport: Active process in which a cell expends energy to move a substance across the membrane against its concentration gradient by transmembrane proteins that function as carriers. Transports polar or charged solutes. Primary Active Transport: Active process in which a substance moves across the membrane against its concentration gradient by pumps (carriers) that use energy supplied by hydrolysis of ATP. Transports Na+, K+, Ca2+, H+, I−, Cl−, and other ions. Secondary Active Transport: Coupled active transport of two substances across the membrane using energy supplied by a Na+ or H+ concentration gradient maintained by primary active transport pumps. Antiporters move Na+ (or H+) and another substance in opposite directions across the membrane; symporters move Na+ (or H+) and another substance in the same direction across the membrane. Substances transported: Antiport: Ca2+, H+ out of cells. Symport: glucose, amino acids into cells. Receptor-Mediated Endocytosis: Ligand-receptor complexes trigger infolding of a clathrin-coated pit that forms a vesicle containing ligands. Substances transported: Ligands: transferrin, low-density lipoproteins. (LDLs), some vitamins, certain hormones, and antibodies. Phagocytosis: Bulk-Phase Endocytosis: Cell drinking"; movement of extracellular fluid into a cell by infolding of plasma membrane to form a vesicle. Substances include solutes in extracellular fluid Exocytosis: Movement of substances out of a cell in secretory vesicles that fuse with the plasma membrane and release their contents into the extracellular fluid. Substances include neurotransmitters, hormones, and digestive enzymes Transcytosis: Movement of a substance through a cell as a result of endocytosis on one side and exocytosis on the opposite side. Substance such as antibodies, across endothelial cells. This is a common route for substances to pass between blood plasma and interstitial fluid

The median nerve, if damaged, can cause:

Numbness, tingiling, and pain in the palm and fingers.

Foramen

Opening or hole

Describe the origin, insertion, action, and nerves of major skeletal muscles

Rectus Abdominis: Origin- is pubic crest and pubic symphysis. Insertion- is cartilage of ribs 5-7 and xiphoid process. Action- is that it flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column. Innervation- Thoracic spinal nerves T7-T12. Pectoralis Major: Origin- Clavicle (clavicular head), sternum, and costal cartilages of ribs 2-6 and sometimes ribs 1-7 (sternocostal head). Insertion- Greater tubercle and lateral lip of intertubercular sulcus of humerus. Action- As a whole, adducts and medially rotates arm at shoulder joint; clavicular head flexes arm, and sternocostal head extends flexed arm to side of trunk. Innervation- Medial and lateral pectoral nerves. Latissimus Dorsi Origin-Spines of T7-L5, lumbar vertebrae, crests of sacrum and ilium, ribs 9-12 via thoracolumbar fascia. Insertion- Intertubercular sulcus of humerus. Action- Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly. RMA: Elevates vertebral column and torso. Innervation- Thoracodorsal nerve. Deltoid Origin- Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of scapula (posterior fibers). Insertion- Deltoid tuberosity of humerus. Action- Lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially rotate arm at shoulder joint; posterior fibers extend and laterally rotate arm at shoulder joint. Innervation- Axillary nerve. Trapezius Origin-Superior nuchal line of occipital bone, ligamentum nuchae, and spines of C7-T12. Insertion- Clavicle and acromion and spine of scapula. Action- Superior fibers upward rotate scapula; middle fibers adduct scapula; inferior fibers depress and upward rotate scapula; superior and inferior fibers together rotate scapula upward; stabilizes scapula. RMA: Superior fibers can help extend head. Innervation- Accessory (XI) nerve and cervical spinal nerves C3-C5. Rhomboideus Major Origin- Spines of T2-T5. Insertion- Vertebral border of scapula inferior to spine. Action- Elevates and adducts scapula and rotates it downward; stabilizes scapula. Innervation- Dorsal scapular nerve. Supraspinatus Origin- Supraspinous fossa of scapula. Insertion- Greater tubercle of humerus. Action- Assists deltoid muscle in abducting arm at shoulder joint. Innervation- Suprascapular nerve. Infraspinatus Origin- Infraspinous fossa of scapula. Insertion- Greater tubercle of humerus. Action- Laterally rotates arm at shoulder joint. Innervation- Suprascapular nerve. Teres Minor Origin- Inferior lateral border of scapula. Insertion- Greater tubercle of humerus. Action- Laterally rotates and extends arm at shoulder joint. Innervation- Axillary nerve. Subscapularis Origin- Subscapular fossa of scapula. Insertion- Lesser tubercle of humerus. Action- Medially rotates arm at shoulder joint. Innervation- Upper and lower subscapular nerve. Biceps Brachii Origin- Long head originates from tubercle above glenoid cavity of scapula (supraglenoid tubercle).Short head originates from coracoid process of scapula. Insertion- Radial tuberosity of radius and bicipital aponeurosis.* Action-Flexes forearm at elbow joint, supinates forearm at radioulnar joints, and flexes arm at shoulder joint. Innervation- Musculocutaneous nerve. Triceps Brachii Origin- Long head originates from infraglenoid tubercle, a projection inferior to glenoid cavity of scapula.Lateral head originates from lateral and posterior surface of humerus.Medial head originates from entire posterior surface of humerus inferior to a groove for the radial nerve. Insertion- Olecranon of ulna. Action- Extends forearm at elbow joint and extends arm at shoulder joint. Innervation- Radial nerve. Brachioradialis Origin- Lateral border of distal end of humerus. Insertion- Superior to styloid process of radius. Action- Flexes forearm at elbow joint; supinates and pronates forearm at radioulnar joints to neutral position. Innervation- Radial nerve. Gluteus Medius Origin- Ilium. Insertion- Greater trochanter of femur. Action- Abducts thigh at hip joint and medially rotates thigh. Innervation- Superior gluteal nerve. Rectus Femoris Origin- two sites on the illium; the anterior inferior iliac spine and supraacetabular groove Insertion- tuberosity of the tibia Action- Only muscle that can flex the hip. Innervation- femoral nerve Vastus Lateralis Origin-Ischial tuberosity Insertion-Head of fibula Action- Rotates lower leg to point foot laterally Innervation- lumbar and sacral plexuses Vastus Intermedius Origin-Ischial tuberosity Insertion-Head of fibula Action-Rotates lower leg to point foot laterally Innervation- lumbar and sacral plexuses Vastus Medialis Origin-Ischial tuberosity Insertion-Head of fibula Action-Rotates lower leg to point foot laterally Innervation-lumbar and sacral plexuses Biceps Femoris Origin-Long head arises from ischial tuberosity; short head arises from linea aspera of femur. Insertion-Head of fibula and lateral condyle of tibia. Action-Flexes leg at knee joint and extends thigh at hip joint. Innervation-Tibial and fibular nerves from sciatic nerve. Semitendinosus Origin- Ischial tuberosity. Insertion- Proximal part of medial surface of shaft of tibia. Action-Flexes leg at knee joint and extends thigh at hip joint. Innervation-Tibial nerve from sciatic nerve. Semimembranosus Origin- Ischial tuberosity. Insertion-Medial condyle of tibia. Action-Flexes leg at knee joint and extends thigh at hip joint. Innervation-Tibial nerve from sciatic nerve. Tibialis Anterior Origin- Lateral condyle and body of tibia and interosseous membrane (sheet of fibrous tissue that holds shafts of tibia and fibula together). Insertion- Metatarsal I and first (medial) cuneiform. Action- Dorsiflexes foot at ankle joint and inverts (supinates) foot at intertarsal joints. Innervation- Deep fibular (peroneal) nerve. Gastrocnemius Origin- Lateral and medial condyles of femur and capsule of knee. Insertion- Calcaneus by way of calcaneal (Achilles) tendon. Action- Plantar flexes foot at ankle joint and flexes leg at knee joint. Innervation- Tibial nerve.

Evaluation of which brain waves might indicate a brain injury in an awake adult?

delta waves

Compare and contrast cervical, thoracic, and lumbar vertebrae.

There are 7 cervical vertebrae, 12 thoracic, 5 lumbar, 1 sacrum (five fused sacral vertebrae), and 1 coccyx (four fused coccygeal vertebrae). The cervical, thoracic, and lumbar vertebrae are movable, but the sacrum and coccyx are not.

Describe the principal surface markings on bones and the functions of each.

There are two major types of surface markings: (1) depressions and openings, which allow the passage of soft tissues (such as blood vessels, nerves, ligaments, and tendons) or form joints, and (2) processes, projections or outgrowths that either help form joints or serve as attachment points for connective tissue (such as ligaments and tendons).

Describe how skin contributes to the regulation of body temperature, storage of blood, protection, sensation, excretion and absorption, and synthesis of vitamin D

Thermoregulation: Recall that thermoregulation is the homeostatic regulation of body temperature. The skin contributes to thermoregulation in two ways: by liberating sweat at its surface and by adjusting the flow of blood in the dermis. In response to high environmental temperature or heat produced by exercise, sweat production from eccrine sweat glands increases; the evaporation of sweat from the skin surface helps lower body temperature. In addition, blood vessels in the dermis of the skin dilate (become wider); consequently, more blood flows through the dermis, which increases the amount of heat loss from the body (see Figure 25.19. In response to low environmental temperature, production of sweat from eccrine sweat glands is decreased, which helps conserve heat. Also, the blood vessels in the dermis of the skin constrict (become narrow), which decreases blood flow through the skin and reduces heat loss from the body. And, skeletal muscle contractions generate body heat. Blood reservoir: The dermis houses an extensive network of blood vessels that carry 8-10% of the total blood flow in a resting adult. For this reason, the skin acts as a blood reservoir. Protection: The skin provides protection to the body in various ways. Keratin protects underlying tissues from microbes, abrasion, heat, and chemicals, and the tightly interlocked keratinocytes resist invasion by microbes. Lipids released by lamellar granules inhibit evaporation of water from the skin surface, thus guarding against dehydration; they also retard entry of water across the skin surface during showers and swims. The oily sebum from the sebaceous glands keeps skin and hairs from drying out and contains bactericidal chemicals (substances that kill bacteria). The acidic pH of perspiration retards the growth of some microbes. The pigment melanin helps shield against the damaging effects of ultraviolet light. Two types of cells carry out protective functions that are immunological in nature. Intraepidermal macrophages alert the immune system to the presence of potentially harmful microbial invaders by recognizing and processing them, and macrophages in the dermis phagocytize bacteria and viruses that manage to bypass the intraepidermal macrophages of the epidermis. Cutaneous Sensations: Cutaneous sensations are sensations that arise in the skin, including tactile sensations—touch, pressure, vibration, and tickling—as well as thermal sensations such as warmth and coolness. Another cutaneous sensation, pain, usually is an indication of impending or actual tissue damage. There is a wide variety of nerve endings and receptors distributed throughout the skin, including the tactile discs of the epidermis, the corpuscles of touch in the dermis, and hair root plexuses around each hair follicle. Chapter 16 provides more details on the topic of cutaneous sensations. Excretion and Absorption: The skin normally has a small role in excretion, the elimination of substances from the body, and absorption, the passage of materials from the external environment into body cells. Despite the almost waterproof nature of the stratum corneum, about 400 mL of water evaporates through it daily. A sedentary person loses an additional 200 mL per day as sweat; a physically active person loses much more. Besides removing water and heat from the body, sweat also is the vehicle for excretion of small amounts of salts, carbon dioxide, and two organic molecules that result from the breakdown of proteins—ammonia and urea. The absorption of water-soluble substances through the skin is negligible, but certain lipid-soluble materials do penetrate the skin. These include fat-soluble vitamins (A, D, E, and K), certain drugs, and the gases oxygen and carbon dioxide. Toxic materials that can be absorbed through the skin include organic solvents such as acetone (in some nail polish removers) and carbon tetrachloride (dry-cleaning fluid); salts of heavy metals such as lead, mercury, and arsenic; and the substances in poison ivy and poison oak. Since topical (applied to the skin) steroids, such as cortisone, are lipid-soluble, they move easily into the papillary region of the dermis. Here, they exert their antiinflammatory properties by inhibiting histamine production by mast cells (recall that histamine contributes to inflammation). Certain drugs that are absorbed by the skin may be administered by applying adhesive patches to the skin. Synthesis of Vitamin D: Synthesis of vitamin D requires activation of a precursor molecule in the skin by ultraviolet (UV) rays in sunlight. Enzymes in the liver and kidneys then modify the activated molecule, finally producing calcitriol, the most active form of vitamin D. Calcitriol is a hormone that aids in the absorption of calcium from foods in the gastrointestinal tract into the blood. Only a small amount of exposure to UV light (about 10 to 15 minutes at least twice a week) is required for vitamin D synthesis. People who avoid sun exposure and individuals who live in colder, northern climates may require vitamin D supplements to avoid vitamin D deficiency. Most cells of the immune system have vitamin D receptors, and the cells activate vitamin D in response to an infection, especially a respiratory infection, such as influenza. Vitamin D is believed to enhance phagocytic activity, increase the production of antimicrobial substances in phagocytes, regulate immune functions, and help reduce inflammation.

Explain the cause of rigor mortis

This happens after death. Cellular membranes become leaky and calcium ions leak out of the sarcoplasmic reticulum into the sarcoplasm which results in myosin heads binding to actin. ATP synthesis ceases pretty much right after breathing stops--this means that the cross bridges cannot detach from the actin. Muscles become in a state of rigidity. It begins 3-4 hours after death and lasts about 24 hours. it stops because proteolytic enzymes from lysosomes digest the cross-bridges.

Winged scapula

is NOT the result of a nerve that affects the interosseous muscle

Direction of fibers

rectus -- parallel to midline ex: rectus abdominis transverse--perpedicular to midline ex: transverse abdomonis oblique--diagonal to midline--external oblique

Crest

ridge

Which area is responsible for the head and eye movement in response to visual stimuli?

Superior colliculus

The tibial nerve would be involved with:

A dance performing a pointe (standing on toes)

What type of bone is the frontal bone

A flat bone

What kind of bone is the trapezoid?

A short bone

Spinal nerve C8 exits between which two vertebrae?

C7-T1

Describe the body's six levels of structural organization

Chemical: This very basic level can be compared to the letters of the alphabet and includes atoms, the smallest units of matter that participate in chemical reactions, and molecules, two or more atoms joined together. Certain atoms, such as carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), calcium (Ca), and sulfur (S), are essential for maintaining life. Two familiar molecules found in the body are deoxyribonucleic acid (DNA), the genetic material passed from one generation to the next, and glucose, commonly known as blood sugar. Cellular: Molecules combine to form cells, the basic structural and functional units of an organism that are composed of chemicals. Just as words are the smallest elements of language that make sense, cells are the smallest living units in the human body. Among the many kinds of cells in your body are muscle cells, nerve cells, and epithelial cells. Figure 1.1 shows a smooth muscle cell, one of the three types of muscle cells in the body. Tissue: Tissues are groups of cells and the materials surrounding them that work together to perform a particular function, similar to the way words are put together to form sentences. There are just four basic types of tissues in your body: epithelial tissue, connective tissue, muscular tissue, and nervous tissue. Epithelial tissue covers body surfaces, lines hollow organs and cavities, and forms glands. Connective tissue connects, supports, and protects body organs while distributing blood vessels to other tissues. Muscular tissue contracts to make body parts move and generates heat. Nervous tissue carries information from one part of the body to another through nerve impulses. Organ: At the organ level, different types of tissues are joined together. Similar to the relationship between sentences and paragraphs, organs are structures that are composed of two or more different types of tissues; they have specific functions and usually have recognizable shapes. Examples of organs are the stomach, skin, bones, heart, liver, lungs, and brain. The stomach's outer covering is a layer of epithelial tissue and connective tissue that reduces friction when the stomach moves and rubs against other organs. Underneath are three layers of a type of muscular tissue called smooth muscle tissue, which contracts to churn and mix food and then push it into the next digestive organ, the small intestine. The innermost lining is an epithelial tissue layer that produces fluid and chemicals responsible for digestion in the stomach. System: A system (or chapter, in our language analogy) consists of related organs (paragraphs) with a common function. An example of the system level, also called the organ-system level, is the digestive system, which breaks down and absorbs food. Its organs include the mouth, salivary glands, pharynx (throat), esophagus (food tube), stomach, small intestine, large intestine, liver, gallbladder, and pancreas. Sometimes an organ is part of more than one system. The pancreas, for example, is part of both the digestive system and the hormone-producing endocrine system. Organismal: An organism, any living individual, can be compared to a book in our analogy. All the parts of the human body functioning together constitute the total organism.

Sulcus

Grove

What term best describes this surface marking?

Meatus

Fissure

Narrow slit

Recall the functional organization of the cerebral cortex

Primary somatosensory: located directly posterior to the central sulcus of each cerebral hemisphere in the postcentral gyrus of each parietal lobe. It extends from the lateral cerebral sulcus, along the lateral surface of the parietal lobe to the longitudinal fissure, and then along the medial surface of the parietal lobe within the longitudinal fissure. The primary somatosensory area receives nerve impulses for touch, pressure, vibration, itch, tickle, temperature (coldness and warmth), pain, and proprioception (joint and muscle position) and is involved in the perception of these somatic sensations. A "map" of the entire body is present in the primary somatosensory area: Each point within the area receives impulses from a specific part of the body. The size of the cortical area receiving impulses from a particular part of the body depends on the number of receptors present there rather than on the size of the body part. For example, a larger region of the somatosensory area receives impulses from the lips and fingertips than from the thorax or hip. This distorted somatic sensory map of the body is known as the sensory homunculus (homunculus = little man). The primary somatosensory area allows you to pinpoint where somatic sensations originate, so that you know exactly where on your body to swat that mosquito. Primary gustatory: located in the insula, receives impulses for taste and is involved in gustatory perception and taste discrimination. Primary visual: located at the posterior tip of the occipital lobe mainly on the medial surface, receives visual information and is involved in visual perception. Primary auditory: located in the superior part of the temporal lobe near the lateral cerebral sulcus, receives information for sound and is involved in auditory perception. Primary motor: is located in the precentral gyrus of the frontal lobe. As is true for the primary somatosensory area, a "map" of the entire body is present in the primary motor area: Each region within the area controls voluntary contractions of specific muscles or groups of muscles (see Figure 16.8b). Electrical stimulation of any point in the primary motor area causes contraction of specific skeletal muscle fibers on the opposite side of the body. Different muscles are represented unequally in the primary motor area. More cortical area is devoted to those muscles involved in skilled, complex, or delicate movement. For instance, the cortical region devoted to muscles that move the fingers is much larger than the region for muscles that move the toes. This distorted muscle map of the body is called the motor homunculus. Broca's Somatosensory: located in the frontal lobe close to the lateral cerebral sulcus. Speaking and understanding language are complex activities that involve several sensory, association, and motor areas of the cortex. In about 97% of the population, these language areas are localized in the left hemisphere. The planning and production of speech occur in the left frontal lobe in most people. From Broca's speech area, nerve impulses pass to the premotor regions that control the muscles of the larynx, pharynx, and mouth. The impulses from the premotor area result in specific, coordinated muscle contractions. Simultaneously, impulses propagate from Broca's speech area to the primary motor area. From here, impulses also control the breathing muscles to regulate the proper flow of air past the vocal cords. The coordinated contractions of your speech and breathing muscles enable you to speak your thoughts. People who suffer a cerebrovascular accident (CVA) or stroke in this area can still have clear thoughts but are unable to form words, a phenomenon referred to as nonfluent aphasia Wernicke's, visual association: a broad region in the left temporal and parietal lobes, interprets the meaning of speech by recognizing spoken words. It is active as you translate words into thoughts. The regions in the right hemisphere that correspond to Broca's and Wernicke's areas in the left hemisphere also contribute to verbal communication by adding emotional content, such as anger or joy, to spoken words. Unlike those who have CVAs in Broca's area, people who suffer strokes in Wernicke's area can still speak, but cannot arrange words in a coherent fashion (fluent aphasia, or "word salad").

Identify the five primary tastes

Salty, sour, sweet, bitter, and umami

Fossa

Shallow depression

Describe the process of four important spinal reflexes

Stretch reflex: causes contraction of a skeletal muscle in response to stretching of the muscle. This type of reflex occurs via a monosynaptic reflex arc. The reflex can occur by activation of a single sensory neuron that forms one synapse in the CNS with a single motor neuron. Stretch reflexes can be elicited by tapping on tendons attached to muscles at the elbow, wrist, knee, and ankle joints. Example: patellar reflex (knee jerk) **In a stretch reflex, muscles spindles detect the muscle stretch. A somatic sensory neuron sends signals to motor neurons in the anterior gray horn and to inhibitory interneuron in the integrating center. This stretch reflex primary motor path would be classified as ipsilateral. This primary pathway excites the effector muscle and inhibits the antagonist muscle. Tendon reflex: The stretch reflex operates as a feedback mechanism to control muscle length by causing muscle contraction. In contrast, the tendon reflex operates as a feedback mechanism to control muscle tension by causing muscle relaxation before muscle force becomes so great that tendons might be torn. Although the tendon reflex is less sensitive than the stretch reflex, it can override the stretch reflex when tension is great, making you drop a very heavy weight, for example. Like the stretch reflex, the tendon reflex is ipsilateral. The sensory receptors for this reflex are called tendon organs, which lie within a tendon near its junction with a muscle. In contrast to muscle spindles, which are sensitive to changes in muscle length, tendon organs detect and respond to changes in muscle tension that are caused by passive stretch or muscular contraction. Flexor (withdrawal) reflex: Another reflex involving a polysynaptic reflex arc results when, for instance, you step on a tack. In response to such a painful stimulus, you immediately withdraw your leg. This reflex, called the flexor reflex or withdrawal reflex, operates as follows: 1) Stepping on a tack stimulates the dendrites (sensory receptor) of a pain-sensitive neuron. 2)This sensory neuron then generates nerve impulses, which propagate into the spinal cord. 3)Within the spinal cord (integrating center), the sensory neuron activates interneurons that extend to several spinal cord segments. 4)The interneurons activate motor neurons in several spinal cord segments. As a result, the motor neurons generate nerve impulses, which propagate toward the axon terminals. 5)Acetylcholine released by the motor neurons causes the flexor muscles in the thigh (effectors) to contract, producing withdrawal of the leg. This reflex is protective because contraction of flexor muscles moves a limb away from the source of a possibly damaging stimulus. Crossed extensor reflex: Something else may happen when you step on a tack: You may start to lose your balance as your body weight shifts to the other foot. Besides initiating the flexor reflex that causes you to withdraw the limb, the pain impulses from stepping on the tack also initiate a crossed extensor reflex to help you maintain your balance; it operates as follows: 1) Stepping on a tack stimulates the sensory receptor of a pain-sensitive neuron in the right foot. 2) This sensory neuron then generates nerve impulses, which propagate into the spinal cord. 3)Within the spinal cord (integrating center), the sensory neuron activates several interneurons that synapse with motor neurons on the left side of the spinal cord in several spinal cord segments. Thus, incoming pain signals cross to the opposite side through interneurons at that level, and at several levels above and below the point of entry into the spinal cord. 4)The interneurons excite motor neurons in several spinal cord segments that innervate extensor muscles. The motor neurons in turn generate more nerve impulses, which propagate toward the axon terminals. 5)Acetylcholine released by the motor neurons causes extensor muscles in the thigh (effectors) of the unstimulated left limb to contract, producing extension of the left leg. In this way, weight can be placed on the foot that must now support the entire body. A comparable reflex occurs with painful stimulation of the left lower limb or either upper limb. *** The crossed-extensor reflex integrating center is polysynaptic since several sensory neurons synapse with interneurons that synapse with motor neurons. The interneurons excite motor neurons in several segments which is known as a intersegmental reflex arc reflex. This is a contralateral reflex arc since the motor information exits the opposite side of the body from the sensory input. At the neuromuscular junction, acetylcholine is released to excite the muscle that will extend.

Trochanter

Very large projection

Describe osteoblasts:

-Bone building cells. -Active when blood calcium levels are high. -PTH causes these cells to become more active -Differentiates from osteoprogenitor -Overactivity can cause hypocalcemia

Describe the structure and function of each part of a long bone.

-Epiphysis: proximal and distal ends of the bone. -Metaphysis: the regions between the diaphysis and epiphysis. In a growing bone, each metaphysis contains an epiphyseal (growth) plate (made of hyaline cartilage) which allows the bone to grow in length. It is then replaced by epiphyseal line when the cartilage turns to bone. -Diaphysis: the bone's shaft/body - the long cylindrical main part of the bone. -Articular cartilage: Thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms an articulation with another bone. It also reduces friction and absorbs shock at freely movable joints. Repair of damage is limited because articular cartilage lacks a perichondrium and lacks blood vessels. -Endosteum: a thin membrane that lines the medullary cavity. it contains a single layer of bone-forming cells and a small amount of connective tissue -Medullary cavity: hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow and numerous blood vessels in adults. This reduces the dense bony material where it is needed least. The long bones tubular designs provides max strength and min weight -Periosteum: A tough connective tissue sheath and its associated blood supply that surrounds the bone surface wherever it is not covered by articular cartilage. Composed of an outer fibrous layer of dense irregular connective tissue and an inner osteogenic layer that consists of cells. Some of the cells enable bone to grow in thickness, but not in length. It also protects the bone and assists in fx repair. it serves as an attachment point for ligaments and tendons. The periosteum is attached to underlying bone by perforating fibers (sharpays fibers) thick bundles of collagen.

Compare the principal differences between female and male pelves.

-False pelvis: Female: Shallow Male: Deep -Pelvic brim: F: wide and more oval. M: narrow and heart-shaped -Pubic arch: F: Greater than 90 degrees. M: Less than 90 degrees -Greater sciatic notch: F: Wide, almost 90 degrees. M: Narrow about 70 degrees inverted V -Pelvic outlet: F: wider. M: narrower.

Describe the structural and functional features of the bones in the vertebral column.

-Foramina: Cervical has one vertebral and two transverse. Thoracic and lumbar has one vertebral. -Spinous process: Cervical is slender, often bifid (C2-C6). Thoracic is long, fairly thick (most projected inferiorly) and lumbar has a short, blunt one that projects posteriorly. -Transverse processes: Cervical is small, thoracic is fairly large, and lumbar is large and blunt. -Articular facets: Cervical is absent, thoracic is present, and lumbar is absent. -Intervertebral discs: Cervical are thick relative to size of vertebral bodies. Thoracic is thin relative to size of vertebral bodies. Lumbar is thickest. -Nucleus pulposus and annulus fibrosus: Intervertebral discs are found between the bodies of adjacent vertebrae from the second cervical vertebra to the sacrum and account for about 25% of the height of the vertebral column. Each disc has an outer fibrous ring consisting of fibrocartilage called the annulus fibrosus (annulus = ringlike) and an inner soft, pulpy, highly elastic substance called the nucleus pulposus.

Classify bones based on their shape (using key examples from class)

-Long: Greater length than width and consist of a shaft and a variable number of extremities or ends and slightly curved for strength. Consists mostly of compact bone in diaphyses but lots of spongy bone on the ends. (e.g. femur, tibia, fibula, ulna, radius, phalanges) -Short: somewhat cube shaped and nearly equal in length and width. They consist of spongy bone tissue except at the surface, which has a thin layer of compact bone. (e.g. most carpal and tarsal bones) -Flat: Generally thin and composed of two parallel plates of compact bone tissue enclosing a layer of spongy tissue. Provides area for muscle attachment and stability. (e.g. cranial bones, sternum, ribs, thorax, scapulae. -Irregular: Complex in shape. They vary in spongy to compact ratio. (e.g. backbones, hip, certain facial bones, and calcaneus) -Sesamoid: Shaped like a sesame seed and develop in certain tendons where there are considerable friction, tension, and physical stress, such as the palms and soles. Typically measure only a few mm in diameter (with exception of knee cap). They are not always completely ossified. They protect tendons from excessive wear and tear, and they often change the direction of pull of a tendon which improves mechanical advantage of joint.

Describe several common types of fractures.

-Open (compound): The broken ends of the bone protrude through the skin. Conversely, a closed (simple) fracture does not break -Comminuted: The bone is splintered, crushed, or broken into pieces at the site of impact, and smaller bone fragments lie between the two main fragments. -Greenstick: A partial fracture in which one side of the bone is broken and the other side bends; similar to the way a green twig breaks on one side while the other side stays whole, but bends; occurs only in children, whose bones are not fully ossified and contain more organic material than inorganic material. -Impacted: One end of the fractured bone is forcefully driven into the interior of the other. -Pott: Fracture of the distal end of the lateral leg bone (fibula), with serious injury of the distal tibial articulation. -Colles: Fracture of the distal end of the lateral forearm bone (radius) in which the distal fragment is displaced posteriorly.

Describe the cellular composition of bone tissue and the function of each type of cell.

-Osteoprogenitor cells: Unspecialized bone stem cells derived from mesenchyme. Only bone cells to undergo cell division. the resulting cells develop into osteoblasts. Osteoprogenitor cells are found along the inner portion of the periosteum, in the endosteum, and in the canals within bone that contain blood vessels. -Osteoblasts: Bone building cells. They synthesize and secrete collagen fibers and other organic components needed to make ECM. They initiate calcification. As osteoblasts surround themselves with ECM, they become trapped in their secretions and become osteocytes. Osteocytes: Mature bone cells, are the main cells in bone tissue and maintain its daily metabolism, such as the exchange of nutrients and waste within the blood. They do not undergo cell division Osteoclasts: Huge cells derived from the fusion of many monocytes and are concentrated in the endosteum. On the side of the cell that faces the bone surface, the osteoclast;s plasma membrane is deeply folded in ruffle fashion. Here the cells releases lysosomal enzymes and acids that digest protein and mineral components of underlying ECM. This breakdown is termed bone resorption. It is part of normal development. Osteoclasts also help regulate blood calcium levels.

Spinal nerves

-Part of the PNS -Connect the CNS to sensory receptors and effectors in all parts of the body. -Named according to the region of the vertebral column from which they emerge -Are mixed nerves

Describe common disorders of the axial skeleton

-Scoliosis:the most common of abnormal curves, it is the lateral bending of the vertebral column usually in the thoracic region. It may result from congenitally malformed vertebrae, chronic sciatica, and paralysis of muscles on one side of the vertebral column, poor posture, or one leg being shorter than the other. -Kyphosis: An increase in the thoracic curve of the vertebral column that produces a hunchback look. In TB of the spine, vertebral bodies may partially collapse, which causes an acute angular bending of the vertebral column. In the elderly, degeneration of the intervertebral disc lead to kyphosis. It can also be caused by rickets and poor posture. Common in females with advanced osteoporosis. -Lordosis: An increase in the lumbar curve of the vertebral column. May result from increased weight of the abdomen as in pregnancy or obesity, poor posture, rickets, osteoporosis or TB of spine. -Herniated disc: When the nucleus pulposus may herniate (protrude) posteriorly as a result of pressure or weakening of the discs that may be great enough to rupture the surrounding fibrocartilage or into one of the adjacent vertebral bodies

Describe the structure and functions of the three types of fibrous joints.

-Sutures: a fibrous joint composed of a thin layer of dense irregular connective tissue. They only occur between the bones of the skull. The irregular interlocking edges of sutures give them added strength. They are immovable (in adults) or slightly movable (in children). They play an important role in shock absorption. Some sutures are even replaced by bone in adults. These are referred to as synostosis or bony joint. **** The lambdoid suture articulates with the most bones in the skull -Syndesmoses: A joint in which there is greater distance between the articulating surfaces and more dense irregular connective tissue than in a suture. The dense irregular CT is typically arranged as a bundle (ligament), allowing the joint to permit limited movement. An example of this is the distal tibiofibular joint, where the anterior tibiofibular ligament connects the tibia and fibula. It permits slight movement (amphiarthrosis). Another example of syndesmosis is called gomphosis or dentoalveolar joint in which a cone shaped peg fits into a socket. The only examples of gomphoses in the human body are the articulations between the roots and the teeth and their sockets in the alveolar processes in the maxillae and mandible. A healthy gomphosis permits minute shock absorbing movements (amphiarthrosis) -Interosseous membranes: a substantial sheet of dense irregular CT that binds neighboring long bones and permits slight movement (amphiarthrosis) The two main IM joints in the body: one between the radius and the ulna and the other occurs between the tibia and the fibula. These strong CT sheets help hold these adjacent long bones together as well as define range of motion between the neighboring bones and provide increased attachment surface for muscles that produce movements of the digits of the hand and foot.

Describe the functional classification of joints.

-Synarthroses: An immovable joint. -Amphiarthroses: A slightly movable joint. -Diarthroses: A freely movable joint. All diarthroses are synovial joints. They have a variety of shapes and permit several different types of movement.

Describe how muscle action potentials arise at the neuromuscular junction. (see Figure 10.9 + 10.7)

1) A nerve impulse elicits a muscle action potential by first releasing Ach. A nerve impulse at the synaptic end bulbs stimulates the opening of voltage gated channels. Ca flows inward through the open channels. This stimulates the synaptic vesicles to undergo exocytosis. The synaptic vesicles then fuse with the motor neuron's plasma membrane which liberates Ach into synaptic cleft. It then diffuses across the synaptic cleft between the motor neuron and the motor end plate. 2) The binding of two molecules of Ach to the receptor on the motor end plates opens an ion channel in the Ach receptor. One open, small cations (mostly Na+) can flow across the membrane. 3) This next step details the production of muscle action potential. The inflow of Na+ makes the inside of the muscle fiber more + charged. This triggers a muscle action potential. Each nerve impulse normally elicits one muscle action potential. The muscle action potential then propagates along the sarcolemma into the system of T tubules. This causes stored Ca in the SR to release into sarcoplasm, which leads to contraction of the muscle fiber. 4) The final step is the termination of Ach activity. The effect of Ach binding lasts only for a short time because it is quickly broken down by enzyme AchE (which is located on the EC side of the motor end plate membrane) AchE breaks down Ach into acetate and choline -- these products can NOT activate the Ach receptor. *******The action potential depolarizes the synaptic end bulb, which causes openings of the voltage gates. The influx of calcium ions causes exocytosis of Ach. The neurotransmitter attaches to ligand gates. Opening of the channel allows an influx of sodium ions.

Outline the steps involved in the sliding filament mechanism of muscle contraction. (see Figure 10.6)

1) Myosin heads hydrolyzes ATP and becomes energized and oriented. Since a myosin head includes an ATP binding site that functions as an ATPase, this step is able to occur. The energy generated from this hydrolysis reaction is stored in the myosin head for later use during the cycle. This energy allows for the formation of the cocked position in which myosin can bind to actin. The products of ATP hydrolysis (ADP and phosphate group) are still bound to myosin head. 2) Myosin head binds to actin which forms a cross bridge. The myosin head then releases the previously hydrolyzed phosphate group. Since a myosin molecule technically has two heads, it is important to note that only one head binds to actin at a time. 3) Myosin head pivots, which pulls the thin filament past the thick filament toward center of the sarcomere (power stroke). The energy required to do the power stoke is derived from the energy stored in the myosin head from the hydrolysis of ATP. Once the power stroke occurs, the ADP is released from the myosin head. 4) As myosin head binds to ATP, the cross bridge detaches from actin. As ATP binds to the ATP binding site on the myosin head, the myosin head detaches from the actin.

Explain the sequence of events involved in fracture repair.

1) Reactive phase. This phase is an early inflammatory phase. Blood vessels crossing the fracture line are broken. As blood leaks from the torn ends of the vessels, a mass of blood (usually clotted) forms around the site of the fracture. This mass of blood, called a fracture hematoma (hē′‐ma‐TŌ‐ma; hemat‐ = blood; ‐oma = tumor), usually forms 6 to 8 hours after the injury. Because the circulation of blood stops at the site where the fracture hematoma forms, nearby bone cells die. Swelling and inflammation occur in response to dead bone cells, producing additional cellular debris. Phagocytes (neutrophils and macrophages) and osteoclasts begin to remove the dead or damaged tissue in and around the fracture hematoma. This stage may last up to several weeks. 2) Reparative phase: Fibrocartilaginous callus formation. The reparative phase is characterized by two events: the formation of a fibrocartilaginous callus, and a bony callus to bridge the gap between the broken ends of the bones. Blood vessels grow into the fracture hematoma and phagocytes begin to clean up dead bone cells. Fibroblasts from the periosteum invade the fracture site and produce collagen fibers. In addition, cells from the periosteum develop into chondroblasts and begin to produce fibrocartilage in this region. These events lead to the development of a fibrocartilaginous (soft) callus (fi‐brō‐kar‐ti‐LAJ‐i‐nus), a mass of repair tissue consisting of collagen fibers and cartilage that bridges the broken ends of the bone. Formation of the fibrocartilaginous callus takes about 3 weeks. 3) Bone remodeling phase. The final phase of fracture repair is bone remodeling of the callus. Dead portions of the original fragments of broken bone are gradually resorbed by osteoclasts. Compact bone replaces spongy bone around the periphery of the fracture. Sometimes, the repair process is so thorough that the fracture line is undetectable, even in a radiograph (x‐ray). However, a thickened area on the surface of the bone remains as evidence of a healed fracture.

Explain how spinal nerves are connected to the spinal cord (Fig. 13.4)

1) Sensory receptors detect a sensory stimulus. 2) Sensory neurons convey this sensory input in the form of nerve impulses along their axons, which extend from sensory receptors into the spinal nerve and then into the posterior root. From the posterior root, axons of sensory neurons may proceed along three possible paths (see steps 3, 4, and 5). 3) Axons of sensory neurons may extend into the white matter of the spinal cord and ascend to the brain as part of a sensory tract. 4) Axons of sensory neurons may enter the posterior gray horn and synapse with interneurons whose axons extend into the white matter of the spinal cord and then ascend to the brain as part of a sensory tract. 5)Axons of sensory neurons may enter the posterior gray horn and synapse with interneurons that in turn synapse with somatic motor neurons that are involved in spinal reflex pathways. Spinal cord reflexes are described in more detail later in this chapter. 6) Motor output from the spinal cord to skeletal muscles involves somatic motor neurons of the anterior gray horn. Many somatic motor neurons are regulated by the brain. Axons from higher brain centers form motor tracts that descend from the brain into the white matter of the spinal cord. There they synapse with somatic motor neurons either directly or indirectly by first synapsing with interneurons that in turn synapse with somatic motor neurons. 7)When activated, somatic motor neurons convey motor output in the form of nerve impulses along their axons, which sequentially pass through the anterior gray horn and anterior root to enter the spinal nerve. From the spinal nerve, axons of somatic motor neurons extend to skeletal muscles of the body. 8) Motor output from the spinal cord to cardiac muscle, smooth muscle, and glands involves autonomic motor neurons of the lateral gray horn. When activated, autonomic motor neurons convey motor output in the form of nerve impulses along their axons, which sequentially pass through the lateral gray horn, anterior gray horn, and anterior root to enter the spinal nerve. 9) From the spinal nerve, axons of autonomic motor neurons from the spinal cord synapse with another group of autonomic motor neurons located in the peripheral nervous system (PNS). The axons of this second group of autonomic motor neurons in turn synapse with cardiac muscle, smooth muscle, and glands. Sensory input is conveyed from sensory receptors to the posterior gray horns of the spinal cord, and motor output is conveyed from the anterior and lateral gray horns of the spinal cord to effectors (muscles and glands).

Explain the major events in the physiology of hearing

1) The auricle directs sound waves into the external auditory canal. 2) When sound waves strike the tympanic membrane, the alternating waves of high and low pressure in the air cause the tympanic membrane to vibrate back and forth. The tympanic membrane vibrates slowly in response to low-frequency (low-pitched) sounds and rapidly in response to high- frequency (high-pitched) sounds. 3)The central area of the tympanic membrane connects to the malleus, which vibrates along with the tympanic membrane. This vibration is transmitted from the malleus to the incus and then to the stapes. 4)As the stapes moves back and forth, its oval-shaped footplate, which is attached via a ligament to the circumference of the oval window, vibrates in the oval window. The vibrations at the oval window are about 20 times more vigorous than those of the tympanic membrane because the auditory ossicles efficiently transmit small vibrations spread over a large surface area (the tympanic membrane) into larger vibrations at a smaller surface (the oval window). 5)The movement of the stapes at the oval window sets up fluid pressure waves in the perilymph of the cochlea. As the oval window bulges inward, it pushes on the perilymph of the scala vestibuli. 6)Pressure waves are transmitted from the scala vestibuli to the scala tympani and eventually to the round window, causing it to bulge outward into the middle ear. (See 9 in the figure.) 7)As the pressure waves deform the walls of the scalea vestibuli and scala tympani, they also push the vestibular membrane back and forth, creating pressure waves in the endolymph inside the cochlear duct. 8)The pressure waves in the endolymph cause the basilar membrane to vibrate, which moves the hair cells of the spiral organ against the tectorial membrane. This leads to bending of the stereocilia and ultimately to the generation of nerve impulses in first-order neurons in cochlear nerve fibers.

Describe the components of a feedback system

1. A receptor is a body structure that monitors changes in a controlled condition and sends input to a control center. This pathway is called an afferent pathway (AF-er-ent; af- = toward; -ferrent = carried), since the information flows toward the control center. Typically, the input is in the form of nerve impulses or chemical signals. For example, certain nerve endings in the skin sense temperature and can detect changes, such as a dramatic drop in temperature. 2.A control center in the body, for example, the brain, sets the narrow or set point within which a controlled condition should be maintained, evaluates the input it receives from receptors, and generates output commands when they are needed. Output from the control center typically occurs as nerve impulses, or hormones or other chemical signals. This pathway is called an efferent pathway (EF-er-ent; ef- = away from), since the information flows away from the control center. In our skin temperature example, the brain acts as the control center, receiving nerve impulses from the skin receptors and generating nerve impulses as output. 3.An effector is a body structure that receives output from the control center and produces a response or effect that changes the controlled condition. Nearly every organ or tissue in the body can behave as an effector. When your body temperature drops sharply, your brain (control center) sends nerve impulses (output) to your skeletal muscles (effectors). The result is shivering, which generates heat and raises your body temperature.

Describe the three main parts of a cell

1. The plasma membrane forms the cell's flexible outer surface, separating the cell's internal environment (everything inside the cell) from the external environment (everything outside the cell). It is a selective barrier that regulates the flow of materials into and out of a cell. This selectivity helps establish and maintain the appropriate environment for normal cellular activities. The plasma membrane also plays a key role in communication among cells and between cells and their external environment. 2. The cytoplasm consists of all the cellular contents between the plasma membrane and the nucleus. This compartment has two components: cytosol and organelles. Cytosol, the fluid portion of cytoplasm, also called intracellular fluid, contains water, dissolved solutes, and suspended particles. Within the cytosol are several different types of organelles. Each type of organelle has a characteristic shape and specific functions. Examples include the cytoskeleton, ribosomes, endoplasmic reticulum, Golgi complex, lysosomes, peroxisomes, and mitochondria. 3. The nucleus is a large organelle that houses most of a cell's DNA. Within the nucleus, each chromosome, a single molecule of DNA associated with several proteins, contains thousands of hereditary units called genes that control most aspects of cellular structure and function.

Which of the following muscles act to stabilize the scapula, and would also, when contracted, pull the shoulders back (like a soldier at attention)?1. trapezius 2. levator scapulae 3. rhomboid major and minor

3 only

Describe the baroreflex and the relationship between blood pressure and muscle sympathetic nerve activity

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Describe the primary functions of cerebrospinal fluid (CSF)

A clear, colorless liquid composed of primarily of water that protects the brain and spinal cord from chemical and physical injuries. It also carries small amounts of oxygen, glucose, and other needed chemicals from the blood to neurons and neuroglia. The CSF has three basic functions in helping to maintain homeostasis. 1. Mechanical protection. CSF serves as a shock-absorbing medium that protects the delicate tissues of the brain and spinal cord from jolts that would otherwise cause them to hit the bony walls of the cranial cavity and vertebral canal. The fluid also buoys the brain so that it "floats" in the cranial cavity. 2. Chemical protection. CSF provides an optimal chemical environment for accurate neuronal signaling. Even slight changes in the ionic composition of CSF within the brain can seriously disrupt production of action potentials and postsynaptic potentials. 3.Circulation. CSF is a medium for minor exchange of nutrients and waste products between the blood and adjacent nervous tissue.

Writer's cramp can occur in Anatomy and Physiology lecture class. What factor would most likely contribute to the muscles not being able to relax?

A deficit of ATP keeping myosin from detaching

Distinguish between nerve fiber classification groups

A fibers: Are the largest diameter axons (5-20 um) and are myelinated. A fibers have a brief absolute refractory period and conduct nerve impulses at speeds of 12 to 130 m/sec. The axons of sensory neurons that propagate impulses associated with touch, pressure, position of joints, and some thermal and pain sensations are A fibers, as are the axons of motor neurons that conduct impulses to skeletal muscles. B fibers: are axons with diameters of 2-3 μm. Like A fibers, B fibers are myelinated and exhibit saltatory conduction at speeds up to 15 m/sec (34 mi/hr). B fibers have a somewhat longer absolute refractory period than A fibers. B fibers conduct sensory nerve impulses from the viscera to the brain and spinal cord. They also constitute all of the axons of the autonomic motor neurons that extend from the brain and spinal cord to the ANS relay stations called autonomic ganglia. C fibers: are the smallest diameter axons (0.5-1.5 μm) and all are unmyelinated. Nerve impulse propagation along a C fiber ranges from 0.5 to 2 m/sec (1-4 mi/hr). C fibers exhibit the longest absolute refractory periods. These unmyelinated axons conduct some sensory impulses for pain, touch, pressure, heat, and cold from the skin, and pain impulses from the viscera. Autonomic motor fibers that extend from autonomic ganglia to stimulate the heart, smooth muscle, and glands are C fibers. Examples of motor functions of B and C fibers are constricting and dilating the pupils, increasing and decreasing the heart rate, and contracting and relaxing the urinary bladder.

Describe how the severity of the burn is determined

A first-degree burn involves only the epidermis. It is characterized by mild pain and erythema (redness) but no blisters. Skin functions remain intact. Immediate flushing with cold water may lessen the pain and damage caused by a first-degree burn. Generally, healing of a first-degree burn will occur in 3 to 6 days and may be accompanied by flaking or peeling. One example of a first-degree burn is mild sunburn. A second-degree burn destroys the epidermis and part of the dermis. Some skin functions are lost. In a second-degree burn, redness, blister formation, edema, and pain result. In a blister the epidermis separates from the dermis due to the accumulation of tissue fluid between them. Associated structures, such as hair follicles, sebaceous glands, and sweat glands, usually are not injured. If there is no infection, second-degree burns heal without skin grafting in about 3 to 4 weeks, but scarring may result. First and second-degree burns are collectively referred to as partial-thickness burns. A third-degree burn or full-thickness burn destroys the epidermis, dermis, and subcutaneous layer. Most skin functions are lost. Such burns vary in appearance from marble-white to mahogany colored to charred, dry wounds. There is marked edema, and the burned region is numb because sensory nerve endings have been destroyed. Regeneration occurs slowly, and much granulation tissue forms before being covered by epithelium. Skin grafting may be required to promote healing and to minimize scarring. 1. Count 9% if both the anterior and posterior surfaces of the head and neck are affected. 2. Count 9% for both the anterior and posterior surfaces of each upper limb (total of 18% for both upper limbs). 3. Count four times nine, or 36%, for both the anterior and posterior surfaces of the trunk, including the buttocks. 4. Count 9% for the anterior and 9% for the posterior surfaces of each lower limb as far up as the buttocks (total of 36% for both lower limbs). 5. Count 1% for the perineum.

Describe how a graded potential is generated

A graded potential is a small deviation from the resting membrane potential that makes the membrane either more polarized (inside more negative) or less polarized (inside less negative). When the response makes the membrane more polarized, it is termed a hyper-polarizing graded potential. When the response makes the membrane less polarized, it is termed a depolarizing graded potential.

Compare and contrast receptor agonists and antagonists

A large variety of drugs and natural products can selectively activate or block specific cholinergic or adrenergic receptors. An agonist is a substance that binds to and activates a receptor, in the process mimicking the effect of a natural neurotransmitter or hormone. Phenylephrine, an adrenergic agonist at α1 receptors, is a common ingredient in cold and sinus medications. Because it constricts blood vessels in the nasal mucosa, phenylephrine reduces production of mucus, thus relieving nasal congestion. An antagonist is a substance that binds to and blocks a receptor, thereby preventing a natural neurotransmitter or hormone from exerting its effect. For example, atropine blocks muscarinic ACh receptors, dilates the pupils, reduces glandular secretions, and relaxes smooth muscle in the gastrointestinal tract. As a result, it is used to dilate the pupils during eye examinations, in the treatment of smooth muscle disorders such as iritis and intestinal hypermotility, and as an antidote for chemical warfare agents that inactivate acetylcholinesterase.

Describe a motor unit.

A motor unit consists of a somatic motor neuron plus all of the skeletal muscle fibers it stimulates. Typically, the muscle fibers of a motor unit are dispersed throughout a muscle rather than clustered together.

Define arthroplasty

A surgical procedure that replaces joints with artificial joints. The ends of damaged bones are removed and metal, ceramic, or plastic components are fixed in place. The goals of arthroplasty are to relieve pain and increase ROM.

Explain the phases of a twitch contraction.

A twitch contraction is the brief contraction of all muscle fibers in a motor unit in response to a single AP in its motor neuron. The stages of a twitch contraction are: Latent: A brief delay that occurs between application of the stimulus and the beginning of contraction. it lasts about 2 msec. The muscle action potential sweeps over the sarcolemma and Ca ions are released from the SR. Contraction: The second phase that lasts about 10-100 msec. Ca binds to troponin. Myosin binding sites on actin are exposed and cross bridges form. Peak tension develops in the muscle fiber. Relaxation: The third phase lasts around 10-100 msec. Ca in actively transported back into the SR and myosin binding sites are covered by tropomyosin, myosin heads detach from actin, and tension in the muscle fiber decreases. The actual duration of these periods depend on the type of skeletal muscle fiber. Refractory: A period of lost excitability. It is characteristic of all muscle and nerve cells. The duration varies with the muscle involved. Skeletal muscle has a short refrac period of about 1 msec while cardiac has one of about 250 msec.

Explain the effects of aging on joints.

Aging results in a decreased production of synovial fluid in joints. In addition, the articular cartilage thins with age and ligaments shorten and lose flexibility. These effects can be influenced by genetic factors and by wear and tear, and vary considerably for each person. Degenerative changes in joints can occur at as early as age 20 but usually do not occur until later. By 80, most people have some degeneration of their joints. Homeostatic imbalances also are age related. Nearly everyone over age 7 0 has some osteoarthritic changes. Stretching and aerobic exercises help with maintaining full ROM.

Recall key symptoms + causes of major neurological disorders

Agnosia: Inability to recognize the significance of sensory stimuli such as sounds, sights, smells, tastes, and touch. Aphasia: Loss of ability to understand or express speech caused by brain damage Ataxia: Loss of the ability to coordinate muscular movements. Usually from damage to the cerebellum. Tourette syndrome: symptoms include blinking, eye rolling, grimacing, shoulder shrugging, jerking of the head or other limbs, jumping, twirling, touching objects and other people. Parkinson's disease: brain disorder that leads to shaking, stiffness, and difficulty with walking, balance, and coordination. Usually gradually gets worse.

Define hemispheric lateralization as it relates to brain function

Although the brain is almost symmetrical on its right and left sides, subtle anatomical differences between the two hemispheres exist. For example, in about two-thirds of the population, the planum temporale, a region of the temporal lobe that includes Wernicke's area, is 50% larger on the left side than on the right side. This asymmetry appears in the human fetus at about 30 weeks gestation. Physiological differences also exist; although the two hemispheres share performance of many functions, each hemisphere also specializes in performing certain unique functions. This functional asymmetry is termed hemispheric lateralization. Despite some dramatic differences in functions of the two hemispheres, there is considerable variation from one person to another. Also, lateralization seems less pronounced in females than in males, both for language (left hemisphere) and for visual and spatial skills (right hemisphere). For instance, females are less likely than males to suffer aphasia after damage to the left hemisphere. A possibly related observation is that the anterior commissure is 12% larger and the corpus callosum has a broader posterior portion in females. Recall that both the anterior commissure and the corpus callosum are commissural tracts that provide communication between the two hemispheres.

Explain factors that affect the speed of action potential propagation

Amount of myelination: Action potentials propagate more rapidly along myelinated axons than along unmyelinated axons. Axon diameter: Large diameter axons propagate action potentials faster than smaller ones due to their larger surface areas. Temperature: Axons propagate actions potentials at lower speeds when cooled.

Define anatomy and physiology, and name several branches of these sciences

Anatomy is the science of body structures and the relationships among them. Dissection was one of the first ways it was studied. Branches include: embryology, developmental biology, cell biology, histology, gross anatomy, systemic anatomy, regional anatomy, surface anatomy, imaging anatomy, pathological anatomy Physiology is the science of body functions and how the body parts work. Structures include molecular physiology, neurophysiology, endocrinology, cardiovascular physiology, immunology, respiratory physiology, renal physiology, exercise physiology, and pathophysiology

Describe the structure and function of synovial joints.

Articular (joint) capsule: A sleevelike capsule that surrounds the synovial joint and encloses the synovial cavity, and unites the articulating bones. It is composed of two layers, an outer fibrous membrane and an inner synovial membrane. The fibrous membrane consists of dense irregular CT that attach to the periosteum of the articulating bones. It is quite literally a thickened continuation of the periosteum between the bones. It is flexible and permits movement at a joint while its great tensile strength prevents the bone from dislocating. Ligaments-- fibers arranged as parallel bundles of dense regular CT that are highly adapted for resisting strains, are one of the the most important factors that hold bones close together in a synovial joint. Synovial membrane: The inner layer of the articular cartilage is known as the synovial membrane . It is composed of areolar CT with elastic fibers. They can also contain accumulations of adipose tissue (articular fat pads). articular cartilage: a layer of hyaline cartilage that covers articulating bones with a smooth, slippery surface but does not bind them together. Articular cartilage reduces friction between bones in the joint during movement. Helps absorb shock. synovial (joint) cavity: A unique characteristic of a synovial joint. The synovial cavity is situated between the articulating bones. it allows for considerable movement at a joint and are classified as freely movable (diarthroses). synovial fluid: The synovial membrane secretes synovial fluids, a viscous clear or pale yellow fluid. Consists of hyaluronic acid and interstitial fluid. It forms a thin film layer over the surfaces within the articular capsule. It reduces friction by lubricating the joint, absorbing shocks, and supplying O2 and nutrients to and removing CO2 and metabolic wastes from the chondrocytes within the articular cartilage. It also contains phagocytes that remove microbes and the debris that results from normal wear and tear in the joint.

Describe the three types of tracts found in cerebral white matter

Association: contain axons that conduct nerve impulses between gyri in the same hemisphere Commissural: contain axons that conduct nerve impulses from gyri in one cerebral hemisphere to corresponding gyri in the other cerebral hemisphere. Three important groups of commissural tracts are the corpus callosum, anterior commissure, and posterior commisure. Projection: contain axons that conduct nerve impulses from the cerebrum to lower parts of the CNS or from lower parts of the CNS to the cerebrum. An example is the internal capsule, a thick band of white matter that contains both ascending and descending axons.

Recall major spinal nerves of the brachial plexus

Axillary: The brachial plexus provides almost the entire nerve supply of the shoulders and upper limbs. Five large terminal branches arise from the brachial plexus: the axillary nerve supplies the deltoid and teres minor muscles. Musculocutaneous: Supplies the anterior muscles of the arm. Radial: Supplies the muscles on the posterior aspect of the arm and forearm. Median: Supplies most of the muscles of the anterior forearm and some of the muscles of the hand. Ulnar nerves: Supplies the anteromedial muscles of the forearm and most of the muscles of the hand.

Explain the function of each of the receptor organs for equilibrium

Because the otolithic membrane sits on top of the macula, if you tilt your head forward, the otolithic membrane (along with the otoliths) is pulled by gravity. It slides "downhill" over the hair cells in the direction of the tilt, bending the hair bundles. However, if you are sitting upright in a car that suddenly jerks forward, the otolithic membrane lags behind the head movement due to inertia, pulls on the hair bundles, and makes them bend in the other direction. Bending of the hair bundles in one direction stretches the tip links, which pulls open cation channels, producing depolarizing receptor potentials; bending in the opposite direction closes the cation channels and produces hyperpolarization. As the hair cells depolarize and hyperpolarize, they release neurotransmitter at a faster or slower rate. The hair cells synapse with first-order sensory neurons of the vestibular branch of the vestibulocochlear (VIII) nerve. These neurons fire nerve impulses at a slow or rapid pace depending on the amount of neurotransmitter present. Efferent neurons also synapse with the hair cells and sensory neurons. Evidently, the efferent neurons regulate the sensitivity of the hair cells and sensory neurons.

Outline the equilibrium pathway to the brain

Bending of hair bundles of the hair cells in the semicircular ducts, utricle, or saccule causes the release of a neurotransmitter (probably glutamate), which generates nerve impulses in the sensory neurons that innervate the hair cells. The cell bodies of sensory neurons are located in the vestibular ganglia. Nerve impulses pass along the axons of these neurons, which form the vestibular branch of the vestibulocochlear (VIII) nerve. Most of these axons synapse with sensory neurons in vestibular nuclei, the major integrating centers for equilibrium, in the medulla oblongata and pons. The vestibular nuclei also receive input from the eyes and proprioceptors, especially proprioceptors in the neck and limb muscles that indicate the position of the head and limbs. The remaining axons enter the cerebellum through the inferior cerebellar peduncles. Bidirectional pathways connect the cerebellum and vestibular nuclei.

Describe the blood supply of the brain

Blood flows to the brain mainly via the internal carotid and vertebral arteries. The dural venous sinuses drain into the internal jugular veins to return blood from the head to the heart. The blood brain barrier consists mainly of tight junctions that seal together the endothelial cells of brain blood capillaries and a thick basement membrane that surrounds the capillaries. The BBB allows certain substances in blood to enter brain tissue and prevents passages to others. Lipid soluble substances (o2 and co2), steroid hormones, alcohol, barbiturates, nicotine, and caffeine and water molecules can easily cross the BBB. Lack of blood flow for 4 min = brain damage

Describe the blood and nerve supply of bone

Blood is richly supplied with blood. Blood vessels, which are especially abundant in portions of bone containing red bone marrow, pass into bones from the periosteum. Nerves accompany the blood vessels that supply bones. The periosteum is rich in sensory nerves, some of which carry pain sensations. -Nutrient artery is located near the center of the diaphysis. it passes through a hole in compact bone called the nutrient foramen. It divides into proximal and distal branches that course toward each end of the bone. These branches supply both the inner part of compact bone tissue of the diaphysis and the spongy bone tissue and red bone marrow as far as epiphyseal plate. -Periosteal arteries are small arteries accompanied by nerves, enter the diaphysis through many interostenonic canals and supply the periosteum and outer part of the compact bone. -Metaphyseal arteries enter the metaphyses of a long bone, and together with the nutrient artery, supply the red bone marrow and bone tissue of the metaphyses. -Epiphyseal arteries enter the epiphyses of a long bone and supply the red bone marrow and bone tissue of epiphyses. -Artery/vein: veins that carry blood away from long bones are evident in three places: 1) one or two nutrient veins accompany the nutrient artery and exit through the diaphysis. 2) numerous epiphyseal veins and metaphyseal veins accompany their respective arteries and exit through the epiphyses and metaphyses respectively. 3) many small perosteal veins accompany respective arteries and exit through periosteum.

Functions of the basement membrane

Blood vessels in connective tissue do not penetrate the basement membrane, requiring nutrients to diffuse to the epithelium tissue. Epithelial cells produce the laminin which attaches to the integrins in hemidesmosomes Basement membrane helps support and guide cells in migration during tissue repair.

Discuss the structure and function of bursae and tendon sheaths.

Bursae are sac-like structures that are strategically situated to alleviate friction in some joints, such as the shoulder and the knee joints. They are not strictly apart of synovial joints, but they do resemble joint capsules because their walls consist of an outer fibrous membrane of thin, dense CT lined by a synovial membrane. They are filled with a small amount of fluid and can be located between skin and bones, tendons and bones, muscles and bones, or ligaments and bones. They cushion the movement of these body parts against one another. Tendon sheaths also reduce friction at joints. They are tubelike bursae that wrap around certain tendons that experience a considerable amount of friction as they pass through tunnels formed by CT and bone. The inner later of a tendon sheath is attached to the surface of a tendon. The outer layer, known as the parietal layer is attached to bone. Between the two layers is a cavity that contains a film of synovial fluid. A tendon sheath protects all sides of a tendon from friction as the tendon slides back and forth. They are found where tendons pass through synovial cavities, such as the tendon of the biceps brachii muscle at the shoulder joint. They are also found at the wrist and ankle and in the fingers and toes.

Recall the consequences if a transection of the spinal cord occurs

C1-C3: death by asphyxiation: no function maintained from the neck down; ventilator needed for breathing; electric wheelchair with breath, head, or shoulder-controlled device required. C4-C5: quadriplegia: diaphragm, which allows breathing C6-T10: paraplegia: paralysis of both lower limbs C6-C7: some arm and chest muscles, which allows feeding, some dressing, and manual wheelchair required (see Figure B) T1-T3: intact arm function T4-T9: control of trunk above the umbilicus T10-L1: most thigh muscles, which allows walking with long leg braces (see Figure C)

Describe the organization of the nervous system

CNS: brain + spinal cord. The brain contains about 85 billion neurons. The spinal cord is connected to the brain via the foramen magnum of the occipital bone and is encircled by the bones of the vertebral column. The spinal cord contains about 100 million neurons. The CNS processes many different kinds of incoming sensory information. It is also the source of thoughts, emotions, and memories. PNS: Consists of all nervous tissue outside of the CNS. Compartments of the PNS include nerves and sensory receptors. -Cranial nerves: 12 pairs of cranial nerves emerge from the brain -Spinal nerve: 31 pairs of nerves emerge from the spinal cord Enteric plexuses: The enteric nervous system is an extensive network of over 100 millions neurons confined to the wall of the GI tract. The ENS helps regulate the activity of the smooth muscle and glands of the GI tract. It can function independently, it communicates with and is regulated by the other branches of the ANS. Sensory receptors: Detect internal stimuli, such as an increase in blood pressure, or external stimuli. This sensory information is then carried into the brain and spinal cord through cranial and spinal nerves. Somatic nervous system conveys output from the CNS to skeletal muscles only. Because its motor responses can be consciously controlled, the action of this part of the PNS is voluntary Autonomic system: Conveys output from the CNS to smooth muscle, cardiac muscle, and glands. Because its motor responses are not normally under conscious control, the action of the ANS is involuntary. Sympathetic: Neurons of the nervous system increase HR, helps support exercise or emergency actions/fight or flight reactions. Parasympathetic: Rest or digest functions. Slows HR. Enteric: Extensive network of over 100 million neurons confined to the wall of the GI tract. Helps regulate the activity of the smooth muscle and glands of the GI tract. Although the ENS can function independently, it communicates with and is regulated by the other branches of the ANS.

Describe the functions of major biomolecules

Carbohydrates: include sugars, glycogen, starches, and cellulose. Even though they are a large and diverse group of organic compounds and have several functions, carbohydrates represent only 2-3% of your total body mass. In humans and animals, carbohydrates function mainly as a source of chemical energy for generating ATP needed to drive metabolic reactions. Only a few carbohydrates are used for building structural units. One example is deoxyribose, a type of sugar that is a building block of deoxyribonucleic acid (DNA), the molecule that carries inherited genetic information. Lipids: A second important group of organic compounds is lipids (lip‐ = fat). Lipids make up 18-25% of body mass in lean adults. Like carbohydrates, lipids contain carbon, hydrogen, and oxygen. Unlike carbohydrates, they do not have a 2:1 ratio of hydrogen to oxygen. The proportion of electronegative oxygen atoms in lipids is usually smaller than in carbohydrates, so there are fewer polar covalent bonds. As a result, most lipids are insoluble in polar solvents such as water; they are hydrophobic. Because they are hydrophobic, only the smallest lipids (some fatty acids) can dissolve in watery blood plasma. To become more soluble in blood plasma, other lipid molecules join with hydrophilic protein molecules. The resulting lipid-protein complexes are termed lipoproteins. Lipoproteins are soluble because the proteins are on the outside and the lipids are on the inside. Proteins: Proteins are large molecules that contain carbon, hydrogen, oxygen, and nitrogen. Some proteins also contain sulfur. A normal, lean adult body is 12-18% protein. Much more complex in structure than carbohydrates or lipids, proteins have many roles in the body and are largely responsible for the structure of body tissues. Enzymes are proteins that speed up most biochemical reactions. Other proteins work as "motors" to drive muscle contraction. Antibodies are proteins that defend against invading microbes. Some hormones that regulate homeostasis also are proteins. Nucleic acids: Nucleic acids, so named because they were first discovered in the nuclei of cells, are huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus. Nucleic acids are of two varieties. The first, deoxyribonucleic acid (DNA), forms the inherited genetic material inside each human cell. In humans, each gene (JĒN) is a segment of a DNA molecule. Our genes determine the traits we inherit, and by controlling protein synthesis they regulate most of the activities that take place in body cells throughout our lives. When a cell divides, its hereditary information passes on to the next generation of cells. Ribonucleic acid (RNA), the second type of nucleic acid, relays instructions from the genes to guide each cell's synthesis of proteins from amino acids.

Recognize the major autonomic plexuses

Cardiac: supplies the heart Pulmonary: which supplies the bronchial tree Celiac (solar): largest autonomic plexus and surrounds the celiac trunk. Contains large celiac ganglia, two aortic renal ganglia, and a dense work of autonomic axons and is distributed to many places in the body. Superior: contains the superior mesenteric ganglion and supplies the small and large intestines. Inferior Mesenteric: contains the inferior mesenteric ganglion, which innervates the large intestine.

What are the regions of the vertebral column?

Cervical (7), thoracic (12), lumbar (5), sacrum (1), coccyx (1)

Describe the structures and functions of the brainstem

The brainstem is the part of the brain between the spinal cord and the diencephalon. It consists of three structures: 1) medulla oblongata, 2) pons, and 3) the midbrain. Medulla Oblongata: Continuous with the superior part of the spinal cord; it forms the inferior part of the brain stem. The medulla begins at the foramen magnum and extends to the inferior border of the pons, a distance of about 3 cm. Contains both nuclei and tracts. Responsible for regulating basic functions of the autonomic nervous system--respiration, cardiac function, vasodilation, and reflexes like vomiting, coughing, sneezing, and swallowing. Pons: Lies directly superior to the medulla and anterior to the cerebellum. About 2.5 cm long. Consists of both nuclei and tracts. It is the bridge that connects parts on the brain with one another. These connections are provided by bundles of axons. Some axons of the pons connect the right and left sides of the cerebellum. Others are part of ascending sensory tracts and descending motor tracts. Sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture. Midbrain: Extends from the pons to the diencephalon and is about 2.5 cm long. Contains both nuclei and tracts. Associated with vision, hearing, motor control, sleep and wake cycles, arousal, and temperature regulation. **** During development, the mesencephalon gives rise to the midbrain and aqueduct of midbrain, the diencephalon gives rise to the thalamus, hypothalamus, and third ventricle and the myelencephalon forms the medulla oblongata.

Regeneration

The capability to replicate or repair

Recall the structure and function of the cytoplasm, cytosol, and common organelles

Cilia: small hair like projections on the outside of eukaryotic cells. Primarily responsible for locomotion; either of the cell itself or of fluids on the cell surface. Flagella: locomotion and a sensory organelle that can be sensitive to chemicals and temps outside of the cell. Ribosomes: Composed of two subunits containing ribosomal RNA and proteins; may be free in cytosol or attached to rough ER. Function: protein synthesis. Endoplasmic reticulum: Membranous network of flattened sacs or tubules. Rough ER is covered by ribosomes and is attached to the nuclear envelope; smooth ER lacks ribosomes. Function includes Rough ER: synthesizes glycoproteins and phospholipids that are transferred to cellular organelles, inserted into plasma membrane, or secreted during exocytosis; smooth ER: synthesizes fatty acids and steroids, inactivates or detoxifies drugs, removes phosphate group from glucose-6-phosphate, and stores and releases calcium ions in muscle cells. Golgi complex: Consists of 3-20 flattened membranous sacs called cisternae; structurally and functionally divided into entry (cis) face, medial cisternae, and exit (trans) face. Function include: Entry (cis) face accepts proteins from rough ER; medial cisternae form glycoproteins, glycolipids, and lipoproteins; exit (trans) face modifies molecules further, then sorts and packages them for transport to their destinations. Mitochondria: Consists of an external and an internal mitochondrial membrane, cristae, and matrix; new mitochondria form from preexisting ones. Functions include: Site of aerobic cellular respiration reactions that produce most of a cell's ATP. Plays an important early role in apoptosis.

Recall major spinal nerves of the cervical plexus

The cervical plexus supplies the skin and muscles of the head, neck, and superior part of the shoulders and chest. The phrenic nerves arise from the C3 to C5 cervical plexuses and supply motor fibers to the diaphragm. Branches of the cervical plexus also run parallel to two cranial nerves, the accessory (XI) nerve and hypoglossal (XII) nerve. Origin C3-C5, diaphragm

Compare the structural and functional differences between compact and spongy bone tissue.

Compact bone tissue contains few spaces and is the strongest form of bone tissue. Found beneath the periosteum of all bones and makes up the bulk of the diaphysis of long bones. Provides protection and supports and resists stress from weight and movement. -Spongy bone tissue (trabecular or cancellous bone tissue) does NOT contain osteons. Spongy bone is always located in the interior of a bone, protected by a covering of compact bone. Consists of lamallae that are arranged in an irregular pattern of thin columns called trabeculae. Between the trabeculae are red bone marrow or yellow hone marrow depending on the bone. Each trabecula consists of concentric lamellae, osteocytes that lie in lacunae, and canliculi that radiate outward from the lacunae. -Osteon: repeating structural units in compact bone tissue. Aligned in the same direction and are parallel to the length of the diaphysis. Each osteon has concentric lamallae arranged around a canal. Concentric lamallae are circular plates of mineralized ECM surrounding a small network of blood vessels and nerves located in the central canal. Between concentric lamallae are small spaces called lacunae which contain osteocytes. Radiating from lacunae are canaliculi.

Craniodiaphyseal dysplasia is a bone disorder that causes calcium to accumulate in the skull. These deposits of calcium decrease the foramina size in the skull. What would be an effect of smaller foramina?

Compression on cranial nerves may occur, inadequate blood flow to structures in the skull, intracranial hypertension (high BP)

Describe the functions of skeletal muscle proteins.

Contractile Proteins: Proteins that help generate force during muscle contractions. Myosin- Makes up a thick filament. A molecule consists of a tail and two myosin heads which bind to myosin binding sites on actin molecules of thin filament during muscle contraction. Actin- Main component of thin filament; each actin molecule has a myosin-binding site where myosin head of thick filaments binds during muscle contraction. Regulatory Proteins: Proteins that help switch muscle contraction process on and off. Tropomyosin- A component of thin filament. When skeletal muscle fiber is relaxed, tropomyosin covers myosin-binding sites of actin molecules which thereby prevent myosin from binding to actin. Troponin- A component of thin filament. When Ca ions bind to troponin, it changes shape. This conformational change moves tropomyosin away from myosin-binding sites on actin molecules, and muscle contraction begins as myosin binds to actin. Structural: Proteins that keep thick and thin filaments of myofibrils in proper alignment. They give myofibrils elasticity and extensibility and lick myofibrils to sarcolemma and ECM. Titin- Connects Z disc to M line of sarcomere, thereby helping to stabilize thick filament position. It can stretch and then spring back unharmed, and thus accounts for much of the elasticity and extensibility of myofibrils.

Describe how the brain is protected

Cranium, cranial meninges: The spinal meninges surround the spinal cord and are continuous with the cranial meninges, which encircle the brain. Dura mater (periosteal + meningeal): The most superficial of the three spinal meninges is a thick strong layer composed of dense irregular connective tissue. The dura mater forms a sac from the level of the foramen magnum in the occipital bone, where it is continuous with the meningeal dura mater of teh brain, to the second sacral vertebra. The dura mater is also continuous with the epineurum, the outer covering of spinal and cranial nerves. Arachnoid mater: This layer, the middle of the meningeal membranes, is a thin, avascular covering comprised of cells and thin, loosely arranged collagen and elastic fibers. It is called the arachnoid mater because of its spider's web arrangement of delicate collagen fibers and some elastic fibers. It is deep to the dura mater and is continuous through the foramen magnum with the arachnoid mater of the brain. Between the dura mater and the arachnoid mater is a thin subdural space, which contains interstitial fluid. Pia mater: This innermost meninx is a thin transparent connective tissue layer that adheres to the surface of the spinal cord and brain. It consists of thin squamous to cuboidal cells within interlacing bundles of collagen fibers and some fine elastic fibers. Within the pia mater are many blood vessels that supply oxygen and nutrients to the spinal cord. Triangular-shaped membranous extensions of the pia mater suspend the spinal cord in the middle of its dural sheath. These extensions, called denticulate ligaments (den-TIK-ū-lāt = small tooth), are thickenings of the pia mater. They project laterally and fuse with the arachnoid mater and inner surface of the dura mater between the anterior and posterior nerve roots of spinal nerves on either side Falx cerebri: Separates the two hemispheres of the cerebrum along the sagittal section or plane. Falx cerebelli: Separates the two hemispheres of the cerebellum Tentorium cerebelli: Separates the cerebrum from the cerebellum

Compare three major methods of ATP production in muscle fibers. Describe when each method is used briefly how ATP is generated.

Creatine phosphate: When muscle fibers relax, they produce more ATP than they need for resting metabolism. Most of this excess ATP is used to synthesize creatine phosphate (an energy rich molecule that is found in muscle fibers). Creatine kinase catalyzes the transfer of one of the high energy phosphate groups from ATP to creatine, forming creatine phosphate and ADP. Creatine is a small amino-acid like structure that is synthesized in the liver, kidneys, and pancreas and then transported to muscle fibers. When contraction begins and the ADP levels start to rise, CK catalyzes the transfer of a high energy phosphate group from creatine phosphate back to ADP. This direct phosphorylation reaction quickly generates new ATP molecules. Since this occurs very rapidly, creatine phosphate is the first source of energy when muscle contraction begins. Other energy generating mechanisms in a muscle fiber take a relatively longer period of time to produce ATP compared to creatine phosphate. Between ATP and CP, there is enough energy storage for muscles to contract maximally for about 15 seconds. Anaerobic glycolysis: When muscle activity continues and the supply of creatine phosphate within the muscle fiber is depleted, glucose is catabolized to generate ATP. Glucose passes easily from blood into contracting muscle fibers via facilitated diffusion. It is also produced by a breakdown of glycogen in muscles. A series of reactions breaks down 1 glucose molecule into 2 molecules of pyruvic acid. This occurs in the cytosol and produces a net gain of 2 molecules of ATP. It does not require oxygen -- it can occur in aerobic and anaerobic settings. Ordinarily, the pyruvic acid will enter the mitochondria and then undergo oxygen-requiring reactions. This produces a large amount of ATP. During anaerobic conditions, pyruvic acid is converted to lactic acid. Each molecule of glucose forms 2 molecules of LA and 2 molecules of ATP. Lactic acid diffuses into the blood, where liver can convert to glucose. This process produces fewer ATP but it is faster. Provides enough energy for about 2 minutes of max muscle activity. Aerobic respiration: If oxygen is present, the pyruvic acid enters the mitochondria and goes through the krebs cycle and the ETC that produces ATP, CO2, H2O, and heat. Each molecule of glucose catabolized under aerobic conditions yields about 30-32 molecules of ATP. Aerobic respiration supplies enough ATP for muscles during periods of rest or light to moderate exercise provided sufficient oxygen and nutrients are available. In activities that last from several mins to an hour +, this type of respiration provides nearly all of the needed ATP.

Saltatory conduction

Current passes through a myelinated axon only at the nodes of Ranvier Current occurs at faster rates Voltage-gated channels are concentrated in unmyelinated regions

Define basal nuclei

Deep within each cerebral hemisphere are three nuclei (masses of gray matter) that are collectively termed the basal nuclei. The basal nuclei receive input from the cerebral cortex and provide output to motor parts of the cortex via the medial and ventral group nuclei of the thalamus. In addition, the basal nuclei have extensive connections with one another. A major function of the basal nuclei is to help regulate initiation and termination of movements. Activity of neurons in the putamen precedes or anticipates body movements; activity of neurons in the caudate nucleus occurs prior to eye movements. The globus pallidus helps regulate the muscle tone required for specific body movements. The basal nuclei also control subconscious contractions of skeletal muscles. In addition to influencing motor functions, the basal nuclei have other roles. They help initiate and terminate some cognitive processes, attention, memory, and planning, and may act with the limbic system to regulate emotional behaviors. Disorders such as Parkinson's disease, obsessive-compulsive disorder, schizophrenia, and chronic anxiety are thought to involve dysfunction of circuits between the basal nuclei and the limbic system

Define muscle fatigue and describe the factors that contribute to it.

Defined as the inability of a muscle to maintain force of contraction after prolonged activity. It mainly results from changes within muscle fibers. It is unclear the precise mechanisms that cause muscle fatigue -- however some factors that are though to contribute include inadequate release of Ca ions from the SR which results in a decline of Ca concentration in the sarcoplasm. Depletion of creatine phosphate also is associated with fatigue. Insufficient oxygen, depletion of glycogen and other nutrients, build up lactic acid and ADP, and failure of APs in the motor neuron to release enough Ach are also all factors contributing to muscle fatigue.

Recall structures of neurons

Dendrites: The receiving or input portions of a neuron. The plasma membranes of dendrites contain numerous receptor sites for binding chemical messengers from other cells. Dendrites are usually short, tapering, and highly branched. In many neurons the dendrites form a tree shaped array of processes extending from the cell body. Their cytoplasm contains nissl bodies, mitochondria, and other organelles. Cell body: Also known as the perikaryon or soma, contains a nucleus surrounded by cytoplasm that includes typical cellular organelles such as lysosomes, mitochondria, and golgi complex. Neuronal cell bodies also contain free ribosomes and prominent clusters of rough ER termed nissl bodies. Nissl bodies: The ribosomes are the sites of protein synthesis. Newly synthesized proteins produced by nissl bodies are used to replace cellular components, as material growth of neurons, and to regenerate damaged axons in the PNS. Axon: The single axon of a neuron propagates nerve impulses toward another neuron, a muscle fiber, or a gland cell. An axon is a long, thin, cylindrical projection that often joins to the cell body at a cone-shaped elevation called the axon hillock. In most neurons, nerve impulses arise at the junction of the azon hillock and the initial segment, an area called the trigger zone, from which they travel along the axon to their destination. Myelin sheath: A multi-layered lipid and protein covering around some axons that insulates them and increases the speed of nerve impulse conduction. nodes of ranvier: Gaps in the myelin sheath that appear at intervals along the axon. Each schwann cell wraps one axon segment between two nodes. Axon terminal: The axon and its collaterals end by dividing into many fine processes called axon terminals. Synaptic end bulb: The tip of some axon terminals swell into bulb-shaped structures called synaptic end bulbs. Contains tiny membrane enclosed sacs called synaptic vesicles that store a chemical called a neurotransmitter.

Describe the phases of an action potential and how each is generated (Fig. 12.18) DRAW THIS

Depolarizing: When a depolarizing graded potential or some other stimulus causes the membrane of the axon to depolarize to threshold, voltage-gated Na+ channels open rapidly. Both the electrical and the chemical gradients favor inward movement of Na+, and the resulting inrush of Na+ causes the depolarizing phase of the action potential. The inflow of Na+ changes the membrane potential from −55 mV to +30 mV. At the peak of the action potential, the inside of the membrane is 30 mV more positive than the outside. Each voltage-gated Na+ channel has two separate gates, an activation gate and an inactivation gate. In the resting state of a voltage-gated Na+ channel, the inactivation gate is open, but the activation gate is closed. As a result, Na+ cannot move into the cell through these channels. At threshold, voltage-gated Na+ channels are activated. In the activated state of a voltage-gated Na+ channel, both the activation and inactivation gates in the channel are open and Na+ inflow begins. As more channels open, Na+ inflow increases, the membrane depolarizes further, and more Na+ channels open. This is an example of a positive feedback mechanism. During the few ten-thousandths of a second that the voltage-gated Na+ channel is open, about 20,000 Na+ flow across the membrane and change the membrane potential considerably. However, the concentration of Na+ hardly changes because of the millions of Na+ present in the extracellular fluid. The sodium-potassium pumps easily bail out the 20,000 or so Na+ that enter the cell during a single action potential and maintain the low concentration of Na+ inside the cell. Repolarizaing: Shortly after the activation gates of the voltage-gated Na+ channels open, the inactivation gates close. Now the voltage-gated Na+ channel is in an inactivated state. In addition to opening voltage-gated Na+ channels, a threshold-level depolarization also opens voltage-gated K+ channels. Because the voltage-gated K+ channels open more slowly, their opening occurs at about the same time the voltage-gated Na+ channels are closing. The slower opening of voltage-gated K+ channels and the closing of previously open voltage-gated Na+ channels produce the repolarizing phase of the action potential. As the Na+ channels are inactivated, Na+ inflow slows. At the same time, the K+ channels are opening, accelerating K+ outflow. Slowing of Na+ inflow and acceleration of K+ outflow cause the membrane potential to change from +30 mV to −70 mV. Repolarization also allows inactivated Na+ channels to revert to the resting state. After-hyperpolarizaing: While the voltage-gated K+ channels are open, outflow of K+ may be large enough to cause an after-hyperpolarizing phase of the action potential. During this phase, the voltage-gated K+ channels remain open and the membrane potential becomes even more negative (about −90 mV). As the voltage-gated K+ channels close, the membrane potential returns to the resting level of −70 mV. Unlike voltage-gated Na+ channels, most voltage-gated K+ channels do not exhibit an inactivated state. Instead, they alternate between closed (resting) and open (activated) states. Refractory period: The period of time after an action potential begins during which an excitable cell cannot generate another action potential in response to a normal threshold stimulus is called the refractory period. During the absolute refractory period, even a very strong stimulus cannot initiate a second action potential. This period coincides with the period of Na+ channel activation and inactivation. Inactivated Na+ channels cannot reopen; they first must return to the resting state. In contrast to action potentials, graded potentials do not exhibit a refractory period. Large-diameter axons have a larger surface area and have a brief absolute refractory period of about 0.4 msec. Because a second nerve impulse can arise very quickly, up to 1000 impulses per second are possible. Small-diameter axons have absolute refractory periods as long as 4 msec, enabling them to transmit a maximum of 250 impulses per second. Under normal body conditions, the maximum frequency of nerve impulses in different axons ranges between 10 and 1000 per second. The relative refractory period is the period of time during which a second action potential can be initiated, but only by a larger-than-normal stimulus. It coincides with the period when the voltage-gated K+ channels are still open after inactivated Na+ channels have returned to their resting state

Name the bones and surface markings of the appendicular skeleton. (figures from slides only)

Describe the relationship between the bones + surface markings

Describe anatomical position

Descriptions of any region or part of the human body assume that it is in a standard position of reference called the anatomical position. In the anatomical position, the subject stands erect facing the observer, with the head level and the eyes facing directly forward. The lower limbs are parallel and the feet are flat on the floor and directed forward, and the upper limbs are at the sides with the palms turned forward

Explain seven features used in naming skeletal muscles

Direction: orientation of muscle fascicles relative to the body's midline Size: Relative size of the muscle Shape: Relative shape of the muscle Action: Principal action of the muscle Number of origins: Number of tendons of origin Location: Structure near which a muscle is found Origin + insertion: Sites where muscle originates and inserts

Describe the major sympathetic responses

During physical or emotional stress, the sympathetic division dominates the parasympathetic division. High sympathetic tone favors body functions that can support vigorous physical activity and rapid production of ATP. At the same time, the sympathetic division reduces body functions that favor the storage of energy. Besides physical exertion, various emotions—such as fear, embarrassment, or rage—stimulate the sympathetic division. Visualizing body changes that occur during "E situations" such as exercise, emergency, excitement, and embarrassment will help you remember most of the sympathetic responses. Activation of the sympathetic division and release of hormones by the adrenal medullae set in motion a series of physiological responses collectively called the fight-or-flight response, which includes the following effects: -The pupils of the eyes dilate. -Heart rate, force of heart contraction, and blood pressure increase. -The airways dilate, allowing faster movement of air into and out of the lungs. -The blood vessels that supply the kidneys and gastrointestinal tract constrict, which decreases blood flow through these tissues. -The result is a slowing of urine formation and digestive activities, which are not essential during exercise. -Blood vessels that supply organs involved in exercise or fighting off danger—skeletal muscles, cardiac muscle, liver, and adipose tissue—dilate, allowing greater blood flow through these tissues. -Liver cells perform glycogenolysis (breakdown of glycogen to glucose), and adipose tissue cells perform lipolysis (breakdown of triglycerides to fatty acids and glycerol). -Release of glucose by the liver increases blood glucose level. -Processes that are not essential for meeting the stressful situation are inhibited. For example, muscular movements of the gastrointestinal tract and digestive secretions slow down or even stop. The effects of sympathetic stimulation are longer lasting and more widespread than the effects of parasympathetic stimulation for three reasons: (1) Sympathetic postganglionic axons diverge more extensively; as a result, many tissues are activated simultaneously. (2) Acetylcholinesterase quickly inactivates acetylcholine, but norepinephrine lingers in the synaptic cleft for a longer period. (3) Epinephrine and norepinephrine secreted into the blood from the adrenal medullae intensify and prolong the responses caused by NE liberated from sympathetic postganglionic axons. These blood-borne hormones circulate throughout the body, affecting all tissues that have alpha and beta receptors. In time, blood-borne NE and epinephrine are destroyed by enzymes in the liver.******************* Stimulates sweat glands, synapses with smooth muscle in blood vessel walls, short preganglionic neurons, and releases hormones

Compare the anatomy of the sympathetic and parasympathetic divisions of the autonomic nervous system

Each division of the ANS has two motor neurons: pre and post ganglionic neurons. In the sympathetic division, the pre ganglionic neuron have their cell bodies in the lateral horns of the gray matter in the 12 thoracic segments and the first two lumbar segments of the spinal cord. For this reason, the sympathetic division is also called the thoracolumbar division. Sympathetic ganglia are the sites of the synapses between sympathetic pre and post ganglionic neurons. There are two major types: sympathetic trunk ganglia and pre-vertebral ganglia. In the parasympathetic division, the pre ganglionic neurons are located in the nuclei of four cranial nerves in the brainstem and in the lateral gray matter of the second through fourth sacral segments of the spinal cord. Hence, it is also known as the craniosacral division. Parasympathetic ganglia synapse with post ganglionic neurons in terminal ganglia. Most of these ganglia are located close to or actually within the wall of a visceral organ. Both parasympathetic and sympathetic divisions neurons form tangled networks called autonomic plexuses.

Describe the structure of taste buds and papillae

Each taste bud is an oval body consisting of three kinds of epithelial cells: supporting cells, gustatory receptor cells, and basal cells Taste buds are found in elevations on the tongue called papillae which increase the surface area and provide a rough texture to the upper surface of the tongue Three types of papillae contain taste buds: 1) Vallate papillae 2)Fungiform papillae 3) Foilate papillae

Describe the components, connective tissue coverings, and branching of a spinal nerve

Epineurium: The outermost covering over the entire nerve Perineurium: Groups of axons with their endoneurim are held together in bundles called fascicles, each of which is wrapped in perineurium, the middle layer. Endoneurium: Individual axons within a nerve, whether myelinated or unmyelinated, are wrapped in endoneurium which is the innermost layer. The perineurium is a thicker layer of connective tissue. It consists of up to 15 layers of fibroblasts within a network of collagen fibers. Surrounds the axons. Posterior (dorsal) + anterior (ventral) ramus: The spinal nerve splits into a posterior and an anterior ramus each receiving fibers from both nerve roots. Posterior: nerves travel to deep muscles and skin on posterior trunk Anterior: nerves travel to skin on anterior and lateral trunk; muscles of upper and lower limbs

Recall the four basic types of tissues that make up the human body and their general characteristics

Epithelial: covers body surfaces and lines hollow organs, body cavities, and ducts; it also forms glands. This tissue allows the body to interact with both its internal and external environments. Connective: protects and supports the body and its organs. Various types of connective tissues bind organs together, store energy reserves as fat, and help provide the body with immunity to disease‐causing organisms. Muscular: is composed of cells specialized for contraction and generation of force. In the process, muscular tissue generates heat that warms the body. Nervous: detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve action potentials (nerve impulses) that activate muscular contractions and glandular secretions.

Describe four special properties of muscular tissue.

Excitability: Happens in both muscle and nerve cells. It is the ability to respond to certain stimuli by producing electric signals called action potentials. Two main types of stimuli trigger action potential in muscle cells: autorhythmic electrical signals and chemical stimuli. Contractility: The ability of the muscular tissue to contract forcefully when stimulated by an action potential. When a skeletal muscle contracts, it generates tension while pulling on its attachment points. If the tension is great enough to overcome the resistance of the object to be moved, the muscle will shorten and the movement occurs. Extensibility: The ability of muscular tissue to stretch (to an extent) without be damaged. The CT within the muscle limits the range of extensibility and keeps it within the range of the muscle cells. Smooth muscle is subject to the greatest amount of stretching, with cardiac muscle cells also stretching each time the heart fills with blood. Elasticity: The ability of muscular tissue to return to original length and shape after contraction or extension.

Describe excitatory + inhibitory postsynaptic potentials (EPSP + IPSP)

Excitatory postsynaptic potential: A depolarizing postsynaptic potential. Although a single EPSP normally does not initiate a nerve impulse, the postsynaptic cell does become more excitable. Because it is partially depolarized, it is more likely to reach threshold when the next EPSP occurs. Inhibitory postsynaptic potential: A neurotransmitter that causes hyper-polarization of the postsynaptic membrane is inhibitory. During hyper-polarization generation of an action potential is more difficult than usual because the membrane potential becomes inside more negative and thus even farther from threshold than in its resting state. *** A postsynaptic neuron responds to acetylcholine neurotransmitter by creating either EPSP or IPSP

Describe the anatomy of the structure in the three main regions of the ear

External (Outer) Ear: Auricle (pinna): Collects sound waves. External auditory canal (external auditory meatus): Directs sound waves to eardrum.Tympanic membrane (eardrum): Sound waves cause it to vibrate, which in turn causes malleus to vibrate. Middle Ear: Auditory ossicles: Transmit and amplify vibrations from tympanic membrane to oval window.Auditory tube (eustachian tube): Equalizes air pressure on both sides of tympanic membrane. Internal (Inner) Ear: Cochlea: Contains a series of fluids, channels, and membranes that transmit vibrations to spiral organ (organ of Corti), the organ of hearing; hair cells in spiral organ produce receptor potentials, which elicit nerve impulses in cochlear branch of vestibulocochlear (VIII) nerve.Vestibular apparatus: Includes semicircular ducts, utricle, and saccule, which generate nerve impulses that propagate along vestibular branch of vestibulocochlear (VIII) nerve.Semicircular ducts: Detect rotational acceleration or deceleration.Utricle: Detects linear acceleration or deceleration that occurs in a horizontal direction and also head tilt.Saccule: Detects linear acceleration or deceleration that occurs in a vertical direction.

Distinguish between the false and true pelves.

False pelvis is upper. True pelvis is lower. The portion of the bony pelvis superior to the pelvic brim is considered to be the false pelvis. It is bordered by the lumbar vertebrae posteriorly, the upper portion of the hip bones laterally, and the abdominal wall anteriorly. The space enclosed by the false pelvis is part of the lower abdomen; contains the superior portion of the bladder and the lower intestines in both gender and the uterus, ovaries, and uterine tubes of the female. The portion of the bony pelvis INFERIOR to the pelvic brim is the true pelvis. It has an inlet, an outlet, and a cavity. It is bounded by the sacrum and coccyx posteriorly, inferior portions of the ilium and ischium laterally, and the pubic bones anteriorly. The true pelvis surrounds the pelvic cavity. The true pelvis contains the rectum and bladder in both genders, the vagina and cervix of the uterus in females, and the prostate in males. The pelvic axis is an imaginary line that curves through the true pelvis from the central point of the plane of the pelvic inlet to the central point of the plane of the pelvic outlet.

Recall the major body cavities, the organs they contain, and their associated linings

The cranial bones form a hollow space of the head called the cranial cavity, which contains the brain. The bones of the vertebral column (backbone) form the vertebral (spinal) canal, which contains the spinal cord. The cranial cavity and vertebral canal are continuous with one another. Three layers of protective tissue, the meninges, and a shock-absorbing fluid surround the brain and spinal cord. The major body cavities of the trunk are the thoracic and abdominopelvic cavities. The thoracic cavity or chest cavity is formed by the ribs, the muscles of the chest, the sternum (breastbone), and the thoracic portion of the vertebral column. Within the thoracic cavity are the pericardial cavity, a fluid-filled space that surrounds the heart, and two fluid-filled spaces called pleural cavities, one around each lung. The central part of the thoracic cavity is an anatomical region called the mediastinum. It is between the lungs, extending from the sternum to the vertebral column and from the first rib to the diaphragm. The mediastinum contains all thoracic organs except the lungs themselves. Among the structures in the mediastinum are the heart, esophagus, trachea, thymus, and several large blood vessels that enter and exit the heart. The diaphragm is a dome-shaped muscle that separates the thoracic cavity from the abdominopelvic cavity. The abdominopelvic cavity extends from the diaphragm to the groin and is encircled by the abdominal muscular wall and the bones and muscles of the pelvis. As the name suggests, the abdominopelvic cavity is divided into two portions, even though no wall separates them. The superior portion, the abdominal cavity, contains the stomach, spleen, liver, gallbladder, small intestine, and most of the large intestine. The inferior portion, the pelvic cavity, contains the urinary bladder, portions of the large intestine, and internal organs of the reproductive system. Organs inside the thoracic and abdominopelvic cavities are called viscera.

Describe the microscopic anatomy of skeletal muscle fibers.

Fascia:A dense sheet or broad band of irregular CT that lines the body wall and limbs and supports and surrounds the muscles with other organs of the body. It allows free movement of muscles, carries nerves, blood vessels, and lymphatic vessels as well as filling spaces between muscles. Wraps around groups of muscles. Tendon: A rope-like structure that attaches a muscle to the periosteum of a bone. Epimysium: The outer layer, encircling the entire muscle. Consists of dense irregular CT. Encircles muscle. Perimysium: A layer of dense, irregular CT but it surrounds groups of 10 to 100 or more muscle fibers which are separated into fascicles. Many fascicles are large enough to be seen with the naked eye. Encircles fascicles. Endomysium: Penetrates the interior of each fascicle and separates individual muscle fibers from one another. The endomysium is mostly reticular fibers. Separates muscle fibers. Myofibril: Little structures on the sarcoplasm -- they are the contractile organelles of skeletal muscle. They are roughly 2 mew meters in diameter and extend the entire length of a muscle fiber. Their prominent striations make the entire skeletal muscle look more striated. Composed of repeating units called sarcomeres. Sarcolemma: The plasma membrane of a muscle cell. Transverse (t) tubules: Tiny invaginations of the sarcolemma. They are filled with interstitial fluid. Muscle action potentials travel along the sarcolemma and through the T tubules, quickly spreading throughout the muscle fiber. This ensures excitability at the same instant regardless of which part of the muscle it is happening in. Sarcoplasm: The cytoplasm of a muscle fiber. Includes a substantial amount of glycogen which can be used for ATP synthesis. Sarcoplasmic reticulum: A fluid filled system of membraneous sacs that encircles each myofibril. In a relaxed muscle fiber, the SR stores calcium ions. The release of calcium from the SR triggers muscle contraction. Sarcomeres: Basic functional units of myofibrils. Z discs separate one sarcomere from the next.

Recall major spinal nerves of the lumbar plexus

Femoral: Largest nerve arising from lumbar plexus; distributed to flexor muscles of hip joint and extensor muscles of knee joint, skin over anterior and medial aspect of thigh and medial side of leg and foot. Obturator nerve: Adductor muscles of hip joint; skin over medial aspect of thigh

Describe the structural classification of joints.

Fibrous: There is no synovial cavity and the bones are held together by dense irregular connective tissue that is rich in collagen fibers. Cartilaginous: There is no synovial cavity, and the bones are held together by cartilage. Synovial: The bones forming the joint have a synovial cavity and are united by dense irregular connective tissue of an articular capsule, and often by accessory ligaments.

Define visible light

The eyes are responsible for the detection of visible light, the part of the electromagnetic spectrum with wavelengths ranging from about 400 to 700 nm. Visible light exhibits colors: The color of visible light depends on its wavelength. For example, light that has a wavelength of 400 nm is violet, and light that has a wavelength of 700 nm is red. An object can absorb certain wavelengths of visible light and reflect others; the object will appear the color of the wavelength that is reflected. For example, a green apple appears green because it reflects mostly green light and absorbs most other wavelengths of visible light. An object appears white because it reflects all wavelengths of visible light. An object appears black because it absorbs all wavelengths of visible light.

Compare the three types of lever systems based on the location of the fulcrum, effort, and load. Be able to provide examples found in the human body. Also note the presence of a mechanical advantage.

First-class: The fulcrum is between the effort and the load in first-class levers. Scissors and seesaws are examples of these type of levers. It can either promote a mechanical advantage or disadvantage depending on if the effort of the load is closer to the fulcrum. If the effort is farther from the fulcrum than the load, a heavy load can be moved, but not very far or fast. There are few first class levers in the body--example includes the lever formed by the head resting on the vertebral column: the contraction of the posterior neck muscles provides the effort, the joint between the atlas and occipital bone forms the fulcrum, and the weight of the anterior portion of the skull is the load. Second-class: The load is between the fulcrum and the effort in these type of levers. They operate like a wheel barrow. They will always produce a mechanical advantage because the load is always closer to the fulcrum than the effort. This sacrifices speed and range of the motion for force; it produces the most force out of the three levers. Example: standing up on your toes. The fulcrum is the ball of the foot, the load is the weight of the body, the effort is the contraction of the muscles of the calf which raises the heel off the ground. Third-class levers: The effort is between the fulcrum and the load in these levers. They operate like a pair of forceps and are the most common levers in the body. They always produce a mechanical disadvantage because the effort is always closer to the fulcrum than the load. In the body, the arrangement favors speed and range of motion over force. Examples: the elbow joint, the biceps brachii, and the bones of the arm and forearm. When flexing the forearm at the elbow the elbow joint is the fulcrum, the contraction of the biceps brachii is the effort and then weight of the hand and forearm is the load.

Describe the general components of a sensory pathway

First-order: are sensory neurons that conduct impulses from somatic sensory receptors into the brainstem or spinal cord. All other neurons in a somatic sensory pathway are interneurons, which are located completely within the central nervous system (CNS). From the face, nasal cavity, oral cavity, teeth, and eyes, somatic sensory impulses propagate along the cranial nerves into the brainstem. From the neck, trunk, limbs, and posterior aspect of the head, somatic sensory impulses propagate along spinal nerves into the spinal cord. ***** They are located in the posterior root ganglion and in the trigeminal nucleus. They are typically unipolar. Their axons do NOT decussate. They fire generator potentials which may summate to action potentials. Second-order: conduct impulses from the brainstem or spinal cord to the thalamus. Axons of second-order neurons decussate (cross over to the opposite side) as they course through the brainstem or spinal cord before ascending to the thalamus. Third-order neurons: conduct impulses from the thalamus to the primary somatosensory area on the same side. As the impulses reach the primary somatosensory area, perception of the sensation occurs. Because the axons of second-order neurons decussate as they pass through the brainstem or spinal cord, somatic sensory information on one side of the body is perceived by the primary somatosensory area on the opposite side of the brain.********First order neurons carry afferent signals from the sensory receptor to the CNS. Third order neurons carry afferent signals from the thalamus to the cerebral cortex. Second order neurons carry sensory information from the CNS to the thalamus.

Define key terms used to describe surface markings on bones.

Fissure: Narrow slit between adjacent parts of bones through which blood vessels or nerves pass. Foramen: Opening through which blood vessels, nerves, or ligaments pass. Fossa: Shallow depression Sulcus: Furrow along bone surface that accommodates blood vessel, nerve, or tendon. Meatus: Tubelike opening. Condyle: Large, round protuberance with a smooth articular surface at end of bone. Facet: Smooth, flat, slightly concave or convex articular surface. Head: Usually rounded articular projection supported on neck (constricted portion) of bone. Crest: Prominent ridge or elongated projection. Epicondyle: Typically roughened projection above condyle. Spinous process: Sharp, slender projection. Trochanter: Very large projection. Tubercle: Variably sized rounded projection. Tuberosity: Variably sized projection that has a rough, bumpy, service.

Describe the types of movements that can occur at synovial joints, noting which plane the motion takes place in

Flexion: A decrease in the angle between articulating bones. Usually occurs along sagittal plane. Extension: An increase in the angle between articulating bones, often to restore a part of the body to the anatomical position after it has been flexed. Usually occurs along sagittal plane. Hyperextension: Continuation of extension beyond the anatomical position. Examples include: bending the head backward at the atlanto-occipital and cervical intevertebral joints as in looking up at stars. Hyperextension of hinge joints, such as the elbow and knee joints is usually prevented by the arrangement of ligaments and the anatomical alignment of the bones. Abduction: The movement of a bone away from the midline. Usually occurs along the frontal plane. Ex: moving the humerus laterally at the shoulder joint, moving the palm laterally at the wrist joint, and moving the femur laterally at the hip joint. NOTE: The midline of the body is not used as a point of reference for abduction and adduction of the digits. Adduction: the movement of a bone toward the midline. Usually occurs along the frontal plane. Circumduction Rotation (medial + lateral): Movement of the distal end of a body part in a circle. Not an isolated movement by itself but rather a continuous sequence of flexion, abduction, extension, adduction, and rotation of the joint. It does not occur along a separate axis or plane of movement. Ex: moving the humerus in a circle at the shoulder joint. Elevation: Superior movement of a part of the body such as closing the mouth at the temporomandibular joint to elevate the mandible. Hyoid bones and ribs can be elevated or depressed. Depression: An inferior movement of a part of the body, such as opening the mouth to depress the mandible or returning shrugged shoulders to the anatomical position to depress the scapula and clavicle. Protraction: Movement of a part of the body anteriorly in the transverse plane. It's opposing movement is retraction. You can protract your mandible at the temporomandibular joint by thrusting it outward. Retraction: A movement of a protracted part of the body back to the anatomical position. Inversion: Movement f the sole medially at the intertarsal joints. The opposing movement is eversion. Physical therapists also refer to inversion combined with plantar flexion of the feed as supination. Eversion: A movement of the sole laterally at the intertarsal joints. Physical therapists also refer to eversion combined with dorisflexion of the feet as pronation. Dorsiflexion: The bending of the foot at ankle or talocrural joint in the direction of the dorsum. Dorsiflexion occuts when you stand on your heels. Its opposing movement is plantar flexion. Plantar flexion: Involves bending of the foot at the ankle joint in the direction of the plantar or inferior surface, as when you elevate your body by standing on your toes. Supination: A movement of the forearm at the proximal and distal radioulnar joints in which the palm is turned anteriorly. This position of the palms is one of the defining features of the anatomical position. It's opposing movement is pronation. Pronation: A movement of the forearm at the proximal and distal radioulnar joints in which the distal end of the radius crosses over the distal end of the ulna and the palm is turned posteriorly. Opposition: The movement of the thumb at the carpometacarpal joint in which the thumb moves across the plam to touch the tips of the fingers on the same hand. These opposable thumbs allow the distinctive digital movement that gives humans and other primates the ability to grasp and manipulate objects very precisely.

Describe the structures and functions of the diencephalon

Forms the thalamus, hypothalamus, epithalamus, and third ventricle. Thalamus: Relays almost all sensory input to cerebral cortex. Contributes to motor functions by transmitting information from cerebellum and basal nuclei to primary motor area of cerebral cortex. Plays role in maintenance of consciousness. Hypothalamus: Controls and integrates activities of autonomic nervous system. Produces hormones, including releasing hormones, inhibiting hormones, oxytocin, and antidiuretic hormone (ADH). Regulates emotional and behavioral patterns (together with limbic system). Contains feeding and satiety centers (regulate eating), thirst center (regulates drinking), and suprachiasmatic nucleus (regulates circadian rhythms). Controls body temperature by serving as body's thermostat. Epithalamus: Consists of pineal gland (secretes melatonin) and habenular nuclei (involved in olfaction).

Classify sensory receptors based on microscopic structure, location, and type of stimulus detected

Free nerve endings of first-order neurons are bare (not encapsulated) dendrites; they lack any structural specializations that can be seen under a light microscope. Receptors for pain, temperature, tickle, itch, and some touch sensations are free nerve endings. Encapsulated first-order neurons Receptors for other somatic and visceral sensations, such as pressure, vibration, and some touch sensations, are encapsulated nerve endings. Their dendrites are enclosed in a connective tissue capsule that has a distinctive microscopic structure—for example, lamellated corpuscles. The different types of capsules enhance the sensitivity or specificity of the receptor Separate cell that synapses with first-order neuron: Sensory receptors for some special senses are specialized, separate cells that synapse with sensory neurons. These include hair cells for hearing and equilibrium in the inner ear, gustatory receptors in taste buds and photoreceptors in the retina of the eye for vision. The olfactory receptors for the sense of smell are not separate cells; instead, they are located in olfactory cilia, which are hair like structures that project from the dendrite of an olfactory receptor cell (a type of neuron). Exteroceptors: are located at or near the external surface of the body; they are sensitive to stimuli originating outside the body and provide information about the external environment. The sensations of hearing, vision, smell, taste, touch, pressure, vibration, temperature, and pain are conveyed by exteroceptors. Interoceptors: or visceroceptors are located in blood vessels, visceral organs, muscles, and the nervous system and monitor conditions in the internal environment. The nerve impulses produced by interoceptors usually are not consciously perceived; occasionally, however, activation of interoceptors by strong stimuli may be felt as pain or pressure. Proprioceptors: are located in muscles, tendons, joints, and the inner ear. They provide information about body position, muscle length and tension, and the position and movement of your joints. Mechanoreceptors: are sensitive to mechanical stimuli such as the deformation, stretching, or bending of cells. Mechanoreceptors provide sensations of touch, pressure, vibration, proprioception, and hearing and equilibrium. They also monitor the stretching of blood vessels and internal organs. Thermoreceptors: detect changes in temperature. Nociceptors: respond to painful stimuli resulting from physical or chemical damage to tissue. Photoreceptors: Photoreceptors Chemoreceptors: detect chemicals in the mouth (taste), nose (smell), and body fluids. Osmoreceptors: detect the osmotic pressure of body fluids.

Recall the structure and function of five main types of cell junctions

Gap junction: At gap junctions, membrane proteins called connexins form tiny fluid‐filled tunnels called connexons that connect neighboring cells. The plasma membranes of gap junctions are not fused together as in tight junctions but are separated by a very narrow intercellular gap (space). Through the connexons, ions and small molecules can diffuse from the cytosol of one cell to another, but the passage of large molecules such as vital intracellular proteins is prevented. The transfer of nutrients, and perhaps wastes, takes place through gap junctions in avascular tissues such as the lens and cornea of the eye. Gap junctions allow the cells in a tissue to communicate with one another. In a developing embryo, some of the chemical and electrical signals that regulate growth and cell differentiation travel via gap junctions. Gap junctions also enable nerve or muscle impulses to spread rapidly among cells, a process that is crucial for the normal operation of some parts of the nervous system and for the contraction of muscle in the heart, gastrointestinal tract, and uterus. Hemidesmosome: resemble desmosomes, but they do not link adjacent cells. The name arises from the fact that they look like half of a desmosome. However, the transmembrane glycoproteins in hemidesmosomes are integrins rather than cadherins. On the inside of the plasma membrane, integrins attach to intermediate filaments made of the protein keratin. On the outside of the plasma membrane, the integrins attach to the protein laminin, which is present in the basement membrane (discussed shortly). Thus, hemidesmosomes anchor cells not to each other but to the basement membrane. Desmosome: Like adherens junctions, desmosomes contain plaque and have transmembrane glycoproteins (cadherins) that extend into the intercellular space between adjacent cell membranes and attach cells to one another. However, unlike adherens junctions, the plaque of desmosomes does not attach to microfilaments. Instead, a desmosome plaque attaches to elements of the cytoskeleton known as intermediate filaments, which consist of the protein keratin. The intermediate filaments extend from desmosomes on one side of the cell across the cytosol to desmosomes on the opposite side of the cell. This structural arrangement contributes to the stability of the cells and tissue. These spot weld-like junctions are common among the cells that make up the epidermis (the outermost layer of the skin) and among cardiac muscle cells in the heart. Desmosomes prevent epidermal cells from separating under tension and cardiac muscle cells from pulling apart during contraction. Adherens junction: contain plaque, a dense layer of proteins on the inside of the plasma membrane that attaches both to membrane proteins and to microfilaments of the cytoskeleton. Transmembrane glycoproteins called cadherins join the cells. Each cadherin inserts into the plaque from the opposite side of the plasma membrane, partially crosses the intercellular space (the space between the cells), and connects to cadherins of an adjacent cell. In epithelial cells, adherens junctions often form extensive zones called adhesion belts because they encircle the cell similar to the way a belt encircles your waist. Adherens junctions help epithelial surfaces resist separation during various contractile activities, as when food moves through the intestines. Tight junction: consist of weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells. Cells of epithelial tissue that lines the stomach, intestines, and urinary bladder have many tight junctions. They inhibit the passage of substances between cells and prevent the contents of these organs from leaking into the blood or surrounding tissues.

Describe the internal anatomy of the spine

Gray matter horns: The gray matter on each side of the spinal cord is subdivided into regions called horns. Gray posterior horns (dorsal): Contain axons of incoming sensory neurons as well as cell bodies and axons of interneurons. Gray anterior horns (ventral): Contain somatic motor nuclei which are clusters of cell bodies of somatic motor neurons that provide nerve impulses for contraction of skeletal muscles. ****The anterior gray horn, posterior gray horn and lateral gray horns do NOT contain myelinated fibers. White matter columns: The white matter of the spinal cord is also organized into regions. The anterior and posterior gray horns divide the white matter on each side into three broad areas called columns: anterior white columns, posterior white columns, and lateral white columns. ***White matter of the spinal cord is located around the outside. Central canal: In the center of the gray commissure. It extends the entire length of the spinal cord and is filled with CSF. At the superior end, the central canal is continuous with the fourth ventricle in the medulla oblongata of the brain.

Sensory and motor tracts within the spinal cord

Have names that indicate the location of the initiation and termination of the nerve impulses they conduct

Describe the structure and function of the limbic system

Hippocampus: A portion of the parahippocampal gyrus that extends into the floor of the lateral ventricle. Cingulate gyrus: The so-called limbic lobe is a rim of cerebral cortex on the medial surface of each hemisphere. It includes the cingulate gyrus, which lies about the corpus callosum, and the parahippocampal. Amygdala: Composed of several groups of neurons located close to the tail of the caudate nucleus.

Describe hyposmia

Hyposmia a reduced ability to smell, affects half of those over age 65 and 75% of those over age 80. Hyposmia also can be caused by neurological changes, such as a head injury, Alzheimer's disease, or Parkinson's disease; certain drugs, such as antihistamines, analgesics, or steroids; and the damaging effects of smoking.

Distinguish between isotonic (concentric + eccentric) and isometric contractions

In an isotonic contraction, the tension developed in the muscle remains almost constant while the muscle changes its length. Isotonic contractions are used for body movements and for moving objects. There are two types of isotonic contraction: concentric and eccentric. If the tension generated in a concentric isotonic contraction is great enough to overcome the resistance of the object being moved, the muscle shortens and pulls on another structure, such as a tendon, to produce movement and to reduce the angle at a joint. When the length of a muscle increases during a contraction, the contraction is eccentric. The tension is exerted by the myosin cross bridges and resists movement of a load and slows the lengthening process. Repeated eccentric contractions produce more muscle damage and more delayed onset muscle soreness than concentric contractions In an isometric contraction, the tension generated is not enough to exceed the resistance of an object to be moved, and the muscle does not change its length. These contractions are important for maintaining posture and for supporting objects in a fixed position. They do not result in body movement, but they do expend energy. These type of contractions are important because they stabilize some joints as others are moved. Most activities include both isotonic and isometric contractions.

Describe the major parasympathetic responses

In contrast to the fight-or-flight activities of the sympathetic division, the parasympathetic division enhances rest-and-digest activities. Parasympathetic responses support body functions that conserve and restore body energy during times of rest and recovery. In the quiet intervals between periods of exercise, parasympathetic impulses to the digestive glands and the smooth muscle of the gastrointestinal tract predominate over sympathetic impulses. This allows energy-supplying food to be digested and absorbed. At the same time, parasympathetic responses reduce body functions that support physical activity. The acronym SLUDD can be helpful in remembering five parasympathetic responses. It stands for salivation (S), lacrimation (L), urination (U), digestion (D), and defecation (D). All of these activities are stimulated mainly by the parasympathetic division. In addition to the increasing SLUDD responses other important parasympathetic responses are "three decreases": decreased heart rate, decreased diameter of airways (bronchoconstriction), and decreased diameter (constriction) of the pupils.

Explain how an image is formed by the eye

In some ways the eye is like a camera: Its optical elements focus an image of some object on a light-sensitive "film"—the retina—while ensuring the correct amount of light to make the proper "exposure." Three processes help the eye for an image: (1) the refraction or bending of light by the lens and cornea; (2) accommodation, the change in shape of the lens; and (3) constriction or narrowing of the pupil.

Explain how bone grows in length and thickness.

LENGTH: The growth in length of long bones involves the following two major events: (1) interstitial growth of cartilage on the epiphyseal side of the epiphyseal plate and (2) replacement of cartilage on the diaphyseal side of the epiphyseal plate with bone by endochondral ossification. Steps: 1) Zone of resting cartilage. This layer is nearest the epiphysis and consists of small, scattered chondrocytes. The term "resting" is used because the cells do not function in bone growth. Rather, they anchor the epiphyseal plate to the epiphysis of the bone. 2) Zone of proliferating cartilage. Slightly larger chondrocytes in this zone are arranged like stacks of coins. These chondrocytes undergo interstitial growth as they divide and secrete extracellular matrix. The chondrocytes in this zone divide to replace those that die at the diaphyseal side of the epiphyseal plate. 3) Zone of hypertrophic cartilage (hī‐per‐TRŌ‐fik). This layer consists of large, maturing chondrocytes arranged in columns. 4) Zone of calcified cartilage. The final zone of the epiphyseal plate is only a few cells thick and consists mostly of chondrocytes that are dead because the extracellular matrix around them has calcified. Osteoclasts dissolve the calcified cartilage, and osteoblasts and capillaries from the diaphysis invade the area. The osteoblasts lay down bone extracellular matrix, replacing the calcified cartilage by the process of endochondral ossification. Recall that endochondral ossification is the replacement of cartilage with bone. As a result, the zone of calcified cartilage becomes the "new diaphysis" that is firmly cemented to the rest of the diaphysis of the bone. THICKNESS: Like cartilage, bone can grow in thickness (diameter) only by appositional growth STEPS 1) At the bone surface, periosteal cells differentiate into osteoblasts, which secrete the collagen fibers and other organic molecules that form bone extracellular matrix. The osteoblasts become surrounded by extracellular matrix and develop into osteocytes. This process forms bone ridges on either side of a periosteal blood vessel. The ridges slowly enlarge and create a groove for the periosteal blood vessel. 2) Eventually, the ridges fold together and fuse, and the groove becomes a tunnel that encloses the blood vessel. The former periosteum now becomes the endosteum that lines the tunnel. 3) Osteoblasts in the endosteum deposit bone extracellular matrix, forming new concentric lamellae. The formation of additional concentric lamellae proceeds inward toward the periosteal blood vessel. In this way, the tunnel fills in, and a new osteon is created. 4) As an osteon is forming, osteoblasts under the periosteum deposit new circumferential lamellae, further increasing the thickness of the bone. As additional periosteal blood vessels become enclosed as in step 1, the growth process continues.

Head

Large round articulation surface supported by the neck of the bone

Condyle

Large round surface for smooth articulation surface

Which portion of the ventricular system is located in the cerebral hemisphere?

Lateral ventricle

Describe the layers of the epidermis and the cells that compose them

Layers: Stratum corneum,: Few to 50 or more rows of dead, flat keratinocytes that contain mostly keratin. Startum Lucidum: Present only in skin of fingertips, palms, and soles; consists of four to six rows of clear, flat, dead keratinocytes with large amounts of keratin. Stratum granulosum: Three to five rows of flattened keratinocytes, in which organelles are beginning to degenerate; cells contain the protein keratohyalin (converts keratin intermediate filaments into keratin) and lamellar granules (release lipid-rich, water-repellent secretion). Stratum spinosum: Eight to ten rows of many-sided keratinocytes with bundles of keratin intermediate filaments; contains projections of melanocytes and intraepidermal macrophages. Stratum basale: Deepest layer, composed of single row of cuboidal or columnar keratinocytes that contain scattered keratin intermediate filaments (tonofilaments); stem cells undergo cell division to produce new keratinocytes; melanocytes and tactile epithelial cells associated with tactile discs are scattered among keratinocytes. Types of cells: Keratinocyte: About 90% of epidermal cells are keratinocytes, which are arranged in four or five layers and produce the protein keratin. Recall from Chapter 4 that keratin is a tough, fibrous protein that helps protect the skin and underlying tissues from abrasions, heat, microbes, and chemicals. Keratinocytes also produce lamellar granules, which release a water-repellent sealant that decreases water entry and loss and inhibits the entry of foreign materials. Intraepidermal macrophage: or Langerhans cells arise from red bone marrow and migrate to the epidermis (Figure 5.2c), where they constitute a small fraction of the epidermal cells. They participate in immune responses mounted against microbes that invade the skin, and are easily damaged by UV light. Their role in the immune response is to help other cells of the immune system recognize an invading microbe and destroy it. Tactile epithelial cell: or Merkel cells, are the least numerous of the epidermal cells. They are located in the deepest layer of the epidermis, where they contact the flattened process of a sensory neuron (nerve cell), a structure called a tactile disc or Merkel disc (Figure 5.2d). Tactile epithelial cells and their associated tactile discs detect touch sensations. Melanocyte: About 8% of the epidermal cells are melanocytes, which develop from the ectoderm of a developing embryo and produce the pigment melanin. Their long, slender projections extend between the keratinocytes and transfer melanin granules to them. Melanin is a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging ultraviolet (UV) light. Once inside keratinocytes, the melanin granules cluster to form a protective veil over the nucleus, on the side toward the skin surface. In this way, they shield the nuclear DNA from damage by UV light. Although their melanin granules effectively protect keratinocytes, melanocytes themselves are particularly susceptible to damage by UV light.

Compare the basic types of ion channels, and explain how they relate to graded potentials and action potentials

Leak: Gated channels that randomly open and close. Found in nearly all cells, including dendrites, cell bodies, and axons of all types of neurons. Ligand-gated: Gated channels that open in response to binding of ligand (chemical) stimulus. Located in dendrites of some sensory neurons such as pain receptors and dendrites and cell bodies of interneurons and motor neurons. Mechanically-gated: Gated channels that open in response to mechanical stimulus (such as touch, pressure, vibration, or tissue stretching). Located in dendrites of some sensory neurons such as touch receptors, pressure receptors, and some pain receptors. Involved with the formation of a graded potential. Voltage-gated channels: Gated channels that open in response to voltage stimulus (change in membrane potential) Located in axons of all types of neurons.

Describe the cellular properties that permit communication among neurons and effectors

Like muscle fibers, neurons are electrically excitable. They communicate with one another using two types of electrical signals: (1) Graded potentials (described shortly) are used for short-distance communication only. (2) Action potentials (also described shortly) allow communication over long distances within the body. Recall that an action potential in a muscle fiber is called a muscle action potential. When an action potential occurs in a neuron (nerve cell), it is called a nerve action potential (nerve impulse). To understand the functions of graded potentials and action potentials, consider how the nervous system allows you to feel the smooth surface of a pen that you have picked up from a table. ** Action potentials occur on unmyelinated axons. Graded potentials occur on cell bodies and dendrites. Action potentials occur over short or long distances on myelinated axons. Graded potentials occur when ligand or mechanically-gated channels open.

Recall the structure, location, and function of various types of connective tissue

Mature connective tissue: The first type of mature connective tissue we will consider is connective tissue proper. This type of connective tissue is flexible and has a viscous ground substance with abundant fibers. Loose Connective Tissue: Areolar: Is one of the most widely distributed connective tissues; consists of fibers (collagen, elastic, reticular) arranged randomly and several kinds of cells (fibroblasts, macrophages, plasma cells, adipocytes, mast cells, and a few white blood cells) embedded in semifluid ground substance (hyaluronic acid, chondroitin sulfate, dermatan sulfate, and keratan sulfate). Location: In and around nearly every body structure (thus, called "packing material" of the body): in subcutaneous layer deep to skin; papillary (superficial) region of dermis of skin; lamina propria of mucous membranes; around blood vessels, nerves, and body organs. Function: Strength, elasticity, support. Adipose: has cells derived from fibroblasts (called adipocytes) that are specialized for storage of triglycerides (fats) as a large, centrally located droplet. Cell fills up with a single, large triglyceride droplet, and cytoplasm and nucleus are pushed to periphery of cell. With weight gain, amount of adipose tissue increases and new blood vessels form. Thus, an obese person has many more blood vessels than does a lean person, a situation that can cause high blood pressure, since the heart has to work harder. Most adipose tissue in adults is white adipose tissue (just described). Brown adipose tissue (BAT) is darker due to very rich blood supply and numerous pigmented mitochondria that participate in aerobic cellular respiration. BAT is widespread in the fetus and infant; adults have only small amounts. Location: Wherever areolar connective tissue is located: subcutaneous layer deep to skin, around heart and kidneys, yellow bone marrow, padding around joints and behind eyeball in eye socket. Function: Reduces heat loss through skin; serves as an energy reserve; supports and protects organs. In newborns, BAT generates heat to maintain proper body temperature. Adipose tissue is also an excellent source of stem cells, which are used in rejuvenation medicine to repair or replace damaged tissue. Reticular: Reticular connective tissue is a fine interlacing network of reticular fibers (thin form of collagen fiber) and reticular cells. Location: Stroma (supporting framework) of liver, spleen, lymph nodes; red bone marrow; reticular lamina of basement membrane; around blood vessels and muscles. Function: Forms stroma of organs; binds smooth muscle tissue cells; filters and removes worn‐out blood cells in spleen and microbes in lymph nodes. Dense connective tissue: regular: Dense regular connective tissue forms shiny white extracellular matrix; mainly collagen fibers regularly arranged in bundles with fibroblasts in rows between them. Collagen fibers (protein structures secreted by fibroblasts) are not living, so damaged tendons and ligaments heal slowly. Location: Forms tendons (attach muscle to bone), most ligaments (attach bone to bone), and aponeuroses (sheetlike tendons that attach muscle to muscle or muscle to bone). Function: Provides strong attachment between various structures. Tissue structure withstands pulling (tension) along long axis of fibers. irregular: Dense irregular connective tissue is made up of collagen fibers; usually irregularly arranged with a few fibroblasts. Location: Often occurs in sheets, such as fasciae (tissue beneath skin and around muscles and other organs), reticular (deeper) region of dermis of skin, fibrous pericardium of heart, periosteum of bone, perichondrium of cartilage, joint capsules, membrane capsules around various organs (kidneys, liver, testes, lymph nodes); also in heart valves. Function: Provides tensile (pulling) strength in many directions. Elastic: Elastic connective tissue contains predominantly elastic fibers with fibroblasts between them; unstained tissue is yellowish. Location: Lung tissue, walls of elastic arteries, trachea, bronchial tubes, true vocal cords, suspensory ligaments of penis, some ligaments between vertebrae. Function: Allows stretching of various organs; is strong and can recoil to original shape after being stretched. Elasticity is important to normal functioning of lung tissue (recoils in exhaling) and elastic arteries (recoil between heartbeats to help maintain blood flow). Supporting connective tissue Hyaline: Hyaline cartilage (hyalinos = glassy) contains a resilient gel as ground substance and appears in the body as a bluish‐white, shiny substance (can stain pink or purple when prepared for microscopic examination; fine collagen fibers are not visible with ordinary staining techniques); prominent chondrocytes are found in lacunae surrounded by perichondrium (exceptions: articular cartilage in joints and cartilage of epiphyseal plates, where bones lengthen during growth). Location: Most abundant cartilage in body; at ends of long bones, anterior ends of ribs, nose, parts of larynx, trachea, bronchi, bronchial tubes, embryonic and fetal skeleton. Function: Provides smooth surfaces for movement at joints, flexibility, and support; weakest type of cartilage and can be fractured. Fibrocatilage: Fibrocartilage has chondrocytes among clearly visible thick bundles of collagen fibers within extracellular matrix; lacks perichondrium. Location: Pubic symphysis (where hip bones join anteriorly), intervertebral discs, menisci (cartilage pads) of knee, portions of tendons that insert into cartilage. Function: Support and joining structures together. Strength and rigidity make it the strongest type of cartilage. Elastic: Elastic cartilage has chondrocytes in threadlike network of elastic fibers within extracellular matrix; perichondrium present. Location: Lid on top of larynx (epiglottis), part of external ear (auricle), auditory (eustachian) tubes. Function: Provides strength and elasticity; maintains shape of certain structures. Bone: compact: consists of osteons (haversian systems) that contain lamellae, lacunae, osteocytes, canaliculi, and central (haversian) canals. spongy: consists of thin columns called trabeculae; spaces between trabeculae are filled with red bone marrow. Location: Both compact and spongy bone tissue make up the various parts of bones of the body. Function: Support, protection, storage; houses blood‐forming tissue; serves as levers that act with muscle tissue to enable movement. Liquid connective tissue: This is the final type of mature connective tissue. A liquid connective tissue has a liquid as its extracellular matrix. Blood: consists of blood plasma and formed elements: red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes). Location: Within blood vessels (arteries, arterioles, capillaries, venules, veins), within chambers of heart. Function: Red blood cells: transport oxygen and some carbon dioxide; white blood cells: carry on phagocytosis and mediate allergic reactions and immune system responses; platelets: essential for blood clotting. Lymph: Lymph is the extracellular fluid that flows in lymphatic vessels. It is a liquid connective tissue that consists of several types of cells in a clear liquid extracellular matrix that is similar to blood plasma but with much less protein. The composition of lymph varies from one part of the body to another. For example, lymph leaving lymph nodes includes many lymphocytes, a type of white blood cell, in contrast to lymph from the small intestine, which has a high content of newly absorbed dietary lipids.

Identify the muscle compartments of the thigh

Medial (adductors): Adduct the femur at the hip joint. The adductor magnus, longus, brevis, and pectinous which are components of the medial compartment. The gracilis, the other muscle in the medial compartment, is a long, strap-like muscle on the medial aspect of the thigh and knee. This muscle not only adducts the thigh, but also medially rotates the thigh and flexes the leg at the knee joint. Anterior (extensors): Includes the quadriceps femoris and the sartorius. Posterior (flexors): Includes the biceps femoris, semitendinosus, and semimembranosus

Explain the basis of different skin colors

Melanocytes synthesize melanin from the amino acid tyrosine in the presence of an enzyme called tyrosinase. Synthesis occurs in an organelle called a melanosome. Exposure to ultraviolet (UV) light increases the enzymatic activity within melanosomes and thus increases melanin production. Both the amount and darkness of melanin increase on UV exposure, which gives the skin a tanned appearance and helps protect the body against further UV radiation. Melanin absorbs UV radiation, prevents damage to DNA in epidermal cells, and neutralizes free radicals that form in the skin following damage by UV radiation. Thus, within limits, melanin serves a protective function. In response to DNA damage, melanin production increases. As you will see later, exposing the skin to a small amount of UV light is actually necessary for the skin to begin the process of vitamin D synthesis. However, repeatedly exposing the skin to a large amount of UV light may cause skin cancer. A tan is lost when the melanin-containing keratinocytes are shed from the stratum corneum. Dark-skinned individuals have large amounts of melanin in the epidermis, so their skin color ranges from yellow to reddish-brown to black. Light-skinned individuals have little melanin in the epidermis. Thus, the epidermis appears translucent, and skin color ranges from pink to red depending on the oxygen content of the blood moving through capillaries in the dermis. The red color is due to hemoglobin, the oxygen-carrying pigment in red blood cells. Carotene is a yellow-orange pigment that gives egg yolks and carrots their color. This precursor of vitamin A, which is used to synthesize pigments needed for vision, is stored in the stratum corneum and fatty areas of the dermis and subcutaneous layer in response to excessive dietary intake. In fact, so much carotene may be deposited in the skin after eating large amounts of carotene-rich foods that the skin actually turns orange, which is especially apparent in light-skinned individuals. Decreasing carotene intake eliminates the problem.

Compare the functional classifications of exocrine glands

Merocrine: Secretions of merocrine glands are synthesized on ribosomes attached to rough ER; processed, sorted, and packaged by the Golgi complex; and released from the cell in secretory vesicles via exocytosis. Most exocrine glands of the body are merocrine glands. Examples include the salivary glands and pancreas. Apocrine: Apocrine glands accumulate their secretory product at the apical surface of the secreting cell. Then, that portion of the cell pinches off by exocytosis from the rest of the cell to release the secretion. The cell repairs itself and repeats the process. Electron microscopy has confirmed that this is the mechanism of secretion of milk fats in the mammary glands. Recent evidence reveals that the sweat glands of the skin, named apocrine sweat glands after this mode of secretion, actually undergo merocrine secretion. Holocrine: The cells of holocrine glands accumulate a secretory product in their cytosol. As the secretory cell matures, it ruptures and becomes the secretory product. Because the cell ruptures in this mode of secretion, the secretion contains large amounts of lipids from the plasma membrane and intracellular membranes. The sloughed off cell is replaced by a new cell. One example of a holocrine gland is a sebaceous gland of the skin.

Distinguish between monosynapic and polysnpatic spinal reflexes

Monosynaptic: A reflex pathway having only one synapse in the CNS. Polysynaptic: Involves more than two types of neurons and more than one CNS synapse.

Compare three main structural classifications of neurons

Multipolar: usually have several dendrites and one axon (Figure 12.3a). Most neurons in the brain and spinal cord are of this type, as well as all motor neurons (described shortly). Bipolar: have one main dendrite and one axon. They are found in the retina of the eye, the inner ear, and the olfactory area of the brain. Unipolar: have dendrites and one axon that are fused together to form a continuous process that emerges from the cell body These neurons are more appropriately called pseudounipolar neurons because they begin in the embryo as bipolar neurons. During development, the dendrites and axon fuse together and become a single process. The dendrites of most unipolar neurons function as sensory receptors that detect a sensory stimulus such as touch, pressure, pain, or thermal stimuli. The trigger zone for nerve impulses in a unipolar neuron is at the junction of the dendrites and axon. The impulses then propagate toward the synaptic end bulbs. The cell bodies of most unipolar neurons are located in the ganglia of spinal and cranial nerves.

Describe the receptors for proprioception

Muscle spindles: are the proprioceptors that monitor changes in the length of skeletal muscles and participate in stretch reflexes. By adjusting how vigorously a muscle spindle responds to stretching of a skeletal muscle, the brain sets an overall level of muscle tone, the small degree of contraction that is present while the muscle is at rest. Each muscle spindle consists of several slowly adapting sensory nerve endings that wrap around 3 to 10 specialized muscle fibers, called intrafusal fibers Tendon organs: Tendon organs are slowly adapting receptors located at the junction of a tendon and a muscle. By initiating tendon reflexes, tendon organs protect tendons and their associated muscles from damage due to excessive tension. (When a muscle contracts, it exerts a force that pulls the points of attachment of the muscle at either end toward each other. This force is the muscle tension.) Each tendon organ consists of a thin capsule of connective tissue that encloses a few tendon fascicles (bundles of collagen fibers). Penetrating the capsule are one or more sensory nerve endings that entwine among and around the collagen fibers of the tendon. When tension is applied to a muscle, the tendon organs generate nerve impulses that propagate into the CNS, providing information about changes in muscle tension. The resulting tendon reflexes decrease muscle tension by causing muscle relaxation. Joint kinesthetic receptors: Several types of joint kinesthetic receptors are present within and around the articular capsules of synovial joints. Free nerve endings and type II cutaneous mechanoreceptors in the capsules of joints respond to pressure. Small lamellated corpuscles in the connective tissue outside articular capsules respond to acceleration and deceleration of joints during movement. Joint ligaments contain receptors similar to tendon organs that adjust reflex inhibition of the adjacent muscles when excessive strain is placed on the joint.

Contrast how negative and positive feedback systems control homeostasis

Negative Feedback Systems: A negative feedback system reverses a change in a controlled condition. Consider the regulation of blood pressure. Blood pressure (BP) is the force exerted by blood as it presses against the walls of blood vessels. When the heart beats faster or harder, BP increases. If some internal or external stimulus causes blood pressure (controlled condition) to rise, the following sequence of events occurs. Baroreceptors (the receptors), pressure-sensitive nerve cells located in the walls of certain blood vessels, detect the higher pressure. The baroreceptors send nerve impulses (input) to the brain (control center), which interprets the impulses and responds by sending nerve impulses (output) to the heart and blood vessels (the effectors). Heart rate decreases and blood vessels dilate (widen), which cause BP to decrease (response). This sequence of events quickly returns the controlled condition—blood pressure—to normal, and homeostasis is restored. Notice that the activity of the effector causes BP to drop, a result that negates the original stimulus (an increase in BP). This is why it is called a negative feedback system. ****Blood concentration of thyroid hormones increase above a certain level, thyroid releasing hormone (TRH) neurons in the hypothalamus are inhibited and stop secreting TRH. Positive Feedback: Unlike a negative feedback system, a positive feedback system tends to strengthen or reinforce a change in one of the body's controlled conditions. In a positive feedback system, the response affects the controlled condition differently than in a negative feedback system. The control center still provides commands to an effector, but this time the effector produces a physiological response that adds to or reinforces the initial change in the controlled condition. The action of a positive feedback system continues until it is interrupted by some mechanism. Normal childbirth provides a good example of a positive feedback system. The first contractions of labor (stimulus) push part of the fetus into the cervix, the lowest part of the uterus, which opens into the vagina. Stretch-sensitive nerve cells (receptors) monitor the amount of stretching of the cervix (controlled condition). As stretching increases, they send more nerve impulses (input) to the brain (control center), which in turn causes the pituitary gland to release the hormone oxytocin (output) into the blood. Oxytocin causes muscles in the wall of the uterus (effector) to contract even more forcefully. The contractions push the fetus farther down the uterus, which stretches the cervix even more. The cycle of stretching, hormone release, and ever-stronger contractions is interrupted only by the birth of the baby. Then, stretching of the cervix ceases and oxytocin is no longer released. ***depolarization causes sodium channels to open and the opening of sodium channels causes the membrane to depolarize. ***increasing strength of uterine contractions in response to cervical stretch

Define neuroglia and compare the different types found in the CNS + PNS

Neuroglia are smaller cells, but they greatly outnumber neurons. They support, nourish, and protect neurons, and maintain the interstitial fluid that bathes them. Unlike neurons, neuroglia continue to divide throughout one's lifetime. CNS: Neuroglia of the CNS can be classified on the basis of size, cytoplasmic processes, and intracellular organization into four types: astrocytes, oligodendrocytes, microglia, ependymal cells. -Astrocytes: Star shaped cells have many processes and are the largest and most numerous of the neuroglia. There are two types: protoplasmic and fibrous. Protoplasmic have many short branching processes and are located mainly in gray matter. Fibrous have many long unbranched processes are located mainly in white matter. The processes of astrocytes make contact with blood capillaries, neurons, and the pia mater. Functions of astrocytes include the following: 1) They contain microfilaments that give them considerable strength, which enables them to support neurons. 2) Processes of astrocytes wrapped around blood capillaries isolate neurons of the CNS from various potentially harmful substances in blood by secreting chemicals that maintain the unique selective permeability characteristics of the endothelial cells of the capillaries. In effect, the endothelial cells create a blood-brain barrier, which restricts the movement of substances between the blood and interstitial fluid of the CNS. 3) In the embryo, astrocytes secrete chemicals that appear to regulate the growth, migration, and interconnection among neurons in the brain. 4) Astrocytes help to maintain the appropriate chemical environment for the generation of nerve impulses. For example, they regulate the concentration of important ions such as K+; take up excess neurotransmitters; and serve as a conduit for the passage of nutrients and other substances between blood capillaries and neurons. 5) Astrocytes may also play a role in learning and memory by influencing the formation of neural synapses Oligodendrocytes: resemble astrocytes but are smaller and contain fewer processes. responsible for forming and maintaining the myelin sheath around CNS axons. As you will see shortly, the myelin sheath is a multilayered lipid and protein covering around some axons that insulates them and increases the speed of nerve impulse conduction. Microglia: These neuroglia are small cells with slender processes that give off numerous spinelike projections. Like tissue macrophages, they remove cellular debris formed during normal development of the nervous system and phagocytize microbes and damaged nervous tissue. Ependymal Cells: cuboidal to columnar cells arranged in a single layer that possess microvilli and cilia. These cells line the ventricles of the brain and central canal of the spinal cord (spaces filled with cerebrospinal fluid, which protects and nourishes the brain and spinal cord). Functionally, ependymal cells produce, possibly monitor, and assist in the circulation of cerebrospinal fluid. They also form the blood-cerebrospinal fluid barrier PNS: Neuroglia of the PNS completely surround axons and cell bodies. These two types of glial cells in the PNS are schwann cells and satellite cells. Schwann Cells: These cells encircle PNS axons. Like oligodendrocytes, they form the myelin sheath around axons. Each Schwann cell myelinates a single axon. Schwann cell can also enclose as many as 20 or more unmyelinated axons (axons that lack a myelin sheath). Schwann cells participate in axon regeneration, which is more easily accomplished in the PNS than in the CNS Satellite Cells: These flat cells surround the cell bodies of neurons of PNS ganglia. Besides providing structural support, satellite cells regulate the exchanges of materials between neuronal cell bodies and interstitial fluid. **** Neuroglial cells do NOT generate graded potentials

Describe cholinergic and adrenergic receptors

Nicotinic: present in the plasma membrane of dendrites and cell bodies of both sympathetic and parasympathetic postganglionic neurons, the plasma membranes of chromaffin cells of the adrenal medullae, and in the motor end plate at the neuromuscular junction. They are so named because nicotine mimics the action of ACh by binding to these receptors. (Nicotine, a natural substance in tobacco leaves, is not a naturally occurring substance in humans and is not normally present in nonsmokers.) Muscarinic: are present in the plasma membranes of all effectors (smooth muscle, cardiac muscle, and glands) innervated by parasympathetic postganglionic axons. In addition, most sweat glands receive their innervation from cholinergic sympathetic postganglionic neurons and possess muscarinic receptors. These receptors are so named because a mushroom poison called muscarine mimics the actions of ACh by binding to them. Nicotine does not activate muscarinic receptors, and muscarine does not activate nicotinic receptors, but ACh does activate both types of cholinergic receptors. Alpha and Beta adrenergic receptors: Adrenergic receptors bind both norepinephrine and epinephrine. The norepinephrine can either be released as a neurotransmitter by sympathetic postganglionic neurons or released as a hormone into the blood by chromaffin cells of the adrenal medullae; epinephrine is released as a hormone. The two main types of adrenergic receptors are alpha (α) receptors and beta (β) receptors, which are found on visceral effectors innervated by most sympathetic postganglionic axons. These receptors are further classified into subtypes—α1, α2, β1, β2, and β3—based on the specific responses they elicit and by their selective binding of drugs that activate or block them. Although there are some exceptions: activation of α1 and β1 receptors generally produces excitation, and activation of α2 and β2 receptors causes inhibition of effector tissues. β3 receptors are present only on cells of brown adipose tissue, where their activation causes thermogenesis (heat production). Cells of most effectors contain either alpha or beta receptors; some visceral effector cells contain both. Norepinephrine stimulates alpha receptors more strongly than beta receptors; epinephrine is a potent stimulator of both alpha and beta receptors. **** Alpha 1 receptors are located on the sweat gland cells of only the palms and soles.

Describe the structure of the olfactory receptors and other cells involved in olfaction

Olfactory receptor cells are the first-order neurons of the olfactory pathway. Each olfactory receptor cell is a bipolar neuron with an exposed knob-shaped dendrite and an axon projecting through the cribriform plate that ends in the olfactory bulb. Extending from the dendrite of an olfactory receptor cell are several nonmotile olfactory cilia, which are the sites of olfactory transduction. (Recall that transduction is the conversion of stimulus energy into a graded potential in a sensory receptor.) Within the plasma membranes of the olfactory cilia are olfactory receptors proteins that detect inhaled chemicals. Chemicals that bind to and stimulate the olfactory receptors in the olfactory cilia are called odorants. Olfactory receptor cells respond to the chemical stimulation of an odorant molecule by producing a generator potential, thus initiating the olfactory response. Supporting cells are columnar epithelial cells of the mucous membrane lining the nose. They provide physical support, nourishment, and electrical insulation for the olfactory receptor cells and help detoxify chemicals that come in contact with the olfactory epithelium. Basal cells are stem cells located between the bases of the supporting cells. They continually undergo cell division to produce new olfactory receptor cells, which live for only about two months before being replaced. This process is remarkable considering that olfactory receptor cells are neurons, and as you have already learned, mature neurons are generally not replaced. Within the connective tissue that supports the olfactory epithelium are olfactory glands or Bowman's glands, which produce mucus that is carried to the surface of the epithelium by ducts. The secretion moistens the surface of the olfactory epithelium and dissolves odorants so that transduction can occur. Both supporting cells of the nasal epithelium and olfactory glands are innervated by parasympathetic neurons within branches of the facial (VII) nerve, which can be stimulated by certain chemicals. Impulses in these nerves in turn stimulate the lacrimal glands in the eyes and nasal mucous glands. The result is tears and a runny nose after inhaling substances such as pepper or the vapors of household ammonia.

Explain the process of olfactory transduction

Olfactory receptor cells react to odorant molecules in the same way that most sensory receptors react to their specific stimuli: A receptor potential (depolarization) develops and triggers one or more nerve impulses. This process, called olfactory transduction, occurs in the following way: Binding of an odorant to an olfactory receptor protein in an olfactory cilium stimulates a membrane protein called a G protein. The G protein, in turn, activates the enzyme adenylyl cyclase to produce a substance called cyclic adenosine monophosphate (cAMP), a type of second messenger. The cAMP opens a cation channel that allows Na+ and Ca2+ to enter the cytosol, which causes a depolarizing receptor potential to form in the membrane of the olfactory receptor cell. If the depolarization reaches threshold, an action potential is generated along the axon of the olfactory receptor cell.

Outline the neural pathway for olfaction

On each side of the nose, some 40 or so bundles of axons of olfactory receptor cells form the right and left olfactory (I) nerves. The olfactory nerves pass through the olfactory foramina of the cribriform plate of the ethmoid bone and extend to parts of the brain known as the olfactory bulbs, which contain ball-like arrangements called glomeruli. Within each glomerulus, axons of olfactory receptor cells converge onto mitral cells—the second order neurons of the olfactory pathway. Each glomerulus receives input from only one type of olfactory receptor. This allows the mitral cells of a particular glomerulus to convey information about a select group of odorants to the remaining parts of the olfactory pathway. The axons of the mitral cells form the olfactory tract. Some of the axons of the olfactory tract project to the primary olfactory area in the temporal lobe of the cerebral cortex, where conscious awareness of smell occurs. Olfactory sensations are the only sensations that reach the cerebral cortex without first synapsing in the thalamus. Other axons of the olfactory tract project to the limbic system; these neural connections account for our emotional responses to odors. From the olfactory cortex, a pathway extends via the thalamus to the orbitofrontal cortex in the frontal lobe, where odor identification and discrimination occur. People who suffer damage in this area have difficulty identifying different odors. Positron emission tomography (PET) studies suggest some degree of hemispheric lateralization: The orbitofrontal cortex of the right hemisphere exhibits greater activity during olfactory processing than the corresponding area in the left hemisphere. ****** Order of the olfactory pathway: Odorant binds to olfactory receptor protein, g protein activates cAMP, second messenger opens cation channels Na+ and Ca2+, depolarization of olfactory receptor cells occurs

Explain how blood calcium level is regulated and its importance in the body.

One way to maintain the level of calcium in the blood is to control the rates of calcium resorption from bone into blood and of calcium deposition from blood into bone. Both nerve and muscle cells depend on a stable level of calcium ions (Ca2+) in extracellular fluid to function properly. Blood plasma level is closely regulated between 9-11 mg/100 mL. Even small changes in Ca2+ concentration outside this range may prove fatal—the heart may stop (cardiac arrest) if the concentration goes too high, or breathing may cease (respiratory arrest) if the level falls too low. The role of bone in calcium homeostasis is to help "buffer" the blood Ca2+ level, releasing Ca2+ into blood plasma (using osteoclasts) when the level decreases, and absorbing Ca2+ (using osteoblasts) when the level rises. Calcium is regulated primarily by the hormone PTH (parathyroid hormone) secreted by the parathyroid glands. It increases blood Ca 2+ levels (negative feedback). If blood calcium is low, PTH gland receptors detect this change and increase their production of a molecule known as cyclic AMP. PTH recognizes cAMP and then, and ramps up synthesis of PTH which releases more into the blood, therefore increasing Ca2+. Higher PTH increases the number and activity of osteoclasts, which step up the place of bone resorption. The resulting release of Ca2+ from bone into blood returns the blood Ca2+ level to normal. ***************************PT gland cells are the receptors and respond to low blood calcium levels. cAMP input activates the control center when blood calcium is low. Osteoblasts and kidney cells are the effectors of PTH. The kidney increases reabsorption of calcium in response to PTH. Calcitriol is secreted in response to PTHs effects on the kidneys.

Sequence of development of bone cells

Osteoprogenitor cells --> osteoblasts --> osteocytes

Identify common chemical elements and their significance in humans

Oxygen (O)65.0Part of water and many organic (carbon‐containing) molecules; used to generate ATP, a molecule used by cells to temporarily store chemical energy. Carbon (C)18.5Forms backbone chains and rings of all organic molecules: carbohydrates, lipids (fats), proteins, and nucleic acids (DNA and RNA). Hydrogen (H)9.5Constituent of water and most organic molecules; ionized form (H+) makes body fluids more acidic. Nitrogen (N)3.2Component of all proteins and nucleic acids. Calcium (Ca)1.5Contributes to hardness of bones and teeth; ionized form (Ca2+) needed for blood clotting, release of some hormones, contraction of muscle, and many other processes. Phosphorus (P)1.0Component of nucleic acids and ATP; required for normal bone and tooth structure. Potassium (K)0.35Ionized form (K+) is the most plentiful cation (positively charged particle) in intracellular fluid; needed to generate action potentials. Sulfur (S)0.25Component of some vitamins and many proteins. Sodium (Na)0.2Ionized form (Na+) is the most plentiful cation in extracellular fluid; essential for maintaining water balance; needed to generate action potentials. Chlorine (Cl)0.2Ionized form (Cl−) is the most plentiful anion (negatively charged particle) in extracellular fluid; essential for maintaining water balance. Magnesium (Mg)0.1Ionized form (Mg2+) needed for action of many enzymes (molecules that increase the rate of chemical reactions in organisms). Iron (Fe)0.005Ionized forms (Fe2+ and Fe3+) are part of hemoglobin (oxygen‐carrying protein in red blood cells) and some enzymes.

Describe the six types of synovial joints.

Plane: Flat or slightly curved articulating surfaces of bones in a plane joint. They permit back and forth movement. Biaxial or triaxial Hinge: A hinge joint is when the convex surface of one bone fits into the concave surface of another. They produce an angular, opening and closing motion like the hinge of a door. They are uniaxial because they allow motion around a single axis. They permit only flexion and extension. Examples are the knee, elbow, ankle, and interphalangeal joints. Pivot: When the rounded or pointed surface of one bone articulates with a ring formed partly by another bone and partly by a ligament. Uniaxial because allows rotation only around its own longitudinal axis. Examples include the atlanto-axial joint (shaking your head) and the radioulnar joints. Condyloid: When the convex oval-shaped projection of one bone fits into the oval shaped depression of another bone. Biaxial because the movement it permits is around to axes (flexion-extension and abduction-adduction) plus limited circumduction. Examples include the wrist and metacarpophalangeal joints. Saddle: When the articular surface of one bone is saddle-shaped and the articular surface of the other bone fits into the saddle as a sitting rider would sit. The movements a t a saddle joint are the same as those at a condyloid joint: biaxial. Examples include carpometacarpal joint between the trapezium of the carpus and metacarpal of the thumb. Ball-and-socket: Consists of the ball-like surface of one bone fitting into a cuplike depression of another bone. They are considered to be triaxial, permitting movements around three axes: flexion-extension, abduction-adduction, and rotation. Examples are the shoulder and hip joints.

Define anatomical planes, anatomical sections, and directional terms used to describe the body

Planes/Sections: A sagittal plane is a vertical plane that divides the body or an organ into right and left sides. More specifically, when such a plane passes through the midline of the body or an organ and divides it into equal right and left sides, it is called a midsagittal plane or a median plane. The midline is an imaginary vertical line that divides the body into equal left and right sides. If the sagittal plane does not pass through the midline but instead divides the body or an organ into unequal right and left sides, it is called a para sagittal plane. A frontal or coronal plane divides the body or an organ into anterior (front) and posterior (back) portions. A transverse plane divides the body or an organ into superior (upper) and inferior (lower) portions. Other names for a transverse plane are a cross-sectional or horizontal plane. Sagittal, frontal, and transverse planes are all at right angles to one another. An oblique plane by contrast, passes through the body or an organ at an oblique angle (any angle other than a 90-degree angle). Directional Terms: Superior (soo′-PĒR-ē-or) (cephalic or cranial) Toward the head, or the upper part of a structure. The heart is superior to the liver. Inferior (in-FĒ-rē-or) (caudal)Away from the head, or the lower part of a structure.The stomach is inferior to the lungs. Anterior (ventral): Nearer to or at the front of the body.The sternum (breastbone) is anterior to the heart. Posterior (dorsal): Nearer to or at the back of the body.The esophagus (food tube) is posterior to the trachea (windpipe). Medial: Nearer to the midline (an imaginary vertical line that divides the body into equal right and left sides).The ulna is medial to the radius. Lateral: Farther from the midline.The lungs are lateral to the heart. Intermediate: Between two structures.The transverse colon is intermediate to the ascending and descending colons. Ipsilateral: On the same side of the body as another structure.The gallbladder and ascending colon are ipsilateral. Contralateral: On the opposite side of the body from another structure.The ascending and descending colons are contralateral. Proximal: Nearer to the attachment of a limb to the trunk; nearer to the origination of a structure.The humerus (arm bone) is proximal to the radius. Distal: Farther from the attachment of a limb to the trunk; farther from the origination of a structure.The phalanges (finger bones) are distal to the carpals (wrist bones). Superficial(external): Toward or on the surface of the body.The ribs are superficial to the lungs. Deep (Internal): Away from the surface of the body.The ribs are deep to the skin of the chest and back.

Describe the importance of calcium in muscles

Plays a major role in contraction and relaxation of muscles. Voltage gated Ca2+ channels are located in the T-tubule membrane and are arranged in tetrads. The main role of these channels are to serve as voltage sensors that trigger the opening of the Ca2+ release channels. Ca2_ release channels are present in the SR. When a skeletal muscle fiber is at rest, the part of the Ca release channel that extends into the sarcoplasm is blocked by a given cluster of voltage gated Ca channels, preventing CA from leaving the SR. When a skeletal muscle is excited and an action potential travels along the T tubule, the voltage gated Ca channels detect the change in voltage and undergo a change that causes Ca release channels to open. Once this occurs, a large amount of Ca flows into the sarcoplasm around thick and think filaments. In short, all of this leads to contraction. Calsequestrin bind to Ca 2+ which allows even more Ca2+ to be stored within the SR. In a relaxed muscle fiber, the concentration of Ca is 10000 times higher in the SR than in the sarcoplasm. ************Muscle contractions, nerve signaling, blood clotting, and enzymatic reactions

Recall information conveyed by major somatic sensory pathways

Posterior column-medial lemniscus: Cuneate fasciculus conveys nerve impulses for touch, pressure, vibration, and conscious proprioception from upper limbs, upper trunk, neck, and posterior head, and gracile fasciculus conveys nerve impulses for touch, pressure, vibration, and conscious proprioception from lower limbs and lower trunk. Axons of first-order neurons from one side of body form posterior column on same side and end in medulla, where they synapse with dendrites and cell bodies of second-order neurons. Axons of second-order neurons decussate, enter medial lemniscus on opposite side, and extend to thalamus. Third-order neurons transmit nerve impulses from thalamus to primary somatosensory area on side opposite the site of stimulation. Anterolateral (Spinothalamic): Conveys nerve impulses for pain, cold, warmth, itch, and tickle from limbs, trunk, neck, and posterior head. Axons of first-order neurons from one side of body synapse with dendrites and cell bodies of second-order neurons in posterior gray horn on same side of body. Axons of second-order neurons decussate, enter spinothalamic tract on opposite side, and extend to thalamus. Third-order neurons transmit nerve impulses from thalamus to primary somatosensory area on side opposite the site of stimulation. Trigeminothalamic: Conveys nerve impulses for touch, pressure, vibration, pain, cold, warmth, itch, and tickle from face, nasal cavity, oral cavity, and teeth to the cerebral cortex. Axons of first-order neurons from one side of head synapse with dendrites and cell bodies of second-order neurons in pons and medulla on same side of head. Axons of second-order neurons decussate, enter trigeminothalamic tract on opposite side, and extend to thalamus. Third-order neurons transmit nerve impulses from thalamus to primary somatosensory area on side opposite the site of stimulation. Anterior and posterior spinocerebellar tracts: Convey nerve impulses from proprioceptors in trunk and lower limb of one side of body to same side of cerebellum. Proprioceptive input informs cerebellum of actual movements, allowing it to coordinate, smooth, and refine skilled movements and maintain posture and balance.

Describe taste aversion

Probably because of taste projections to the hypothalamus and limbic system, there is a strong link between taste and pleasant or unpleasant emotions. Sweet foods evoke reactions of pleasure while bitter ones cause expressions of disgust, even in newborn babies. This phenomenon is the basis for taste aversion, in which people and animals quickly learn to avoid a food if it upsets the digestive system. The advantage of avoiding foods that cause such illness is longer survival. However, the drugs and radiation treatments used to combat cancer often cause nausea and gastrointestinal upset regardless of what foods are consumed. Thus, cancer patients may lose their appetite because they develop taste aversions for most foods.

Describe four key functions of muscular tissue.

Producing movement: Movements of the whole body such as walking or running, and localized movements such as grasping a pencil, keyboarding, or nodding the head rely on the functioning of skeletal muscles, bones, and joints. Stabilizing position: Skeletal muscle contractions stabilize the joints and help maintain body positions such as standing or sitting. Postural muscles contract simultaneously while you are awake. Moving substances within the body: Storage is accomplished by sustained contractions of ringlike bands of smooth muscle called spinchters which prevent the outflow of contents of a hollow organ. Contraction and relaxation of the smooth muscle in the walls of vessels help adjust blood vessel diameter and thus regulate the rate of blood flow. Smooth muscle contractions also move food and other things through GI tract. Skeletal muscle contractions promote the flow of lymph and aid the return of blood in veins to the heart. Generating heat: As muscular tissue contracts, it produces heat, a process known as thermogenesis. Much of the heat generated by muscle is used to maintain normal body temp. Involuntary contractions of skeletal muscles (shivering) can increase the rate of heat production.

Which statement best describes reciprocal innervation?

Relaxation of antagonist at the same time of contraction of agonist

Epicondyle

Roughened project

Describe the structures and functions of the cerebellum

Second only to the cerebrum in size, occupies the inferior and posterior aspects of the cranial cavity. Has a highly folded surface that greatly increases the SA of its outer gray matter cortex which allows for more neurons. Account for about a 1/10 of the brain mass and contains about half of the neurons in the brain. Resembles a butterfly. The central area is the vermis and the lateral wings/lobes are the cerebellar hemispheres. Each hemisphere consists of lobes separated by deep and distinct fissures. The anterior and posterior lobes govern subconscious aspects of skeletal muscle movements. The flocculonodular lobe of the inferior surface contributes to equillibrium and balance. Smooths and coordinates contractions of skeletal muscle. Regulates posture and balance. May have role in cognition and language processing. *** Prime function is to 'fine tune' motor function

The nervous system can distinguish between a light touch and a heavier touch because the frequency of impulses sent:

Sensory centers is changing

Compare the structural and functional differences between the somatic and autonomic nervous systems.

Sensory input: Somatic--> From somatic senses and special senses. Autonomic --> mainly from interoceptors; some from somatic senses and special senses. Control of Motor Output: Somatic--> Voluntary control from cerebral cortex, with contributions from basal ganglia, cerebellum, brainstem, and spinal cord. Autonomic-->Involuntary control from hypothalamus, limbic system, brainstem, and spinal cord; limited control from cerebral cortex. Motor Neuron Pathway: Somatic-->One-neuron pathway: Somatic motor neurons extending from CNS synapse directly with effector. Autonomic-->Usually two-neuron pathway: Preganglionic neurons extending from CNS synapse with postganglionic neurons in autonomic ganglion, and postganglionic neurons extending from ganglion synapse with visceral effector. Alternatively, preganglionic neurons may extend from CNS to synapse with chromaffin cells of adrenal medullae. Neurotransmitters and hormones: Somatic-->All somatic motor neurons release only acetylcholine (ACh). Autonomic-->All sympathetic and parasympathetic preganglionic neurons release ACh. Most sympathetic postganglionic neurons release NE; those to most sweat glands release ACh. All parasympathetic postganglionic neurons release ACh. Chromaffin cells of adrenal medullae release epinephrine and norepinephrine (NE). Effectors: Somatic--> Skeletal muscle Autonomic-->Smooth muscle, cardiac muscle, and glands. Responses: Somatic--> Contraction of skeletal muscles Autonomic--> Contraction or relaxation of smooth muscle; increased or decreased rate and force of contraction of cardiac muscle; increased or decreased secretions of glands.

Describe the functional components of a reflex arc

Sensory receptor: The distal end of a sensory neuron or an associated sensory structure serves as a sensory receptor. It responds to a specific stimulus--a change in the internal or external environment--by producing a graded potential called a generator potential. If a generator potential reaches the threshold level of depolarization, it will trigger one or more nerve impulses in the sensory neuron. Sensory neuron: The nerve impulses propagate from the sensory receptor along the axon of the sensory neuron to the axon terminals, which are located in the gray matter of the spinal cord or brainstem. From here, relay neurons send nerve impulses to the area of the brain that allows conscious awareness that the reflex has occurred. ** Involves the posterior root ganglion Integrating center: One or more regions of gray matter within the CNS acts as an integrating center. In the simplest type of reflex, the integrating center is a single synapse between a sensory neuron and a motor neuron. A reflex pathway having only one synapse in the CNS is a monosynaptic reflex. More often, the integrating center consists of one or more interneurons, which may relay impulses to other interneurons as well as to a motor neuron. A polysynaptic reflex arc involves more than two types of neurons and more than one CNS synapse. Motor neuron: Impulses triggered by the integrating center propagate out of the CNS along a motor neuron to the part of the body that will respond. Effector: The part of the body that responds to the motor nerve impulse, such as a muscle or a gland, is the effector. Its action is called a reflex. If the effector is skeletal muscle, the reflex is a somatic reflex. If the effector is smooth muscle, cardiac muscle, or a gland, the reflex is an autonomic reflex.

Compare three main functional classifications of neurons

Sensory/afferent: or afferent neurons (AF-er-ent NOO-ronz; af- = toward; -ferrent = carried) either contain sensory receptors at their distal ends (dendrites) (see also Figure 12.10) or are located just after sensory receptors that are separate cells. Once an appropriate stimulus activates a sensory receptor, the sensory neuron forms an action potential in its axon and the action potential is conveyed into the CNS through cranial or spinal nerves. Most sensory neurons are unipolar in structure. motor/efferent: or efferent neurons (EF-e-rent; ef- = away from) convey action potentials away from the CNS to effectors (muscles and glands) in the periphery (PNS) through cranial or spinal nerves (see also Figure 12.10). Motor neurons are multipolar in structure. inter/association: or association neurons are mainly located within the CNS between sensory and motor neurons (see also Figure 12.10). Interneurons integrate (process) incoming sensory information from sensory neurons and then elicit a motor response by activating the appropriate motor neurons. Most interneurons are multipolar in structure.

Describe three main functions of the nervous system

Sensory: Sensory receptors detect internal stimuli, such as an increase in blood pressure, or external stimuli (for example, a raindrop landing on your arm). This sensory information is then carried into the brain and spinal cord through cranial and spinal nerves. Motor: Once sensory information is integrated, the nervous system may elicit an appropriate motor response by activating effectors (muscles and glands) through cranial and spinal nerves. Stimulation of the effectors causes muscles to contract and glands to secrete. Integrative: The nervous system processes sensory information by analyzing it and making decisions for appropriate responses—an activity known as integration.

Spinous process

Sharp and slender projection

Identify the major joints of the body by location, classification, and movements

Shoulder joint: A ball and socket joint formed by the head of the humerus and the glenoid cavity of the scapula. Shoulder joints allow flexion, extension, hyperextension, abduction, adduction, medial rotation, lateral rotation, and circumduction of the arm. It has more freedom of movement than any other joint of the body. This is due to the looseness of the articular capsule and the shallowness of the glenoid cavity in relation to the large size of the heard of the humerus. The rotator cuff muscles work as a group to hold the head of the humerus in the glenoid cavity. Elbow joint: A hinge joint formed by the trochlea and capitulum of the humerus, the trochlear notch of the ulna, and the head of the radius. The elbow joint allows flexion and extension of the forearm. Hip joint: A ball and socket joint formed by the head of the femur and the acetabulum of the hip bone. It allows flexion, extension, abduction, adduction, lateral rotation, medial rotation, and circumduction of the thigh. It has a very strong articular capsule and accessory ligaments which is why it is so stable. However, the stability also limits ROM. Flexion is limited by anterior surface of the thigh coming into contact with the anterior abdominal wall when the knee is flexed and by tension of the hamstring muscles when the knee is extended. Extension, abduction, and adduction are also limited as well as medial and lateral rotation. Knee joint: The largest and most complex joint of the body. A modified hinge joint that consists of three joints within a single synovial cavity. The knee joint allows flexion, extension, slight medial rotation, and lateral rotation of the leg in the flexed position.

Describe the location, structure, and function of each type of epithelium found in the human body

Simple squamous epithelium is a single layer of flat cells that resembles a tiled floor when viewed from apical surface; centrally located nucleus that is flattened and oval or spherical in shape. Location: Most commonly (1) lines the cardiovascular and lymphatic system (heart, blood vessels, lymphatic vessels), where it is known as endothelium (en′‐dō‐THĒ‐lē‐um; endo‐ = within; ‐thelium = covering), and (2) forms the epithelial layer of serous membranes (peritoneum, pleura, pericardium), where it is called mesothelium (mez′‐ō‐THĒ‐lē‐um; meso‐ = middle). Also found in air sacs of lungs, glomerular (Bowman's) capsule of kidneys, inner surface of tympanic membrane (eardrum). Function: Present at sites of filtration (such as blood filtration in kidneys) or diffusion (such as diffusion of oxygen into blood vessels of lungs) and at site of secretion in serous membranes. Not found in body areas subject to mechanical stress (wear and tear). Simple cuboidal epithelium is a single layer of cube‐shaped cells; round, centrally located nucleus. Cuboidal cell shape is obvious when tissue is sectioned and viewed from the side. (Note: Strictly cuboidal cells could not form small tubes; these cuboidal cells are more pie‐shaped but still nearly as high as they are wide at the base.) Location: Covers surface of ovary; lines anterior surface of capsule of lens of the eye; forms pigmented epithelium at posterior surface of retina of the eye; lines kidney tubules and smaller ducts of many glands; makes up secreting portion of some glands such as thyroid gland and ducts of some glands such as pancreas. Function: Secretion and absorption. Nonciliated simple columnar epithelium is a single layer of nonciliated columnlike cells with oval nuclei near base of cells; contains (1) columnar epithelial cells with microvilli at apical surface and (2) goblet cells. Microvilli, fingerlike cytoplasmic projections, increase surface area of plasma membrane (see Figure 3.1), thus increasing cell's rate of absorption. Goblet cells are modified columnar epithelial cells that secrete mucus, a slightly sticky fluid, at their apical surfaces. Before release, mucus accumulates in upper portion of cell, causing it to bulge and making the whole cell resemble a goblet or wine glass. Location: Lines gastrointestinal tract (from stomach to anus), ducts of many glands, and gallbladder. Function: Secretion and absorption; larger columnar cells contain more organelles and thus are capable of higher level of secretion and absorption than are cuboidal cells. Secreted mucus lubricates linings of digestive, respiratory, and reproductive tracts, and most of urinary tract; helps prevent destruction of stomach lining by acidic gastric juice secreted by stomach. Ciliated simple columnar epithelium is a single layer of ciliated column like cells with oval nuclei near base of cells. Goblet cells are usually interspersed. Location: Lines some bronchioles (small tubes) of respiratory tract, uterine (fallopian) tubes, uterus, some paranasal sinuses, central canal of spinal cord, and ventricles of brain. Function: Cilia beat in unison, moving mucus and foreign particles toward throat, where they can be coughed up and swallowed or spit out. Coughing and sneezing speed up movement of cilia and mucus. Cilia also help move oocytes expelled from ovaries through uterine (fallopian) tubes into uterus. Nonciliated pseudostratified columnar epithelium appears to have several layers because the nuclei of the cells are at various levels. Even though all the cells are attached to the basement membrane in a single layer, some cells do not extend to the apical surface. When viewed from the side, these features give the false impression of a multilayered tissue—thus the name pseudostratified epithelium (pseudo‐ = false). Contains cells without cilia and also lacks globlet cells. Location: Lines epididymis, larger ducts of many glands, and parts of male urethra. Function: Absorption and secretion. Ciliated pseudostratified columnar epithelium appears to have several layers because cell nuclei are at various levels. All cells are attached to basement membrane in a single layer, but some cells do not extend to apical surface. When viewed from side, these features give false impression of a multilayered tissue (thus the name pseudostratified; pseudo = false). Contains cells that extend to surface and secrete mucus (globlet cells) or bear cilia. Location: Lines airways of most of upper respiratory tract. Function: Secretes mucus that traps foreign particles, and cilia sweep away mucus for elimination from body. Stratified squamous epithelium has two or more layers of cells; cells in apical layer and several layers deep to it are squamous; cells in deeper layers vary from cuboidal to columnar. As basal cells divide, daughter cells arising from cell divisions push upward toward apical layer. As they move toward surface and away from blood supply in underlying connective tissue, they become dehydrated and less metabolically active. Tough proteins predominate as cytoplasm is reduced, and cells become tough, hard structures that eventually die. At apical layer, after dead cells lose cell junctions they are sloughed off, but they are replaced continuously as new cells emerge from basal cells. Keratinized stratified squamous epithelium develops tough layer of keratin in apical layer of cells and several layers deep to it (see Figure 5.3). (Keratin is a tough, fibrous intracellular protein that helps protect skin and underlying tissues from heat, microbes, and chemicals.) Relative amount of keratin increases in cells as they move away from nutritive blood supply and organelles die. Nonkeratinized stratified squamous epithelium does not contain large amounts of keratin in apical layer and several layers deep and is constantly moistened by mucus from salivary and mucous glands; organelles are not replaced. Location: Keratinized variety forms superficial layer of skin; nonkeratinized variety lines wet surfaces (lining of mouth, esophagus, part of epiglottis, part of pharynx, and vagina) and covers tongue. Function: Protection against abrasion, water loss, ultraviolet radiation, and foreign invasion. Both types form first line of defense against microbes. Stratified cuboidal epithelium has two or more layers of cells; cells in apical layer are cube‐shaped; fairly rare type. Location: Ducts of adult sweat glands and esophageal glands, part of male urethra. Function: Protection; limited secretion and absorption. Basal layers in stratified columnar epithelium usually consist of shortened, irregularly shaped cells; only apical layer has columnar cells; uncommon. Location: Lines part of urethra; large excretory ducts of some glands, such as esophageal glands; small areas in anal mucous membrane; part of conjunctiva of eye. Function: Protection and secretion. Transitional epithelium (urothelium) has a variable appearance (transitional). In relaxed or unstretched state, looks like stratified cuboidal epithelium, except apical layer cells tend to be large and rounded. As tissue is stretched, cells become flatter, giving the appearance of stratified squamous epithelium. Multiple layers and elasticity make it ideal for lining hollow structures (urinary bladder) subject to expansion from within. Location: Lines urinary bladder and portions of ureters and urethra. Function: Allows urinary organs to stretch and maintain protective lining while holding variable amounts of fluid without rupturing. Endocrine gland secretions (hormones) enter interstitial fluid and then diffuse into bloodstream without flowing through a duct. Endocrine glands will be described in detail in Chapter 18. Location: Examples include pituitary gland at base of brain, pineal gland in brain, thyroid and parathyroid glands near larynx (voice box), adrenal glands superior to kidneys, pancreas near stomach, ovaries in pelvic cavity, testes in scrotum, thymus in thoracic cavity. Function: Hormones regulate many metabolic and physiological activities to maintain homeostasis. Exocrine gland secretory products are released into ducts that empty onto surface of a covering and lining epithelium, such as skin surface or lumen of hollow organ. Location: Sweat, oil, and earwax glands of skin; digestive glands such as salivary glands (secrete into mouth cavity) and pancreas (secretes into small intestine). Function: Produce substances such as sweat to help lower body temperature, oil, earwax, saliva, or digestive enzymes.

The rhomboid major is named for what characteristics?

Size and shape

Describe the types of fascicle arrangement in skeletal muscles + relate the arrangement to strength of contraction and range of motion.

Skeletal muscle fibers within a muscle are arranged in bundles known as fascicles. Within a fascicle, all muscle fibers are parallel to one another. However, they may form one of five patterns with respect to the tendons: Parallel: Fascicles parallel to longitudinal axis of muscle; terminate at either end in flat tendons. Ex: sternohyoid muscle Fusiform: Fascicles nearly parallel to longitudinal axis of muscle; terminate in flat tendons; muscle tapers toward tendons, where diameter is less than at belly. Ex: digastric muscle Circular: Fascicles in concentric circular arrangements from sphincter muscles that enclose an orifice. Ex: orbicularis oculi muscle Triangular: Fascicles spread over broad area converge at thick central tendon; gives muscle a triangular appearance. Ex: pectoralis major muscle Pennate: Short fascicles in relation to total muscle length; tendon extends nearly entire length of muscle Unipennate: Fascicles arranged on only one side of tendon. Ex: extensor digitorum longus muscle. Bipennate: Fascicles arranged on both sides of centrally positioned tendons. Ex: rectus femoris muscle Multipennate: Fascicles attach obliquely from many directions to several tendons. Ex: deltoid muscle

Why will an individual who lifts weights build larger muscles?

Skeletal muscles increase number of myofibrils but not number of cells

Contrast the three types of muscular tissue in terms of location, function, appearance, and control.

Skeletal: Most skeletal muscles move the bones of the skeleton. It is striated and works in a voluntary matter. It is controlled by neurons of the somatic (voluntary) nervous system. Cardiac: Forms most of the heart wall. It is also striated but involuntary. Autorhythmicity keeps the heart beating, while several neurotransmitters and electrolytes affect the rhythm. Smooth: Located in the walls of hollow internal structures, such as blood vessels, airways, and most organs in the abdominopelvic region. It is also found in the skin, attached to hair follicles. It lacks striations and is usually involuntary (some muscles, such as those that move food through the digestive tract has some autorhytmacity to them). Like cardiac muscle, it is regulated by neurons that are part of the autonomic nervous system. Smooth muscle fibers contain thin and thick filaments, as well as intermediate filaments, but none of them are arranged in sarcomeres.

Facet

Slightly concave or convex articulation surface

Compare the three main types of muscle fibers based on their size, mitochondria, capacity for generating ATP + method used, fatigue resistance, glycogen stores, order of recruitment, primary functions

Slow oxidative fibers (Type I): Appear dark red because they contain a lot of myoglobin and many blood capillaries. They have many large mitochondria so they generate ATP mainly by aerobic respiration. They are said to be slow because the ATPase in the myosin heads hydrolyzes ATP relatively slow, and the contraction cycle proceeds at a slower pace than in fast fibers. They have a slow speed of contraction. Their twitch contractions last from 100-200 msec and they take longer to reach peak tension. Slow fibers are very resistant to fatigue and are capable of prolonged sustained contractions for many hours. Adapted for maintaining posture and for aerobic, endurance-type activities. Fast oxidative-glycolytic fibers (Type IIa): Typically the largest fibers. they contain large amounts of myoglobin and many blood capillaries. They have a dark red appearance. They can also generate considerable ATP by aerobic respiration, which gives them a moderately high resistance to fatigue. Intracellular glycogen levelis high, they also generate ATP by anaerobic glycolysis. They are considered to be fast fibers because the ATPase in their myosin heads hydrolyzes ATP 3-5 x faster than the myosin ATPase is SO fibers. FOG fibers reach peak tension more quickly than SO fibers, but are briefer in duration (less than 100 msec). Contributes to activities like walking and sprinting. Fast glycolytic (Type IIx): These fibers have low myoglobin content and relatively few blood capillaries and few mitochondria. As a result, they appear white in color. They contain large amounts of glycogen and generate ATP mainly by glycolysis. Due to their ability to hydrolyze ATP rapidly, FG fibers contract strongly and quickly. They are fast twitch fibers that are adapted for intense anaerobic movements of short duration like weight lifting or throwing a ball. they fatigue quickly. The FG fibers of a weight lifter may be 50% larger than those of a sedentary or an endurance athlete because of increased synthesis of muscle proteins. The overall result is muscle enlargement due to hypertrophy of the FG fibers.

Describe common membrane proteins and their function

Some integral proteins form ion channels, pores or holes that specific ions, such as potassium ions (K+), can flow through to get into or out of the cell. Most ion channels are selective; they allow only a single type of ion to pass through. Other integral proteins act as carriers, selectively moving a polar substance or ion from one side of the membrane to the other. Carriers are also known as transporters. Integral proteins called receptors serve as cellular recognition sites. Each type of receptor recognizes and binds a specific type of molecule. For instance, insulin receptors bind the hormone insulin. A specific molecule that binds to a receptor is called a ligand (Lī-gand; liga = tied) of that receptor. Some integral proteins are enzymes that catalyze specific chemical reactions at the inside or outside surface of the cell. Integral proteins may also serve as linkers that anchor proteins in the plasma membranes of neighboring cells to one another or to protein filaments inside and outside the cell. Peripheral proteins also serve as enzymes and linkers. Membrane glycoproteins and glycolipids often serve as cell-identity markers. They may enable a cell to (1) recognize other cells of the same kind during tissue formation or (2) recognize and respond to potentially dangerous foreign cells. The ABO blood type markers are one example of cell-identity markers. When you receive a blood transfusion, the blood type must be compatible with your own, or red blood cells may clump together.

Describe spatial and temporal summation

Spatial: summation of postsynaptic potentials in response to stimuli that occur at different locations in the membrane of a postsynaptic cell at the same time. Ex: spatial summation results from the build up of neurotransmitter released simultaneously by several presynaptic end bulbs. Temporal: summation of postsynaptic potentials in response to stimuli that occur at the same location in the membrane of postsynaptic cell but at different times. Ex: temporal summation results from build up of neurotransmitter released by a single presynaptic end two or more times in rapid succession.

Describe the basis for mapping the primary somatosensory and motor areas

Specific areas of the cerebral cortex receive somatic sensory input from particular parts of the body. Other areas of the cerebral cortex provide output in the form of instructions for movement of particular parts of the body. The somatic sensory map and the somatic motor map relate body parts to these cortical areas. Precise localization of somatic sensations occurs when nerve impulses arrive at the primary somatosensory area, which occupies the postcentral gyri of the parietal lobes of the cerebral cortex. Each region in this area receives sensory input from a different part of the body. The left cerebral hemisphere has a similar primary somatosensory area that receives sensory input from the right side of the body.

Identify the number and location of spinal nerve pairs

Spinal nerves are the paths of communication between the spinal cord and specific regions of the body. The spinal cord appears to be segmented because the 31 pairs of spinal nerves emerge at regular intervals from intervertebral foramina. Each pair of spinal nerves is said to arise from a spinal segment. Within the spinal cord there is no obvious segmentation but the naming of spinal nerves is based on the segment in which they are located. There are 8 pairs of cervical nerves, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. 31 pairs: C1-C8, T1-T12, L1-L5, S1-S5, Co1

Define sensation and describe the process of sensation

Stimulation of sensory receptor: An appropriate stimulus must occur within the sensory receptor's receptive field, that is, the body region where stimulation activates the receptor and produces a response. *** The awareness of differences in the external or internal environment. Transduction of stimulus: A sensory receptor converts the energy in the stimulus into a graded potential, a process known as transduction. Recall that graded potentials vary in amplitude (size), depending on the strength of the stimulus that causes them, and are not propagated. Each type of sensory receptor exhibits selectivity: It can transduce (convert) only one kind of stimulus. For example, odorant molecules in the air stimulate olfactory (smell) receptors in the nose, which transduce the molecules' chemical energy into electrical energy in the form of a graded potential. Generation of nerve impulses: When a graded potential in a sensory neuron reaches threshold, it triggers one or more nerve impulses, which then propagate toward the CNS. Sensory neurons that conduct impulses from the PNS into the CNS are called first order neurons Integration of sensory input: A particular region of the CNS receives and integrates (processes) the sensory nerve impulses. Conscious sensations or perceptions are integrated in the cerebral cortex. You seem to see with your eyes, hear with your ears, and feel pain in an injured part of your body because sensory impulses from each part of the body arrive in a specific region of the cerebral cortex, which interprets the sensation as coming from the stimulated sensory receptors.

Describe six factors that influence the type of movement and ROM possible at a synovial joint

Structure of bones: Determines how closely the bones can fit together. The articular surfaces of some bones have a complementary relationship. This spatial relationship is very obvious at the hip joint, where the head of the femur articulates with the acetabulum of the hip bone. An interlocking fit allows for rotational movement. Strength of ligaments: The different components of fibrous capsule are tense or taut only when the joint is in certain positions. They direct the movement of the articulating bones with respect to each other. Arrangement of muscles: Muscle tension reinforces the restraint placed on a joint by its ligaments and therefore restricts movement. This can be seen in the hip joint when the thigh is flexed. Contact of soft parts: The point at which one body surface contacts another may limit mobility. An example is when you bend your arm at the elbow, it can move no farther after the anterior surface of the forearm meets with and presses against the biceps brachii muscle of the arm. Joint movement could also be restricted due to adipose tissue. Hormones: Joint flexibility can be affected by hormones. Relaxin for example, increases the flexibility of the fibrocartilage of the pubic symphysis and loosens the ligaments between the sacrum, hip bone, and coccyx toward the end of pregnancy. Disuse: Movement at a joint may be restricted if a joint has not been used for a long period of time. For example, an elbow in a cast ROM may be limited for a time after the cast is removed. This can also be a result of decreased synovial fluid, diminished flexibility of ligaments and tendons, and muscular atrophy.

Describe the six main functions of the skeletal system

Support: supports soft tissues and provides attachment points for the tendons of most skeletal muscles. Protection: Protects the most important internal organs from injury. Assistance in movement: most skeletal muscles attach to bone so that when they contract, they pull on the bones to produce movement. Mineral homeostasis (storage and release): bone tissue makes up about 18% of the weight. It stores calcium and phosphorus which contribute to bone strength. On demand, bone releases minerals into the blood to maintain critical mineral balances (homeostasis) and to distribute the minerals to other parts of the body. Blood cell production: Within certain bones, a connective tissue called red bone marrow produces RBCs, WBCs, and platelets by a process called hemopoiesis. Red bone marrow consists of developing blood cells, adipocytes, fibroblasts, and macrophages within a network of reticular fibers. It is present in developing bones of the fetus and some adult bones (like the hip, ribs, sternum etc) With age, much of the bone marrow changes from red to yellow. Triglyceride storage: yellow bone marrow with mostly adipose cells that store triglycerides. The stored triglycerides are considered to be a potential chemical energy reserve.

Identify the muscles that form the rotator cuff

Supraspinatus: A rounded muscle named for its location in the supraspinous fossa of the scapula, lies deep to the trapezius. Infraspinatus: A triangular muscle named for its location in the supraspinous fossa of the scapula, lies deep to the trapezius. Teres minor: A cylindrical, elongated muscle, often inseparable from the infraspinatus, which lies along its superior border. Subscapularis: A large triangular muscle that fills the subscapular fossa of the scapula and forms a small part in the apex of the posterior wall of the axilla.

Describe the structure and functions of the three types of cartilaginous joints.

Synchondroses: A joint in which the connecting material is hyaline cartilage and is slightly movable to immovable. An example of this type of joint is the first rib and manubrium of the sternum. Symphyses: A join tin which the ends of the articulating bones are covered with hyaline cartilage. A broad flat disc of fibrocartilage connects the bone. All symphyses occurs in the mid line of the body; the pubic symphysis is an example of a symphysis. Other examples include the junction of the manubrium and body of sternum and at the intevertebral joints between the bodies of vertebrae. A symphysis is a slightly movable joint. Epiphyseal growth plates: hyaline cartilage growth centers during endochondral bone formation, not joints associated with movements. An example of this is the epiphyseal growth plate that connects the epiphysis and diaphysis of a growing bone. Functionally, it is an immovable joint. When bone elongation ceases, bone replaces the hyaline cartilage and becomes a bony joint.

Recall the number, name, type, and major functions of each cranial nerve

Table 14.4 and class slides Olfactory I: To smell. -Sensory nerve -Sense of smell -Olfactory cells converge to become olfactory nerve -Damage to the olfactory pathway may result in loss of smell -Receptors are on the superior nasal conchae (upper bony plate; ethmoid bone) Optic II -Sensory nerve -Ganglion cells in the retina of the each eye join to form an optic nerve -Nerve of vision -Damage to the optic pathway can result in loss of vision -Rods=night vision -Cones= day & color vision Oculomotor III: -Motor cranial nerve -Originates in the mid brain -Supplies extrinsic eye muscles to control movements of the eye ball and upper eyelid. Trochlear IV: -Motor cranial nerve -Smallest of the 12 cranial nerves -Origin: midbrain -Controls movement of the eyeball -Innervates superior oblique muscle and acts to internally rotate the eye -Damage to the trochlear or oculomotor nerve can cause cross eye or double vision. Trigeminal V: -Largest cranial nerve -Mixed nerve -Three branches: opthalmic, maxillary, and mandibular -Deals with sensation of touch, pain, and temperature -Motor axons supply muscles of mastication Abducens VI: -Motor cranial nerve -Originates from the pons -Causes abduction of the eye ball ( lateral rotation) Facial VII: -Mixed cranial nerve -Sensory potion extends from the taste buds of the anterior two-thirds of the tongue -Motor portion arises from the pons and deals with facial expression -Damage to the motor portion of the nerve can cause facial paralysis, or Bell's palsy Vestibulocochlear VIII: -Sensory cranial nerve -Originates in the inner ear -Vestibular branch caries impulses for equilibrium -Cochlear branch carries impulses for hearing -Damage to the vestibular branch can cause vertigo, a feeling that a person is rotating -Damage to the cochlear branch can cause tinnitus or deafness Glossopharyngeal IX: -Mixed cranial nerve -Sensory axons carry signals from the taste buds of the posterior one third of the tongue -Motor neurons arise from the medulla and deal with the release of saliva Vagus X: -Mixed cranial nerve -Sensory neurons deal with a variety of sensations such as proprioception and stretching -Motor neurons arise from the medulla and supply muscles of the pharynx, larynx, and soft palate -Parasympathetic axons supply glands of the GI tract and smooth muscle of the respiratory passageways and digestive organs Accessory XI: -Motor cranial nerve -Historically was divided into cranial accessory and spinal accessory nerves -Cranial accessory is actually part of vagus -Supplies sternocleidomastoid and trapezius muscles to coordinate head movements -Damage to this nerve could result in the person having difficulty turning their head or raising their shoulders Hypoglossal XII: -Motor cranial nerve -Conducts nerve impulses for speech and swallowing -Damage to this nerve would result in difficulty swallowing ** Cranial nerves are part of the PNS

Describe the location and function of somatic sensory receptors for tactile, thermal, and pain sensations

Tactile: include touch, pressure, vibration, itch, and tickle. Although we perceive differences among these sensations, they arise by activation of some of the same types of receptors. Several types of encapsulated mechanoreceptors attached to large-diameter myelinated A fibers mediate sensations of touch, pressure, and vibration. Other tactile sensations, such as itch and tickle sensations, are detected by free nerve endings attached to small-diameter, unmyelinated C fibers. Recall that larger-diameter, myelinated axons propagate nerve impulses more rapidly than do smaller-diameter, unmyelinated axons. Tactile receptors in the skin or subcutaneous layer include corpuscles of touch, hair root plexuses, type I cutaneous mechanoreceptors, type II cutaneous mechanoreceptors, lamellated corpuscles, and free nerve endings Thermal: are free nerve endings that have receptive fields about 1 mm in diameter on the skin surface. Two distinct thermal sensations—coldness and warmth—are detected by different receptors. Cold receptors are located in the stratum basale of the epidermis and are attached to medium-diameter, myelinated A fibers, although a few connect to small-diameter, unmyelinated C fibers. Temperatures between 10° and 35°C (50 − 95°F) activate cold receptors. Warm receptors, which are not as abundant as cold receptors, are located in the dermis and are attached to small-diameter, unmyelinated C fibers; they are activated by temperatures between 30° and 45°C (86 − 113°F). Cold and warm receptors both adapt rapidly at the onset of a stimulus, but as noted earlier in the chapter they continue to generate impulses at a lower frequency throughout a prolonged stimulus. Temperatures below 10°C and above 45°C primarily stimulate pain receptors, rather than thermoreceptors, producing painful sensations, which we discuss next. Pain: Pain is indispensable for survival. It serves a protective function by signaling the presence of noxious, tissue-damaging conditions. From a medical standpoint, the subjective description and indication of the location of pain may help pinpoint the underlying cause of disease.

Recall how CSF is circulated through ventricles and spinal cord

The CSF formed in the choroid plexuses of each lateral ventricle flows into the third ventricle through two narrow, oval openings, the interventricular foramina. More CSF is added by the choroid plexus in the roof of the third ventricle. The fluid then flows through the aqueduct of the midbrain (cerebral aqueduct), which passes through the midbrain, into the fourth ventricle. The choroid plexus of the fourth ventricle contributes more fluid. CSF enters the subarachnoid space through three openings in the roof of the fourth ventricle: a single median aperture and paired lateral apertures, one on each side. CSF then circulates in the central canal of the spinal cord and in the subarachnoid space around the surface of the brain and spinal cord.

Identify the accessory structures of the eye

The accessory structures of the eye include the eyelids, eyelashes, eyebrows, the lacrimal (tear-producing) apparatus, and extrinsic eye muscles.

Identify the major parts of the brain

The adult brain consists of four major parts: brainstem, cerebellum, diencephalon, and cerebrum. The brainstem is continuous with the spinal cord and consists of medulla oblongata, pons, and the mibrain. Cerebrum: Supported on the diencephalon and brain stem is the cerebrum - the largest part of the brain. Diencephalon: Superior to the brainstem. It consists of the thalamus, hypothalamus, and epithalamus. Brain stem: Continuous with the spinal cord and consists of the medulla oblongata, pons, and midbrain. Cerebellum: Posterior to the brain stem. It monitors actual movement, provides movement corrections, monitors intentions for movement, and receives input from the vestibular apparatus in the inner ear. It DOES NOT initiate movement

Identify the components of the eye and describe their functions

The adult eyeball measures about 2.5 cm (1 in.) in diameter. Of its total surface area, only the anterior one-sixth is exposed; the remainder is recessed and protected by the orbit, into which it fits. Anatomically, the wall of the eyeball consists of three layers: (1) fibrous tunic: Cornea: Admits and refracts (bends) light. Sclera: Provides shape and protects inner parts. (2) vascular tunic: Iris: Regulates amount of light that enters eyeball.Ciliary body: Secretes aqueous humor and alters shape of lens for near or far vision (accommodation).Choroid: Provides blood supply and absorbs scattered light. (3) retina (inner tunic): Receives light and converts it into receptor potentials and nerve impulses. Output to brain via axons of ganglion cells, which form optic (II) nerve.

Describe the clinical significance of dermatomes

The area of the skin that provides sensory input to the CNS via one pair of spinal nerves or the trigeminal (V) nerve is called a dermatome. The nerve supply in adjacent dermatomes overlaps somewhat. Knowing which spinal cord segments supply each dermatome makes it possible to locate damaged regions of the spinal cord. If the skin in a particular region is stimulated but the sensation is not perceived, the nerves supplying that dermatome are probably damaged. In regions where the overlap is considerable, little loss of sensation may result if only one of the nerves supplying the dermatome is damaged. Information about the innervation patterns of spinal nerves can also be used therapeutically. Cutting posterior roots or infusing local anesthetics can block pain either permanently or transiently. Because dermatomes overlap, deliberate production of a region of complete anesthesia may require that at least three adjacent spinal nerves be cut or blocked by an anesthetic drug.

Define origin and insertion as it relates to skeletal muscles

The attachment of a muscle's tendon to the stationary bone is called the origin; the attachment of the muscle's other tendon to a movable bone is called the insertion.

Explain how the processing of visual signals in the retina and the neural pathway for vision

The axons of the retinal ganglion cells form the optic (II) nerve which provide output from the retina to the brain. The optic (II) nerves pass through the optic chiasm, a crossing point of the optic nerves. Some axons cross to the opposite side, but others remain uncrossed. After passing through the optic chiasm, the axons, now part of the optic tract, enter the brain and most of them terminate in the lateral geniculate nucleus of the thalamus. Here they synapse with neurons whose axons form the optic radiations, which project to the primary visual areas in the occipital lobes of the cerebral cortex, and visual perception begins. Some of the fibers in the optic tracts terminate in the superior colliculi, which control the extrinsic eye muscles, and the pretectal nuclei, which control pupillary and accommodation reflexes.

Describe the process involved in bone remodeling.

The bone is continually renewing itself. Bone remodeling is considered the ongoing replacement of old bone tissue by new bone tissue. It involves bone resorption, the removal of minerals and collagen fibers from bone by osteoclasts, and bone deposition, the addition of minerals and collagen fibers to bone by osteoblasts. Thus, bone resorption results in the destruction of bone extracellular matrix, while bone deposition results in the formation of bone extracellular matrix. Remodeling also removes injured bone, replacing it with new bone tissue. Remodeling may be triggered by factors such as exercise, sedentary lifestyle, and changes in diet. During the process of bone resorption, an osteoclast attaches tightly to the bone surface at the endosteum or periosteum and forms a leakproof seal at the edges of its ruffled border Then it releases protein‐digesting lysosomal enzymes and several acids into the sealed pocket. The enzymes digest collagen fibers and other organic substances while the acids dissolve the bone minerals. Working together, several osteoclasts carve out a small tunnel in the old bone. The degraded bone proteins and extracellular matrix minerals, mainly calcium and phosphorus, enter an osteoclast by endocytosis, cross the cell in vesicles, and undergo exocytosis on the side opposite the ruffled border. Now in the interstitial fluid, the products of bone resorption diffuse into nearby blood capillaries. Once a small area of bone has been resorbed, osteoclasts depart and osteoblasts move in to rebuild the bone in that area.

Explain the concept of selective permeability

The lipid bilayer portion of the plasma membrane is highly permeable to non-polar molecules such as oxygen (O2), carbon dioxide (CO2), and steroids Moderately permeable to small, uncharged polar molecules, such as water and urea (a waste product from the breakdown of amino acids). Impermeable to ions and large, uncharged polar molecules, such as glucose. The permeability characteristics of the plasma membrane are due to the fact that the lipid bilayer has a nonpolar, hydrophobic interior. So, the more hydrophobic or lipid-soluble a substance, the greater the membrane's permeability to that substance. Thus, the hydrophobic interior of the plasma membrane allows nonpolar molecules to rapidly pass through, but prevents passage of ions and large, uncharged polar molecules. The permeability of the lipid bilayer to water and urea is an unexpected property given that they are polar molecules. These two molecules are thought to pass through the lipid bilayer in the following way: As the fatty acid tails of membrane phospholipids and glycolipids randomly move about, small gaps briefly appear in the hydrophobic environment of the membrane's interior. Because water and urea are small polar molecules that have no overall charge, they can move from one gap to another until they have crossed the membrane. Transmembrane proteins that act as channels and carriers increase the plasma membrane's permeability to a variety of ions and uncharged polar molecules that, unlike water and urea molecules, cannot cross the lipid bilayer unassisted. Channels and carriers are very selective. Each one helps a specific molecule or ion to cross the membrane. Macromolecules, such as proteins, are so large that they are unable to pass across the plasma membrane except by endocytosis and exocytosis (discussed later in this chapter).

Recall the lobes of the cerebrum

The lobes are named after the bones that cover them. occipital parietal frontal temporal insula

Outline the auditory pathway to the brain

The release of neurotransmitter from hair cells of the spiral organ ultimately generates action potentials in the first-order auditory neurons that innervate the hair cells. The axons of these neurons form the cochlear branch of the vestibulocochlear (VIII) nerve. These axons synapse with neurons in the cochlear nuclei in the medulla oblongata. Some of the axons from the cochlear nuclei decussate (cross over) in the medulla, ascend in a tract called the lateral lemniscus on the opposite side, and terminate in the inferior colliculus of the midbrain. Other axons from the cochlear nuclei end in the superior olivary nucleus of the pons. Slight differences in the timing of action potentials arriving from the two ears at the superior olivary nuclei allow us to locate the source of a sound. Axons from the superior olivary nuclei ascend to the midbrain, where they terminate in the inferior colliculi. From each inferior colliculus, axons extend to the medical geniculate nucleus of the thalamus. Neurons in the thalamus, in turn, project axons to the primary auditory area of the cerebral cortex in the temporal lobe of the cerebrum in the temporal lobe, where conscious awareness of sound occurs. From the primary auditory cortex, axons extend to the auditory association area of the cerebral cortex in the temporal lobe of the cerebrum for more complex integration of sound input. The arrival of action potentials in the primary auditory area allows you to perceive sound. One aspect of sound that is perceived by this area is pitch (frequency). The primary auditory area is mapped according to pitch: Input about pitch from each portion of the basilar membrane is conveyed to a different part of the primary auditory area. High frequency sounds activate one part of the auditory area, low-frequency sounds activate another part, and medium-frequency sounds activate the region in between. Hence, different cortical neurons respond to different pitches. Neurons in the primary auditory area also allow you to perceive other aspects of sound such as loudness and duration. From the primary auditory area, auditory information is conveyed to the auditory association area in the temporal lobe. This area stores auditory memories and compares present and past auditory experiences, allowing you to recognize a particular sound as speech, music, or noise. If the sound is speech, input in the auditory association is relayed to Wernicke's area in the adjacent part of the temporal lobe, which interprets the meaning of words, translating them into thoughts.

Explain the functional advantage of myelination of neurons

The sheath electrically insulates the axon of a neuron and increases the speed of nerve impulse conduction. The amount of myelin increases from birth to maturity, and its presence greatly increases the speed of nerve impulse conduction. An infant's responses to stimuli are neither as rapid nor as coordinated as those of an older child or an adult, in part because myelination is still in progress during infancy.

Describe how the skeleton is organized into axial and appendicular divisions.

There are 80 bones of the axial skeleton (8 cranium bones, 14 facial bones, 6 auditory ossicles, 26 vertebral column, 1 sternum bone, and 24 rib bones) and 126 bones of the appendicular skeleton (2 clavicles, 2 scapula, 2 humerus, 2 ulna, 2 radius, 16 carpals, 10 metacarpals, 28 phalanges, 2 hip/pelvic, 2 femurs, 2 patella, 2 fibula, 2 tibia, 14 tarsals, 10 metatarsals, and 28 phalanges) bones of the upper and lower limbs plus the bones forming the girdle that connect the limbs to the axial skeleton.

Distinguish thick filaments from thin filaments.

Thin filaments are 8nm in diameter and 1-2 um long and composed mostly of actin while thick filaments are 16 nm in diameter and 1-2 um long and composed of myosin. Both are directly involved in the contractile process. Overall, there are two thin filaments for every thick filament in the regions of filament overlap. The filaments inside a myofibril do not extend the entire length of a muscle fiber. Instead, they are arranged in compartments called sarcomeres.

Describe the length-tension relationship in skeletal muscles (see Figure 10.8)

This relationship indicates how the forcefulness of muscle contraction depends on the length of the sarcomeres within a muscle before contraction begins. When the sarcomere is at a length of about 2.0-2.4 uM, the zone of overlap in each sarcomere is optimal so that the muscle fiber can develop max tension. Max tensions occurs when the zone of overlap between a thick and thin filaments extends from the edge of the H zone to one end of a thick filament.

Outline the gustatory pathway to the brain

Three cranial nerves contain axons of the first-order gustatory neurons that innervate the taste buds. The facial (VII) nerve serves taste buds in the anterior two-thirds of the tongue; the glossopharyngeal (IX) nerve serves taste buds in the posterior one-third of the tongue; and the vagus (X) nerve serves taste buds in the throat and epiglottis. From the taste buds, nerve impulses propagate along these cranial nerves to the gustatory nucleus in the medulla oblongata. From the medulla, some axons carrying taste signals project to the limbic system and the hypothalamus; others project to the thalamus. Taste signals that project from the thalamus to the primary gustatory area in the insula of the cerebral cortex give rise to the conscious perception of taste and discrimination of taste sensations.

Recall major spinal nerves of the sacral plexus

Tibial: L4-S3 gastrocnemius, plantaris, soleus, popliteus, tibialias posterior, flexor digitorum longus, and flexor hallucis longus muscles. Branches of tibial nerve in foot are medial plantar nerve and lateral plantar nerve. Common fibular nerve: L4-S2 divides into superficial fibular and deep fibular branch.

Meatus

Tube-like passageway

Recall the structure, distribution, and functions of hair, skin glands, and nails

Types of hair: lanugo: Usually by the fifth month of development, the follicles produce very fine, non-pigmented, downy hairs called lanugo that cover the body of the fetus. vellus: The lanugo of the rest of the body are replaced by vellus hairs, commonly called "peach fuzz," which are short, fine, pale hairs that are barely visible to the naked eye. During childhood, vellus hairs cover most of the body except for the hairs of the eyebrows, eyelashes, and scalp, which are terminal hairs. In response to hormones (androgens) secreted at puberty, terminal hairs replace vellus hairs in the axillae (armpits) and pubic regions of boys and girls and they replace vellus hairs on the face, limbs, and chests of boys, which leads to the formation of a mustache, a beard, hairy arms and legs, and a hairy chest. During adulthood, about 95% of body hair on males is terminal hair and 5% is vellus hair; on females, about 35% of body hair is terminal hair and 65% is vellus hair. terminal: Prior to birth, the lanugo of the eyebrows, eyelashes, and scalp are shed and replaced by long, coarse, heavily pigmented hairs called terminal hairs. Types of glands: sebaceous: are simple, branched acinar (rounded) glands. With few exceptions, they are connected to hair follicles. The secreting portion of a sebaceous gland lies in the dermis and usually opens into the neck of a hair follicle. In some locations, such as the lips, glans penis, labia minora, and tarsal glands of the eyelids, sebaceous glands open directly onto the surface of the skin. Absent in the palms and soles, sebaceous glands are small in most areas of the trunk and limbs, but large in the skin of the breasts, face, neck, and superior chest. sudoriferous: There are three million to four million sudoriferous glands or sweat glands in the body. The cells of these glands release sweat, or perspiration, into hair follicles or onto the skin surface through pores. Sweat glands are divided into two main types, eccrine and apocrine, based on their structure and type of secretion. ceruminous: Modified sweat glands in the external ear, called ceruminous glands, produce a waxy lubricating secretion. The secretory portions of ceruminous glands lie in the subcutaneous layer, deep to sebaceous glands. Their excretory ducts open either directly onto the surface of the external auditory canal (ear canal) or into ducts of sebaceous glands. The combined secretion of the ceruminous and sebaceous glands is a yellowish material called cerumen, or earwax. Cerumen, together with hairs in the external auditory canal, provides a sticky barrier that impedes the entrance of foreign bodies and insects. Cerumen also waterproofs the canal and prevents bacteria and fungi from entering cells.

Describe the factors that maintain a resting membrane potential

Unequal distribution of ions: in the ECF and cytosol. A major factor that contributes to the resting membrane potential is the unequal distribution of various ions in extracellular fluid and cytosol. Extracellular fluid is rich in Na+ and chloride ions (Cl−). In cytosol, however, the main cation is K+, and the two dominant anions are phosphates attached to molecules, such as the three phosphates in ATP, and amino acids in proteins. Because the plasma membrane typically has more K+ leak channels than Na+ leak channels, the number of potassium ions that diffuse down their concentration gradient out of the cell into the ECF is greater than the number of sodium ions that diffuse down their concentration gradient from the ECF into the cell. As more and more positive potassium ions exit, the inside of the membrane becomes increasingly negative, and the outside of the membrane becomes increasingly positive. Inability of most anions to leave the cell: Another factor contributes to the negative resting membrane potential: Most anions inside the cell are not free to leave. They cannot follow the K+ out of the cell because they are attached to nondiffusible molecules such as ATP and large proteins. Electrogenic nature of Na-K ATPase: Membrane permeability to Na+ is very low because there are only a few sodium leak channels. Nevertheless, sodium ions do slowly diffuse inward, down their concentration gradient. Left unchecked, such inward leakage of Na+ would eventually destroy the resting membrane potential. The small inward Na+ leak and outward K+ leak are offset by the Na+-K+ ATPases (sodium-potassium pumps). These pumps help maintain the resting membrane potential by pumping out Na+ as fast as it leaks in. At the same time, the Na+-K+ ATPases bring in K+. However, the potassium ions eventually leak back out of the cell as they move down their concentration gradient. Recall that the Na+-K+ ATPases expel three Na+ for each two K+ imported. Since these pumps remove more positive charges from the cell than they bring into the cell, they are electrogenic, which means they contribute to the negativity of the resting membrane potential. Their total contribution, however, is very small: only −3 mV of the total −70 mV resting membrane potential in a typical neuron. *** a resting nerve fiber is polarized because the concentration of Na + is higher on the outside and K+ is higher on the inside

Tuberosity

Variably sized projecting that is rough

Tubercle

Variably sized rounded projection

Describe the protective structures and gross anatomical features of the spinal cord

Vertebral column: The first later of protection for the CNS. The spinal cord is located within the vertebral canal of the vertebral column. The surrounding vertebrae provide a sturdy shelter for the enclosed spinal cord. Meninges: The second protective layer of the spinal cord. Composed of three membranes that lie between the bony encasement and the nervous tissue in both the brain and spinal cord. Three protective, connective tissue coverings that encircle the spinal cord and brain. From superficial to deep they are the (1) dura mater, (2) arachnoid mater, and (3) pia mater. The spinal meninges surround the spinal cord and are continuous with the cranial meninges, which encircle the brain. All three spinal meninges cover the spinal nerves up to the point where they exit the spinal column through the intervertebral foramina. Dura mater: The most superficial of the three spinal meninges is a thick strong layer composed of dense irregular connective tissue. The dura mater forms a sac from the level of the foramen magnum in the occipital bone, where it is continuous with the meningeal dura mater of the brain, to the second sacral vertebra. The dura mater is also continuous with the epineurium, the outer covering of spinal and cranial nerves. Arachnoid mater: This layer, the middle of the meningeal membranes, is a thin, avascular covering comprised of cells and thin, loosely arranged collagen and elastic fibers. It is called the arachnoid mater because of its spider's web arrangement of delicate collagen fibers and some elastic fibers. It is deep to the dura mater and is continuous through the foramen magnum with the arachnoid mater of the brain. Between the dura mater and the arachnoid mater is a thin subdural space, which contains interstitial fluid. Pia mater: This innermost meninx is a thin transparent connective tissue layer that adheres to the surface of the spinal cord and brain. It consists of thin squamous to cuboidal cells within interlacing bundles of collagen fibers and some fine elastic fibers. Within the pia mater are many blood vessels that supply oxygen and nutrients to the spinal cord. Triangular-shaped membranous extensions of the pia mater suspend the spinal cord in the middle of its dural sheath. These extensions, called denticulate ligaments, are thickenings of the pia mater. They project laterally and fuse with the arachnoid mater and inner surface of the dura mater between the anterior and posterior nerve roots of spinal nerves on either side. Subarachnoid space: Between the arachnoid mater and pia mater is a space, the subarachnoid space, which contains shock-absorbing cerebrospinal fluid. Conus medullaris: Inferior to the lumbar enlargement, the spinal cord terminates as a tapering, conical structure. The spinal cord ends between the first and second lumbar vertebrae. Denticulate ligaments: These extensions are thickenings of the pia mater. They project laterally and fuse with the arachnoid mater and inner surface of the dura mater between the anterior and posterior nerve roots of spinal nerves on either side. Conus medullaris: Inferior to the lumbar enlargement, the spinal cord terminates as a tapering, conical structure. Cauda equina: The roots of these lower spinal nerves angle inferiorly alongside the filum terminale in the vertebral canal like wisps of hair.

Describe how frequency of stimulation affects muscle tension. (see Figure 10.14)

When a second stimulus occurs after the refractory period of the first stimulus is over, but before the skeletal muscle fiber has relaxed, the second contraction will actually be stronger than the first. This phenomenon is called wave summation. When a skeletal muscle fiber is stimulated at a rate of 20-20 times per sec, it can only partially relax between stimuli. the result is a sustained by wavering contraction called unfused tetanus. When it is stimulated at an even higher rate, it is not able to relax at all. The result is fused tetanus.

Example of levers & fulcrum

When biting into an apple, the temporomandibular joint is the fulcrum and acts like a third class lever because the food is in the front of the mouth. When chewing the apple, the mandible acts like a second class lever because the food is in the middle of the lever arm.

Identify the regions and normal curves of the vertebral column.

When looking at the adult vertebral column from the side, you can see four slight bends called normal curves. Relative to the front of the body, the cervical and lumbar curves are convex (bulging out); the thoracic and sacral curves are concave (cupping in). The curves of the vertebral column increase its strength, help maintain balance in the upright position, absorb shocks during walking, and help protect the vertebrae from fracture. Various conditions may exaggerate the normal curves of the vertebral column, or the column may acquire a lateral bend, resulting in abnormal curves of the vertebral column. Three such abnormal curves—kyphosis, lordosis, and scoliosis ****** The two primary curves of the adult vertebral column are the thoracic and sacral curves.

Distinguish between gray and white matter

White Matter: Composed primarily of myelinated axons. The whitish color of myelin gives white matter its name. Gray Matter: Contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia. It appears grayish due to the nissl bodies where there is little to no myelin in these areas. Blood vessels are present in both white and gray matter. In the spinal cord, the white matter surrounds an inner core of gray matter. A thin shell of gray matter covers the surface of the largest portions of the brain, the cerebrum and the cerebellum.

Define prime mover, antagonist, synergist, and fixator as to how they work together in a muscle group to produce movement.

Within opposing pairs, one muscle called the prime mover or agonist contracts to cause an action while the other muscle, the antagonist stretches and yields to the effects of the prime mover. In the process of flexing the forearm at the elbow, the biceps brachii is the prime mover and the triceps brachii is the antagonist. The anatgonist and prime mover are usually located on opposite sides of the bone or joint. To prevent unwanted movements at intermediate joints or to otherwise aid the movement of the prime mover, muscles called synergists contract and stabilize the intermediate joints. Some muscles in a group also act as fixators--they stabilize the origin of the prime mover so that the prime mover can act more efficiently. Fixators steady the proximal end of a limb while movements occur at the distal end.

Distinguish bands + zones within a sarcomere

Z disc: Narrow, plate shaped regions of dense protein material that separate one sarcomere from the next. A band: The darker middle part of the sarcomere. it extends the entire length of thick filaments. Toward each end of the A band is a zone of overlap, where the thick and thin filaments lie side by side. ********* The light A bands remain at a constant length. I band: A lighter less dense area that contains the rest of the thin filaments but no thick filaments. H zone: A narrow H zone in the center of each A band contains thick but not thin filaments. M line: Supporting proteins that hold the thick filaments together at the center of the H zone form the M line -- it is named because it is at the middle of the sarcomere.

Plasticity means the ability to

change based on experience

Describe an electrochemical gradient

concentration gradient and electrical gradient are important because they help move substances across the plasma membrane. In many cases a substance will move across a plasma membrane down its concentration gradient. That is to say, a substance will move "downhill," from where it is more concentrated to where it is less concentrated, to reach equilibrium. Similarly, a positively charged substance will tend to move toward a negatively charged area, and a negatively charged substance will tend to move toward a positively charged area. The combined influence of the concentration gradient and the electrical gradient on movement of a particular ion is referred to as its electrochemical gradient.

Define homeostasis

is the maintenance of relatively stable conditions in the body's internal environment. It occurs because of the ceaseless interplay of the body's many regulatory systems. Homeostasis is a dynamic condition. In response to changing conditions, the body's parameters can shift among points in a narrow range that is compatible with maintaining life.