A & P

Describe the dermatomes of the nipple, umbilicus, hand, and foot.

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Functional areas of the 5 cerebral lobes

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What structures are involved in the auditory pathway?

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How are neurons classified functionally?

1) According to travel direction Sensory neurons= afferent, carry impulses from the sensory receptors to the CNS, always in ganglion outside CNS, keep us informed about in/outside, have receptors on dendrite endings (5 senses) Receptors= in skin, cutaneous sense organs (if strong can also be pain) Stretch and tension= in muscles and tendons= proprioceptors = "one's own" advise brain of our own movement Pain receptors= most #, bare nerve endings, least specialized In CNS: Motor or efferent neurons= neurons carrying impulses from CNS to viscera, muscles, and glands, Motor (efferent) neurons= carry impulses away from CNS to viscera, muscles, glands Interneurons= (association neurons)= found in neural pathways in the CNS, connect sensory and motor neurons in neural pathways (holding urine) 2) Structural Classification based on the # of processes from cell body Multipolar neuron= many processes extending from cell body, all motor and association neurons, most common structural type Bipolar neurons= neurons with two processes: axon and dendrite, rare, only found in special sensory organs, sensory processing. Unipolar neurons= single process, sensory neurons in in PNS ganglia, cell body, divides, proximal, distal processes CNS, only small branches at end of PNS processes are dendrites, axon conducts nerve impulses both to and from cell body

Functions of cranial nerves. Describe in detail.

12 pairs, primarily serve head and neck, 1 pair extends to abdominal and thoracic cavities (vagus), numbered in order, names reveal most important structures they control, most cranial nerves are mixed nerves, 3 pairs are sensory: optic, olfactory, vestibulochlear-(acoustic nerve) "oh oh oh to touch and feel very good velvet ah" 1. Olfactory= olfactory receptors in nasal mucosa synapse with olfactory bulbs which sends fibers to olfactory cortex. 2. Optic= retina of eye, form optic nerve, 2 optic nerves form optic (sensory) chiasma, crossover by partial- fibers go to optic cortex as optic tracts 3. Oculomotor= runs from midbrain to eye (motor) Supplies motor fibers to 4 of the 6 muscles that direct the eyeball: superior, inferior, medial rectus, inferior oblique. Controls eyelid, internal eye muscles, pupil, lens shape 4. Trochlear= From midbrain to eye: motor fibers for one eye muscle= superior oblique 5. Trigeminal= fibers emerge from pons- form 3 divisions: run to face. Conducts sensory impulses from skin of face and mucosa of nose and mouth. Motor fibers that activate chewing muscles 6. Abducens= fibers leave pons and run into the eye, supplies motor fibers to lateral rectus muscle, rolls eye laterally 7. Facial= fibers leave pons and run to face. Activates muscles of facial expression and lacrimal and salivary glands, carries sensory impulses from taste buds of anterior tongue. 8. Vestibulocochlear= from equilibrium and hearing receptors of inner ear to brain stem, transmits impulses for balance, cochlear transmits impulse for hearing 9. Glossopharyngeal= emerge from medulla and run to throat, supplies motor fibers to pharynx that promote swallowing, saliva, carries impulses for taste buds of posterior tongue and from pressure receptors of carotid artery (gag) 10. Vagus= Emerge medulla, descend into thorax and abdominal cavity, carry sensory impulses from motor impulses to, pharynx, larynx, abdominal, thoracic, viscera. Most motor fibers are para-sympathetic fibers- promote digestive activity, help regulate heart activity. 11. Accessory= from superior spinal cord C1-C5, travel to muscles of neck and back. Motor fibers that activate the sternocleidomastoidus and trapezius 12. Hypoglossal= from medulla to tongue, control tongue movements, sensory fibers carry impulses from the tongue

What are the examples of stimuli for hormone release?

3 Major Categories of Endocrine Gland Stimuli: *most, not all 1. Hormonal Stimuli= hypothalamus, hormone to hormone, gland to gland, most common, endocrine organs prodded into action by other hormones, is rythmic- with blood levels rising and falling continuously 2. Humoral Stimuli= anterior pituitary gland, 'various body fluids'- changing blood levels of certain ions and nutrients stimulate hormone release (decreasing blood calcium levels prompt release of parathyroid hormone by cells of parathyroid glands. blood calcium levels rise, end parathyroid stimulus. Other hormones released in response to humoral stimuli= calcitonin, insulin) 3. Neural Stimuli= thyroid or adrenal gland, nerve fibers stimulate hormone release, the target cells respond to 'neural stimuli (adrenal release norepinephrine, sympathetic system)

How many pairs of spinal and cranial nerves?

31 Spinal, 12 cranial

What cranial nerves control the extrinsic muscles that move the eyeball?

Abducens VI= lateral rectus, moves eye laterally Oculomotor III= medial rectus, moves eye medially Oculomotor III= superior rectus, elevates eye and turns it medially Oculomotor III= inferior rectus, depresses eye and turns it medially Oculomotor III= inferior oblique, elevates eye and turns it laterally Trochlear IV= superior oblique, depresses eye and turns it laterally

What are the functions of the hormones secreted by the adrenal cortex? Describe adrenal cortex disorders.

Adrenal Glands= two, bean shaped, curve over top of kidneys, two endocrine organs in one: *Glandular cortex= (like pituitary) *Medulla= neural tissue *Central Medulla= enclosed by adrenal cortex= contains 3 cell layers: Adrenal Cortex *Produces three major groups of steroid hormones= corticosteroids: Outermost Layer 1. Mineralocorticoids= aldosterone= produced by outermost cell layer, regulates mineral content (salt) of blood - (sodium potassium pump) *target= kidney tubules that selectively reabsorb minerals or allow them to be flushed out of the body in urine. *Blood aldosterone levels rise= kidney tubules reclaim sodium, secrete potassium. When sodium is reabsorbed, water is as well *Regulates water and electrolyte balance in body fluids *Aldosterone release stimulated by humoral factors -fewer sodium ions or more potassium ions in blood Renin= an enzyme produced by kidneys when blood pressure drops. Triggers angiotensin II = a stimulator of aldosterone release Atrial natriuratic peptide (ANP)= prevents aldosterone release, goal= reduce blood volume and blood pressure Middle Cortical Layer Glucocorticoids= cortisone and cortisol *Promote normal cell metabolism, help body resist long term stressors, increase blood glucose levels, high levels break down fats and proteins by body cells- converted to glucose which is released in the blood (hyperglycemic hormones) *Control inflammation by decreasing edema *Reduce pain, inhibit prostaglandins-(pain producing molecules) *Released from adrenal cortex in response to rising blood levels of ACTH *Adrenal cortex produces male and female sex hormones in small amounts *Androgens= the bulk of sex hormones, produced by innermost cortex layer *Estrogens= also formed Diseases: Addison's disease= general hyposecretion of all adrenal cortex hormones, bronze skin, low aldosterone= electrolyte imbalance, no sodium and water Hypoglycemia= deficient glucocorticoids= low stress coping, infection Hypoaldersteronism= ACTH retaining tumor, retain sodium and water, lose potassium, heart, nervous system Cushing's Syndrome= moon face, excess gas, buffalo hump, high blood pressure, weak bones Hyper sex= masculinization- beard, body hair Adrenal Medulla Layer *Secretes 2 hormones= Catecholamines *Develops from knot of nervous tissue (like posterior pituitary) *Stimulated by sympathetic nervous system neurons to release two similar hormones: 1. Epinephrine= adrenaline 2. Norepinephrine= noradrenaline *Catecholamines, pumps hormones into blood by sympathetic system "fight or flight" *Increases heart rate, blood pressure, blood glucose, dilates lungs *More oxygen, supplied faster, better able to deal with stress or be alert *Alarm stage of stress response Glucocorticoids help with long term stress and resistance stage of stress response.

How are hormones classified chemically?

Amino acid based molecules (biggest): Proteins Peptides- small protein Amines- amino acids Steroids (lipids) - made from cholesterol, sex hormones made by gonads, hormones produced by adrenal cortex Prostaglandins- not a steroid or cholesterol lipid, a phospholipid, made from highly active lipids released from nearly all cell membranes, more localized - (inflammation, fever, anti inflammatory= anti prostaglandins.)

What are the major effects of the autonomic nervous system?

Autonomic is the motor subdivision of PNS, controls body activities automatically, specialized group of neurons regulate cardiac muscle, smooth muscle in walls of visceral organs and glands, big contributor to homeostasis, makes adjustments to signals that come to CNS from visceral organs, Also called involuntary nervous system). body organs served by autonomic receive fibers from both sympathetic and parasympathetic (except blood vessels, skin structures, some glands and the adrenal medulla- only sympathetic fibers received)

What is the function of the cerebral (basal) nuclei?

Basal nuclei= "islands" of gray matter- basal ganglia, regulate voluntary motor activities by modifying instructions stop=start sent to skeletal muscles by primary motor cortex (problems with basal nuclei = Parkinsons and Huntington can't walk normally) Internal capsule= tight band of projection fibers, passes between thalamus and basal nuclei

Flexion and Extension of Elbow

Biceps brachii- bulges when elbow is flexed, originates by two heads of shoulder girdle. Insert: radial tuberosity (prime mover for forearm, flexion, supinates forearm, flex elbow ie. pulling a cork out of a bottle of wine) Triceps brachii- only muscle fleshing out posterior humerus, 3 heads arise: shoulder girdle, and proximal humerus Insert: olecranon process ulna (elbow extension prime mover, antagonist of biceps brachii, "boxer muscle" O

What is the relationship among renin, angiotensin, and aldosterone?

Blood aldosterone levels rise= kidney tubules reclaim sodium, secrete potassium. When sodium is reabsorbed, water is as well *Regulates water and electrolyte balance in body fluids *Aldosterone release stimulated by humoral factors -fewer sodium ions or more potassium ions in blood Renin= an enzyme produced by kidneys when blood pressure drops. Triggers angiotensin II = a stimulator of aldosterone release Atrial natriuratic peptide (ANP)= prevents aldosterone release, goal= reduce blood volume and blood pressure

How do calcitonin and parathyroid hormone regulate the blood calcium levels?

Calcitonin *Decreased blood calcium levels by causing calcium to be deposited in bones *Antagonist to parathyroid hormone *Made by parafollicular cells= in connective tissue between the follicles that make thyroxine *Released directly to the blood in response to high calcium levels. *Low levels in adults, no known disorders Parathyroid glands= tiny masses of glandular tissue on posterior surface of thyroid Two on each lobe=total of 4, could be 8= distributed in other regions of neck and thorax as well Secrete parathyroid hormone Parathyroid Hormone (PTH) *Parahormone= the most important regulator of calcium ion (Ca2+) homeostasis of blood *Blood calcium drops= PTH released by parathyroids= stimulates bone destruction cells (osteoclasts) to break down bone matrix and release calcium into the blood= hypercalcemic Parathyroid Hormone is hypercalcemic (more calcium), Calcitonin is hypocalcemic (less calcium) *Targets skeleton and kidneys

What ion is required for muscle contraction?

Calcium (Ca2+) triggers binding of myosin to actin which initiates filaments sliding. After action potential ends Ca2+ is reabsorbed into sarcoplasmic reticulum for storage

What structures detect the sense of smell and taste?

Chemoreceptors= receptors for taste and olfaction, respond to chemicals in solution, 5 types of taste receptors, thousands of olfactory receptors. Complement each other, respond to same stimuli Smell Olfactory receptors= 1,000's, smell, in root of nasal cavity, postage stamp sized patch, receptor cells= neurons with olfactory hairs-long cilia- protrude from nasal epithelium, bathed in mucus, transmit impulses along olfactory filaments Olfactory filaments= bundled axons of olfactory neurons, make up olfactory nerve (cranial nerve) Olfactory nerve= conducts impulses to olfactory cortex of brain, odor is interpreted "odor snapshot" Olfactory pathways have close ties to limbic system (emotional, visceral emotions, memories, and smell Taste Taste buds= 10,000, scattered on surface of tongue, soft palate, superior pharynx, inner surface of cheeks Papillae= covers dorsal tongue, small, peg like projections Circumvallate papillae= large, round, have taste buds on sides Fungiform papillae= numerous, have taste buds on top Gustatory cells= specific cells that respond to chemicals dissolved in saliva- epithelial cells Gustatory hairs= long microvilli on gustatory cells, protrude through the taste pore, depolarize when stimulated, transmit impulses to brain. 3 Cranial Nerves carry impulses from taste buds to the gustatory cortex: Facial Nerve VII- anterior part of tongue Glossopharyngeal IX Vagus X Taste buds= replaced by basal cells every 7-10 days Sweet receptors= tip of tongue, respond to sugar, saccharine, some amino acids, lead salts Sour receptors= side of tongue, respond to hydrogen ions (H+), or acidity Bitter receptors= rear of tongue, respond to alkaloids Salty receptors= respond to metal ions in solutions Umami= "delicious", elicited by glutamate, beef flavor of steak Most taste buds respond to two, three, four, or five taste modalities, taste likes and dislikes satisfy homeostasis

What structure connects 2 cerebral hemispheres?

Corpus callosum= long, fiber tract, connects cerebral hemispheres, arches above structures of brain, allows communication of cerebral hemispheres with each other. Association fiber tracts- connect areas within hemisphere Projection fiber tracts- connect cerebrum with lower CNS structures Basal nuclei= "islands" of gray matter- basal ganglia, regulate voluntary motor activities by modifying instructions stop=start sent to skeletal muscles by primary motor cortex (problems with basal nuclei = Parkinsons and Huntington)

Describe the structure and function of the spinal cord.

Cylindrical, 17 inches (42 cm) long, continuation of brainstem, a 2 way conduction pathway to and from brain, major reflex center, extends from foramen magnum of skull to 1st or 2nd lumbar vertebrae, ends just below the ribs, cushioned and protected by meninges (meningal coverings extend past spinal cord in vertebral canal) can be removed past L3 for testing 31 pairs of nerves arise from cord, exit vertebral column, size of a thumb, larger in cervical and lumbar areas-(nerves of upper and lower limbs) Cauda Equina= spinal column nerves that must travel through vertebral canal- looks like a tail, at inferior end of vertebral column Gray Matter of Spinal Cord and Spinal Roots Looks like a letter H or butterfly in cross section Dorsal or posterior horns= two posterior projections Ventral or anterior horns= two anterior projections Gray matter surrounds central canal of chord that contains cerebrospinal fluid Gray matter of spinal cord contains neurons Dorsal horns contain interneurons Dorsal root ganglion= enlarged area, cell bodies of sensory neurons- enter by dorsal root Ventral horns contain cell bodies of motor neurons of the somatic (voluntary) nervous system= send axons out of the ventral root of the cord Dorsal and Ventral roots fuse= spinal nerves damage to ventral root= flaccid paralysis White Matter of Spinal Cord Myelinated fiber tracts: across, up, down, brain to cord, lower, higher divided into 3 Regions: Contain fiber tracts of axons with the same destination and function 1) Dorsal= all tracts are ascending, sensory 2) Lateral= both ascending and descending, motor Ventral Columns= both ascending and descending, motor Sensory, afferent tracts= conduct sensory impulses to brain Motor, efferent tracts= carry impulses from brain to skeletal muscles

Abduction and Adduction Upper Arm

Deltoid- fleshy, triangle, forms shoulders, bulky, good injection site. Abducts arm Latissimus dorsi- 2 large, flat, cover lower back, origin:lower spine and ilium, sweeps superiorly to insert into proximal end of humerus. Extends and abducts humerus, like in swimming, bringing arms down.

Difference between somatic and autonomic nervous system

Different effector organs and neurotransmitters released, different pattern of motor pathways Somatic= cell bodies of motor neurons are inside CNS, their axons extend all the way to skeletal muscles Autonomic= has a chain of two motor neurons: 1. preganglionic in brain or spinal cord axons leaves CNS to synapse with 2. postganglionic neuron outside CNS, (postganglionic axon extends to organ it serves). 2 arms, both serve same organs, cause opposite effects: 1. Sympathetic and 2. Parasympathetic

Naming skeletal muscles:

Direction of limbs: rectus-straight oblique- at a slant to midline, imaginary line, or longitudinal axis Size of muscle: maximus- largest minimus- smallest longus- long Named according to bones: temporalis frontalis Number of origins: biceps- two origins triceps- three origins quadriceps- four origins Location of origin and insertion: sterno= sternum origin clavicle= "cleido" inserts on mastoid process of temporal bone (sternocleidomastoid) Shape: Deltoid- triangle Action: Flexor, extensor, adductor

2. Endomysium = delicate connective tissue sheath, encloses each muscle fiber

Endomysium = delicate connective tissue sheath, encloses each muscle fiber Perimysium = coarser fiber membrane, covers several sheathed fibers Fascicle = bundle of fibers, wrapped by perimysium Epimysium = binds many fascicles together, tough connective tissue overcoat Fascia epimysium = (on outside of epimysium) covers the entire muscle, blends into tendons or aponeuroses Tendons and aponeuroses attach muscles directly to bones, cartilages, and connective tissue coverings Tendons = tough, collagenic fibers (so they can cross bony projections), small, tough, more tendons than fleshy muscles can pass over a joint Sarcolemma= "muscle husk", plasma membrane of a muscle fiber, many nuclei Myofibril = long, ribbon-like organelles, push nuclei aside, nearly fill the cytoplasm, have light (I) and dark (A) bands, light and dark bands give muscle a striped look, myofibrils are aligned, the ability to contract depends on myofilaments. Sarcomeres=tiny contractile units, make up myofibrils, a chain, line up like a train along length of myofibrils (2 discs with distance between), myofilaments within sarcomeres create banding pattern, 2 types of myofilaments within sarcomeres: thick and thin. Thick filaments= "mysosin filaments", myosin protein and ATPase, enzymes split ATP to generate power for muscle contraction (for big movement), extend entire length of dark (A) band. Midpoints are smooth, ends are studded with projections called cross bridges Cross bridges= have "myosin heads", link thick and thin filaments during contraction Thin filaments= "actin filaments", contain actin, a contractile protein, regulating proteins that allow or prevent myosin heads from binding to actin Actin filaments= anchored to (z disc, a disc like membrane) H zone lacks actin filaments (Light I) or thin filaments do not overlap so it is bare in the middle (called the H zone) ( the strength of muscle depends on number of sarcomeres sliding) Sarcoplasmic reticulum= specialized, smooth endoplasmic reticulum, surrounds each myofibril like a crocheted sweater, role is to store calcium and release it on demand when muscle contracts Muscle fiber= a cylindrical, multinucleate cell composed of numerous myofibrils that contracts when stimulated

6. Properties of skeletal muscle cells:

Excitability or responsiveness = the ability to receive and respond to stimulus, Contractility = the ability to forcibly shorten when adequately stimulated, (skeletal muscles are stimulated to contract by neurons) Extensibility= ability of muscle cells to be stretched, Elasticity= ability to recoil and resume resting length after stretching

Different types of body movement

Flexion= sagittal plane, decreases angle of joint, brings 2 bones closer (hinge joints, knee, elbow, ball and socket, hip bends forward) Extension= opposite of flexion, increase angle or distance between two bones (straighten knee or elbow hyperextension = more than 180) Rotation= movement of bone around longitudinal axis (ball and socket, shaking head no, medial/lateral rotation=leg) Abduction= moving a limb on frontal plane away from midline or median (fanning fingers or toes) Adduction= movement of a limb towards midline Circumduction= proximal end is stationary, distal end moves in circle. Combination of flexion, extension, abduction, and abduction (ball and socket shoulder and hip) limb outlines a cone. Movements of tongue, mandible, and scapula= protraction, retraction, elevation, depression Special Movements: Dorsiflexion and plantar flexion= up and down of foot and ankle Dorsiflexion= lifting foot so superior surface approaches shin, hand extension towards wrist. Plantar flexion= pointing toes, flexion of hand Inversion= foot, turn sole medially Eversion= turn sole laterally Supination= "turning backward" forearm rotates laterally, palm is anterior, radius and ulna are parallel Pronation= "turning forward" forearm rotates medially, palm posterior, radius and ulna cross, form an x Opposition= saddle joint bewteen metacarpal 1 and carpals allow for opposition of thumb

How is a spinal nerve formed? What is the largest nerve in the body?

Formed by combination of ventral and dorsal roots of spinal cord. Sciatic is largest. After forming, spinal nerves immediately divide into dorsal and ventral rami (each spinal nerve is only 1/2 inch long) Rami= both sensory and motor fibers Smaller dorsal rami= skin, muscles of posterior body trunk Ventral rami= T1-T12, spinal nerves = intercostal nerves, supply muscles between ribs and skin + muscles of anterior and lateral trunk. Plexuses= ventral rami of spinal nerves that are not T1-T12= complex networks of nerves, serve sensory, motor needs of limbs 4 nerve plexuses ; Cervical C1-C5, Brachial C5-C8 T1, Ventral T1-T12 Lumbar L1-L4 , Sacral L4-L5, Si-S4

Flexion and Extension of hip

Gluteus maximus- superficial hip, forms buttock, hip extensor, brings thigh in straight line with pelvis, extends hip, not most important for walking (climbing stairs, jumping) Origin: sacrum and iliac Insertion: gluteal tuberosity of femur and into large tendinous iliotibial tract Gluteus medius- ilium to femur, beneath gluteus maximus, hip abductor, steadies pelvis when walking, injection site, 4 quadrants to avoid sciatic nerve, best site for injection is superolateral quadrant. Iliopsoas- fused, 2 muscles: ilacus and psoas major. Iliac bone and lower vertebrae deep inside pelvis. Insert: lesser trochanter of femur (Prime mover of hip flexion, keeps body from falling backward when standing) Adductor- medial side of each thigh, press thighs together. Origin: pelvis Insert: proximal end of femur

3 Common Injection sites

Gluteus medius in superolateral quadrant, Deltoid, Vastus lateralis and Rectus femoris (for infants)

Flexion and Extension of knee

Hamstring group= posterior thigh, 3: biceps femoris, semimembranous, and semitendinous. Origin: ischial tuberosity, run down thigh Insert: both sides of proximal tibia. (prime movers of thigh and knee extension, flexion) Sartorius= thin, straplike, most superficial, oblique across thigh from anterior iliac crest to medial side of tibia, weak thigh flexor, "tailor's muscle" = cross legged position Quadriceps group= 4 rectus femoris plus 3 vastus muscles that flesh out anterior thigh. (Vastus intermedius= hidden by rectus femoris) Vastus= originate in femur, Rectus femoris= originate on pelvis. All four insert into tibial tuberosity via patellar ligament. All act to extend knee for kicking. Rectus femoris can flex hip, crosses two joints of hip and knee. Vastus lateralis and Rectus femoris are used in infant injection sites.

Members of Quadriceps and Hamstrings

Hamstring group= posterior thigh, 3: biceps femoris, semimembranous, and semitendinous. Origin: ischial tuberosity, run down thigh Insert: both sides of proximal tibia. (prime movers of thigh and knee extension, flexion) Quadriceps group= 4 rectus femoris plus 3 vastus muscles that flesh out anterior thigh. (Vastus intermedius= hidden by rectus femoris) Vastus= originate in femur, Rectus femoris= originate on pelvis. All four insert into tibial tuberosity via patellar ligament. All act to extend knee for kicking. Rectus femoris can flex hip, crosses two joints of hip and knee. Vastus lateralis and Rectus femoris are used in infant injection sites.

What structures are responsible for hearing and balance?

Internal area of ear hearing and balance. Middle and external= hearing only. External 'outer' ear Auricle= (pinna)- 'ear', shell shaped, surrounds auditory canal External acoustic meatus= (auditory canal), short, narrow chamber, 1 inch by 1/4 inch wide, carved into temporal bone of skull Ceruminous glands= secrete earwax (cerumen) in walls of external meatus Tympanic membrane= (eardrum) where sound waves hit, vibrates auditory canal, ends at eardrum which separates middle from external. Middle Ear (Tympanic Cavity) Small, air filled, mucosa lined cavity within temporal bone Flanked laterally by eardrum, medially by oval window Oval window= bony wall with two openings Round window= inferior, membrane covered Pharyngotympanic tube= 'auditory tube', runs obliquely downward to link middle ear cavity with throat (stays closed unless you yawn-pressure) Middle Ear Bones: 3, ossicles- smallest bones in body, transmit vibrations of ear drum to fluids of inner ear 1. Hammer= malleus= moves with eardrum, transfers vibrations to anvil 2. Anvil= incus= passes vibrations on to stirrup 3. Stirrup= stapes= presses on oval window of inner ear, movement of oval window moves fluid, excites hearing receptors Hearing receptors= mechanoreceptors- receptors that respond to physical forces (sound vibrations, movements) Internal (Inner) Ear : Bony 'osseous' labyrinth= "maze", deep in temporal bone behind eye socket. 3 Subdivisions: 1. cochlea= spiraling, pea sized, snail 2. vestibule 3. semicircular canals perilymph= plasma like fluid that fills bony labyrinth membranous labyrinth= suspended in the perilymph, a system of membrane sacs, follows shape of bony labyrinth endolymph= thicker fluid inside the membranous labyrinth Equilibrium responds to various head movements Vestibular apparatus= inner ear equilibrium receptors, divided into two arms for static and dynamic equilibrium Static equilibrium Maculae= within membranous sacs of vestibule 'spots', report changes of head in space with respect to gravity, up and down one maculae= patch of receptor (hair cells) with their 'hairs' embedded in otolithic membrane- a jelly mass studded with otoliths otoliths= tiny stones made of calcium salts, roll in response to head movements, gravity changes. The gel pulls, bends hairs, activates hair cells, they send impulses to Vestibular nerve ( a division of cranial) to the cerebellum of brain to inform it of head position Dynamic Equilibrium Receptors in semicircular canals, respond to angular or rotary movement of head, 1/3 inch around, oriented in 3 planes of space Crista ampullaris= within ampulla-(swollen region at base of each membranous circular canal) Receptor region= tuft of hair cells, covered with cupula- a gelatinous cap Cupula bends, drags with body motion, stimulates hair cells- impulses are transmitted 'like a swinging door' Hearing Spiral Organ of Corti= within cochlear duct, contains endolymph, membranous labyrinth of cochlea, contains hearing receptors or hair cells, Scalae- chambers above and below the cochlear duct contain perilymph Cochlear fluids set in motion by: sound waves reaching cochlea through vibrations of eardrum, ossicles, and oval window Ossicles- increase amplitude of vibrations from eardrum to oval window by lever activity, pressure waves at oval window set vibrations onto: Basilar membrane= in Spiral Organ of Corti, hairs are bent by Tectorial membrane-gel lik, lies over them Basillar membrane fibers= tune regions to vibrate at specific frequencies Hairs transmit impulses to Cochlear nerve VIII (division of vestibulocochlear) to auditory cortex in temporal lobe

Isotonic vs. Isometric contraction

Isotonic = 'same tone" or "tension" myofilaments slide, the muscle shortens, movement occurs. (bending knee, rotate arms) Isometric = 'same measurement" myosin filaments are spinning their wheels and the muscle tension keeps increasing. Filaments are trying to slide but muscle is against an immovable object. (trying to lift a 400 lb. dresser, triceps contract isometrically)

How are tears formed and drained?

Lacrimal apparatus= lacrimal gland and a number of ducts that drain the lacrimal secretions into the nasal cavity. Lacrimal glands= located above lateral end of each eye, release a dilute solution (tears) onto anterior surface through ducts Tears= flush into lacrimal canaliculi medially across eyeball, then into lacrimal sac, and finally into nasolacrimal duct which empties into nasal cavity. Lysozyme= an enzyme that destroys bacteria, in lacrimal secretions, secretions contain: mucus, antibodies, lysozyme, cleans and protects as it moisturizes.

Structure responsible for controlling emotions

Limbic system

What does the brainstem consist of?

Midbrain, Pons, Medulla Oblongata

Rotator cuff muscles: Teres minor Infraspinatus Supraspinatus Subscapularis

Muscle Origin on scapula Attachment on humerus Function Innervation Supraspinatus muscle supraspinous fossa superior and middle facet of the greater tuberosity abducts the arm Suprascapular nerve (C5) Infraspinatus muscle infraspinous fossa posterior facet of the greater tuberosity externally rotates the arm Suprascapular nerve (C5-C6) Teres minor muscle middle half of lateral border inferior facet of the greater tuberosity externally rotates the arm Axillary nerve (C5) Subscapularis muscle subscapular fossa lesser tuberosity (60%) or humeral neck (40%) internally rotates the humerus Upper and Lower subscapular nerve (C5-C6)

What's wrong with myopia, hyperopia, presbyopia, astigmatism, cataract, and glaucoma?

Myopia= 'short vision' nearsighted, distant objects appear blurry. Parallel light rays from distant objects do not reach retina and are focused in front of it. Lens accommodation makes eyeball too long, they need concave lenses to see distant objects. Hyperobia= 'far vision' , parallel light rays from distant objects are focused behind the retina, short eye, lazy lens, need convex corrective lenses Presbyopia= elderly vision, need bifocals OOOO Astigmatism= unequal curvature of cornea and lens surface Cataract= cloudiness of lens, age, metabolic disease, diabetes, heredity Glaucoma= blocked aqueous humor, aqueous humor is reabsorbed into venous blood through scleral venous sinus or canal of Schlemm located at junction of sclera and cornea. Vision goes gray due to increased intraocular pressure, draining is good.

How is the nervous system ordered according to structure and function?

Nervous System= the master controlling and communicating system of the body. (Thought, action, emotion) Communicates via electrical impulses. Nervous + endocrine = homeostasis 3 Overlapping Functions: 1) Use sensory receptors to monitor changes occurring inside and outside. Changes= stimuli Information= sensory input 2) Process and interpret sensory input and decide what should be done. 3) Effects or causes a response by activating muscles or glands= effectors via motor output Structural Classification: 2 Subdivisions: Central Nervous System= brain, spinal cord, occupy dorsal cavity, the integrating and command centers of the nervous system Interprets information, issues instructions based on past experience and current conditions Peripheral Nervous System= outside CNS, nerves that extend from brain and spinal cord, link body, carry impulses from sensory receptors to CNS, CNS glands, and muscles Spinal nerves= carry impulses to and from spinal cord Cranial nerves= carry impulses to and from brain (the communication lines, link body by carrying impulses from sensory receptors to CNS, and from CNS to muscles and glands) 2 Subdivisions of PNS: 1) Sensory (afferent) division = nerves, composed of nerve fibers, convey impulses to CNS from sensory receptors in various parts of the body Afferent= "to go toward" Somatic= 'soma'- body 'sensory'- afferent fibers- sensory fibers delivering impulses from skin, skeletal muscles, joints. Visceral = afferents, sensory fibers= transmit impulses from visceral organs Sensory division keeps CNS constantly informed about input/output of body 2) Motor or efferent division= carries impulses from CNS to effector organs, muscles, and glands. Impulses activate muscles, glands, and effect a motor response. 2 Subdivisions of Motor Efferent Division: 1) Somatic nervous system= voluntary nervous system, allows conscious, voluntary, control (skeletal, some reflexes) 2) Autonomic Nervous System= involuntary, regulates events that are automatic or involuntary (smooth muscle, cardiac, glands) Autonomic: 2 subdivisions (bring aout opposite effects): Sympathetic= emergency situations, stressful, fight or flight Parasympathetic= rest and digest

Neurons vs. neuroglia

Neuroglia- support cells in CNS. Functions: support, insulate, protect neurons, 'nerve glue' or glia- glial cells. Never lose the ability to divide, resemble neurons but do not transmit impulses Types of Neuroglia: Astrocytes= support cells, abundant 1/2 of neural tissue, star shaped, numerous projections with swollen ends cling to neurons, brace, anchor, neurons to nutrient supply lines- the blood capillaries. brace neurons, form a living barrier between capillaries and neurons= blood, brain barrier. It controls the chemical environment of the brain. Help determine capillary permeability, making exchanges between the two, controls chemicals by 'mopping up' potassium ions, recaptures released neurotransmitters. Microglia= spider like phagocytes that monitor the health of nearby neurons, dispose of debris, dead brain cells, bacteria Ependymal cells= glial cells, lining central cavity of brain and spinal cord, cilia help circulate cerebrospinal fluid in cavity and protect CNS Oligodendrocytes= glia with flat extensions (processes) they wrap processes around nerve fibers tightly and produce fatty insulating coverings or myelin sheaths "scanty" produce nerve fibers (M.S. = demyelinating disease) Gliomas- tumor, since neuroglia always divide 2 Varieties of Supporting Cells in PNS: Satellite cells= act as protective cushioning cells protecting neuron bodies (PNS) Schwann cells= form myelin sheaths around nerve fibers in the peripheral nervous system Neurons= irritability, conductivity, resting are polarized (less + ions on inner face of plasma membrane than outer face) nerve cells, highly specialized to transmit messages. Differ structurally with common features: cell body, nucleus, processes Cell body= metabolic center, transparent nucleus, cytoplasm has organelles- lacks centrioles, no dividing= amitotic Has abundant Nissl bodies or neurofibrils that maintain cell shape. Nissl bodies= specialized rough endoplasmic reticulum Processes= arm like fibers, vary in length, (3-4 ft., lumbar to big toe) Dendrites= (100's) processes that convey incoming messages towards cell body Axons = (only 1) generate nerve impulses, conduct them away from cell body Axons hillcock= conelike regions of cell body where axons come from All axons branch alot at terminal end= axon terminals Axon terminal= contain vesicles with neurotransmitters, impulse from axon reaches axon terminal with sacs- they release the neurotransmitters when stimulated into extracellular space Synaptic cleft= separates axon terminals from next neuron synapse-'to clasp' join neurons- never touch Separated by synapse- junction between neurons Cleft- gap between adjacent neurons Myelin sheath= whitish, fatty material covering axon (nerve fibers), waxy, protect, insulate, increase transmission rate of nerve impulses Axons outside CNS= myelinated by Schwann cells= produce myelin sheath in rolls. Schwann cell cytoplasm is gradually squeezed from between membrane layers, after wrapping, a tight coil of membranes or myelin sheath encloses axon. Cytoplasm ends up beneath outer part of its plasma membrane= external myelin sheath or " neuron husk" Nodes of Ranvier= gaps in myelin sheath at regular intervals Ganglia= small collections of cell bodies outside CNS and PNS Nuclei= clusters of cell bodies within central nervous system Neuron processes= bundles of nerve fibers. (In CNS= tracts In PNS= nerves) White matter= collection of myelinated fibers, dense collection of tracts Gray matter= unmyelinated fibers and cell bodies, cortex, basal nuclei situated deep in white matter

Interrelationship among prime mover, antagonist, synergist

Opposite movements muscles lie on opposite sides of a joint Prime mover= muscle with the major responsibility for movement Antagonists= muscles that oppose or reverse a movement (can be prime movers) Prime movers are active, antagonists are relaxed and stretched Synergists= "syn" together" 'erg" work help prime movers by producing the same movement or by reducing undesirable movements (when muscle crosses 2 or more joints, all will move without synergist to stabilize them) Fixators= specialized synergists, hold a bone still or stabilize the origin of a prime mover so all the tension can be used to move the insertion bone. (postural muscles that stabilize vertebral column, anchors scapula to thorax)

Describe the structures involved in the visual pathway?

Optic nerve= bundles of axons carrying impulses from retina, back of eye Optic chiasma= 'cross' -fibers from medial side of each eye cross over to opposite sides of brain Optic tracts= fiber tracts, fibers from lateral side of eye on same side and the medial side of the opposite eye. synapse with neurons in the thalamus. Thalamus axons= optic radiation= runs to occipital lobe of the brain= synapse with cortical cells for visual interpretation Visual fields overlap. We have binocular 'two eyed' vision for depth perception Visual cortex fuses 2 images into one that can be deciphered

Difference between origin and insertion of a muscle

Origin= attached to immovable or less movable bone Insertion= attached to movable bone, insertion moves toward origin (some muscles have interchangeable origins/insertions ie. rectus temoris anterior thigh)

How do 2 pancreatic hormones regulate the blood glucose levels?

Pancreatic Islets- Islets of Langerhons *located close to stomach in abdominal cavity *In acinar tissue (enzyme producing) of pancreas *Enzyme producing part of pancreas= exocrine- digestive system *An organ within an organ, one million plus islets Hormones= Insulin and Glucagon plus others *Cells act as fuel sensors- secrete insulin and glucagon during fed and fasting state *Beta cells= release insulin when blood levels of glucose are high Insulin= acts on all body cells, lets glucose cross plasma membranes Glucose is then oxidized for energy inside cells, or made into fat *Hypoglycemic effect= Insulin= decreases blood glucose levels, sweeps glucose out of blood. Glucagon= Antagonist of Insulin *Released by alpha cells= stimulated by low blood glucose *Target= liver= stimulates it to break down stored glycogen to glucose and release it into blood.

What is the function of the auditory (Eustachian) tube?

Pharyngotympanic tube= 'auditory tube', runs obliquely downward to link middle ear cavity with throat (stays closed unless you yawn-pressure)

What muscles do phrenic, axillary, radial, musculocutaneous, median, ulnar, femoral, sciatic, common fibular, and tibial nerves innervate?

Phrenic= cervical plexus; diaphragm, skin and muscles of shoulder and neck Axillary= brachial plexus; deltoid, muscles and skin of shoulder, skin of superior thorax Radial= brachial= triceps, extension of forearm, skin of posterior upper limb Musculocutaneous= brachial; flexor muscles of arm, skin of lateral forearm Median= brachial; flexor muscles and skin of forearm, some muscles of hand Ulnar= brachial; some flexor muscles of forearm, wrist, hand muscles, skin of hand Femoral= lumbar; lower abdomen, anterior and medial thigh muscles, hip flexors, knee extensors, skin of anteromedial leg and thigh Obturator= lumbar; abductor muscles of medial thigh, small hip muscles, skin of medial thigh and hip joint Sciatic= sacral; lower trunk, posterior thigh surface, hip, knee extensor, flexors Common fibular= sacral; lateral aspect of leg and foot Tibial= sacral; (sural, plantar) posterior aspect of leg and foot, superior and inferior gluteal= gluteus muscles of hip

What are the functions of the hormones secreted by the thymus and pineal gland?

Pineal Gland= in the epithalamus, above the hypothalamus *Small, cone shape, hangs from roof of third ventricle of brain * Melatonin and secret hormones * rises and falls during day and night. Peaks at night= drowsy, low during the day *Sleep trigger= establish cycle, coordinate fertility hormones, inhibit reproductive organs until adulthood Thymus 8In upper thorax, posterior to sternum *Large in infants and children, shrinks with age *Produces thymosin= for white blood cell development (T cells)

What are the functions of the hormones secreted by the hypothalamus and pituitary gland? Describe growth hormone disorders.

Pituitary hormonal release is regulated by releasing and inhibiting hormones produced by the hypothalamus, Hypothalamus produces: oxytocin (mammary and uterine) and antidiuretic hormone ADH (kidney) (stored in posterior pituitary) The posterior pituitary is not strictly endocrine but does release hormones: anterior pituitary = glanular, posterior pituitary= nervous Anterior Pituitary Hormones: 6 Growth hormone, prolactin, thyrotropic, adenocortitropic, two gonadotropic Tropic hormone= stimulate their target organs (endocrine glands) to secrete their hormones, which in turn exert their effects on other body organs and tissues. All anterior pituitary hormones= are proteins or peptides, act through second messenger systems, and are regulated by hormonal stimuli and negative feedback Growth hormone= GH, a geneal metabolic hormone, determines final body size, protein sparing and anabolic, 1. causes amino acids to be built into proteins 2. stimulates most target cells to grow in size and divide 3. causes fats to be broken down and used for energy while it 4. spares glucose- helps to maintain blood sugar- homeostasis (too much= gigantism, acromegaly, too little= dwarfism) Prolactin (PRL) "for milk" A protein hormone, similar structure to growth hormone, target is breast, sustains milk production by mother's breasts, no known function in men Adrenocorticotropic (ACTH) Regulates the endocrine activity of the cortex portion of the adrenal gland Thyrotropic (Thyroid Stimulating Hormone TH) Influences the growth and activity of the thyroid gland Gonadotropic Regulates hormonal activity of gonads (ovaries-testes) Follicle stimulating hormone= FSH Stimulates ovarian follicle. As follicles mature, they produce estrogen, and eggs are ready for ovulation. Stimulates sperm development by testes. Luteinizing hormone LH= Triggers ovulation of an egg from ovary. Causes ruptured follicle to produce progesterone and some estrogen. In men, stimulates testosterone production by interstitial cells of testes Posterior Pituitary Hormones (hypothalamus) Oxytocin= released a lot only in childbirth and nursing. Contractions, milk ejection (let down reflex), induce or hasten labor, stop postpartum bleeding, stimulate milk ejection (prescribed) Antidiuretic (ADH)= Inhibits or prevents urine production, causes kidneys to absorb more water from the the forming urine, as urine volume decreases, blood volume increases, increases blood pressure by constricting arterioles (small arteries), also called 'vasopressin', alcohol, coffee, tea inhibits ADH secretion= more urination. (Hypo ADH secretion = diabetes insipidus, thirst)

What is a nerve plexus? How many nerve plexuses are there totally?

Plexuses= complex networks of nerves, serve sensory, motor needs of limbs, ventral rami of spinal nerves that are not T1-T12 4 nerve plexuses ; Cervical C1-C5, Brachial C5-C8 T1,Lumbar L1-L4 , Sacral L4-L5, Si-S4 plus Ventral T1-T12

What are gonads? What hormones are secreted by gonads?

Produce sex cells ( an exocrine function) Produce sex hormones identical to adrenal cortex cells Source and amounts are different= adrenal cortex and gonads Hormones of Ovaries Paired, almond sized, in pelvic, produce ova (eggs), steroid hormones; 1. Estrogen= sex characteristics, hair, organ growth 2. Progesterone= menstrual cycle, breast development, calms uterus, helps prepare for lactation * release hormones in a cyclic way * stimulated by anterior pituitary gonadotrophic hormones (3 types of estrogen: E1- only 10% of E2, postmenopausal, E2- childbearing years, E3- maintain levels during pregnancy) Hormones of Testes Makes male sex cells- scrotum, produces sex hormones= androgens Testosterone= growth and maturation of reproductive system organs, hair, heavy bones, muscles, lower voice, male sex drive, continuous production of sperm

Main function of the cerebellum

Provides precise timing of skeletal muscle activity, controls balance, equilibrium, smooth, coordinated body movements, fibers go to cerebellum from :inner ear, eye, proprioceptors of skeletal muscles and tendons, many other areas, an automatic pilot= compares brain intentions with actual body performance by monitoring body position and tension in body, sends messages to initiate corrective measures

Characteristics of a reflex. 5 elements of a reflex

Reflex= rapid, automatic, predictable, involuntary, and stereotyped response to a stimulus, one way, one direction, occurs over a highly specific neural pathway called reflex arch, involve CNS and PNS structures Reflex arch= direct route for a sensory neuron, through an interneuron to an effector, neural pathway Somatic reflexes= stimulate skeletal muscles (pull hand away from hot object) Autonomic= regulate activity of smooth muscle, salivary reflex, pupillary, regulate digestion, sweating, elimination, blood pressure 5 Elements of a Reflex 1. Sensory receptor reacts to stimulus 2. Effector organ muscle or gland eventually stimulated 3. Sensory or motor neurons connect sensory receptors and effector organ 4. Synapse between sensory and motor neurons represent the central element 5. Patellar "knee jerk" reflex= 2 neuron reflex arch, simplest type 3 neuron reflex arch= "flexor or withdrawal reflex" = limb is withdrawn after pain stimulus The more synapses there are in a reflex pathway, the longer the reflex takes Spinal reflexes involve only spinal cord neurons, not the brain Flexor reflex will work without the brain Eyes need the brain - many signals to process

Structure responsible for maintaining consciousness

Reticular Activating System (RAS) = wake/ sleep, consciousness, filters signals, weak out, strong in. Located in the reticular formation in the medulla oblongata.

Describe the structure of a sarcomere: Z line, I band, A band, and H zone.

Sarcomeres=tiny contractile units, make up myofibrils, line up like a train along length of myofibrils, myofilaments within sarcomeres create banding pattern, Two types of myofilaments within sarcomeres: thick and thin Thick filaments= "mysosin filaments", myosin protein and ATPase, enzymes split ATP to generate power for muscle contraction (for big movement), extend entire length of dark (A) band, midpoints are smooth, ends are studded with projections called cross bridges Cross bridges= have "myosin heads", link thick and thin filaments during contraction Thin filaments = "actin filaments", anchored to z disc, contain actin, a contractile protein, regulating proteins that allow or prevent myosin heads from binding to actin Actin filaments= anchored to (z disc, a disc like membrane) H zone lacks actin filaments (Light I or thin filaments) do not overlap so it is bare in the middle (called the H zone) ( the strength of muscle depends on number of sarcomeres sliding) Sarcoplasmic reticulum= specialized, smooth endoplasmic reticulum, surrounds each myofibril like a crocheted sweater, role is to store calcium and release it on demand when muscle contracts. I band= light band, only thin actin filaments, has a midline interruption called H zone, anchored to z disc ( a disc-like membrane) Dark A band= thick myosin filaments along entire length, has a lighter central area called the H zone H zone = lacks actin filaments, bare zone, the space in the middle of the myofibril where thick and thin filaments have space to slide as the muscle contracts. An M line is in the center of the H zone, it contains tiny protein rods that hold thick filaments together.

What neural supporting cells provide myelin sheath in CNS and PNS?

Schwann cells in PNS, Oligodendrocytes in CNS

What does the diencephalon consist of?

Sits atop brainstem, is enclosed by cerebral hemispheres, 3 structures:thalamus, hypothalamus, epithalamus 1) Thalamus= encloses third ventricle of brain, relay station for sensory impulses passing upward to the sensory cortex, recognizes sensations crudely as pleasant or unpleasant, neurons of sensory cortex localize and interpret sensation. 2) Hypothalamus= "under the thalamus", makes up floor of diencephalon, regulates body temperature (autonomic NSC), water balance, metabolism, center for drives and emotions= limbic system limbic system= emotional or visceral brain, thirst, appetite, sex, pleasure centers in hypothalamus, regulates pituitary gland an endocrine organ, produces 2 hormones: pituitary gland= hangs from anterior floor of hypothalamus by slender stalk mammillary bodies= reflex centers involved in smell, bulge from floor of hypothalamus posterior to pineal gland 3) Epithalamus= forms roof of 3rd ventricle, pineal gland, choroid plexus= knots of capillaries within each ventricle, forms the cerebrospinal fluid

1. Compare 3 types of muscle tissues (skeletal, cardiac, and smooth)

Skeletal muscle= packaged into organs called skeletal muscles, attach to skeleton, huge, cigar shaped, multinucleate, largest (1 ft.), striated (stripes), voluntary muscle - only muscles that have conscious control, fibers bundled together by connective tissue make them strong Smooth muscle= no striations, involuntary, visceral, found in hollow visceral organs (digestive, bowel, bladder, and blood vessels), propels substances, slowest moving muscle, fusiform/ spindle shaped cells, single nucleus, scant endomysium has two layers : one circular and one running longitudinally that take turns contracting and relaxing. Cardiac muscle = only in heart, propels blood, striated like skeletal muscle, involuntary like smooth muscle, uninucleate, cushioned by connective tissue (endomysium), arranged in a spiral or figure 8 bundles, cardiac muscle fibers are branching cells joined by junctions (intercalated discs), usually contracts at a steady rate but can be switched to high by nervous system,

How does a motor neuron control muscle contraction?

Skeletal muscles are stimulated to contract by neurons Motor unit= one neuron + all cells it stimulates Axon "nerve fiber" = long, thread-like extension of a neuron Axon terminal= branches of axons, in muscle, forms junctions with the sarcolemma of a different muscle cell Neuromuscular junctions= "nerve muscle"= vesicles with neurotransmitters Acetylcholine (Ach)= neurotransmitter that stimulates skeletal muscle cells Nerve endings and muscles never touch, the gap is called the Synaptic cleft Synaptic cleft= filled with interstitial fluid 1 nerve impulse= 1 contraction Events at the Neuromuscular Junction: 1. Action potential (electrical current) reaches axon terminal of motor neuron 2. Calcium (Ca2+) channels open and (Ca2+) enters the axon terminal 3. Ca2+ causes synaptic vessels to release their contents (acetylcholine) by exocytosis 4. Acetylcholine diffuses along synaptic cleft, binds to receptors in sarcolemma 5. Acetylcholine binds and sarcolemma channels open that allow sodium (Na+) into muscle and potassium ( K+) out. More sodium ions enter than potassium ions leave, this produces depolarization of the membrane, leads to action potential (an electrical current) 6. Acetylcholine effects are ended when it is broken down in the synaptic cleft by acetic acid and choline (acetylcholinesterose) The ion channel closes The Sliding Filament Theory: Muscle fibers are activated by nervous system -- myosin heads attach to binding sites on the thin filaments-- sliding begins Each cross bridge attaches/ detaches several times during contraction Generates tension that pulls thin filaments towards center of sarcomere This occurs simultaneously in sarcomeres throughout the muscle cell-- cells shorten Some myosin heads are always in contact with actin (the ground) so that the thin filaments cannot slide backwards again and again during contraction Myofilaments do not contract- only slide past each other Attachment of myosin cross bridges to actin requires calcium ions Calcium comes from action potential deep in muscle cell, their membrane tubules fold inward from sarcolemma, stimulate the sarcoplasmic reticulum to release calcium ions into the cytoplasm. Calcium ions trigger the binding of myosin to actin, initiating filament sliding After action potential ends, calcium ions are reabsorbed into sarcoplasmic reticulum storage Muscle relaxes and settles back to original length, this takes 1/1000th of a second. Contraction of Skeletal Muscles as a Whole: "All or None" Law = a muscle cell will contract to its fullest when stimulated. Never partially. The whole muscle reacts with a graded response. Graded response= different degrees of shortening (applies to whole muscle) 1. Produced by changing the frequency of muscle stimulation 2. by changing the number of muscle cells being stimulated at one time muscle twitches= single, brief, jerky contractions (nervous system problem) most muscles do not relax during stimuli (hence no twitches) effects of successive contractions are "summed" and get smoother Fused or complete tetanus= when muscle contracts so rapidly that no relaxation is seen, and contractions are smooth and sustained Unfused or incomplete tetanus= the muscle up until fused status- generates muscle spasm

What are the protective structures of the brain and spinal cord?

Skull, vertebral column, membranes (meninges), cerebrospinal fluid (watery cushion), blood brain barrier protects from harmful substances in blood

Difference between general and special senses.

Special senses include: smell, taste, sight, hearing, and equilibrium. Large, complex sensory organs (eyes and ears), or localized clusters of receptors (taste buds, olfactory epithelium. General = touch

Difference between static and dynamic equilibrium.

Static equilibrium Maculae= within membranous sacs of vestibule 'spots', report changes of head in space with respect to gravity, up and down one maculae= patch of receptor (hair cells) with their 'hairs' embedded in otolithic membrane- a jelly mass studded with otoliths otoliths= tiny stones made of calcium salts, roll in response to head movements, gravity changes. The gel pulls, bends hairs, activates hair cells, they send impulses to Vestibular nerve ( a division of cranial) to the cerebellum of brain to inform it of head position Dynamic Equilibrium Receptors in semicircular canals, respond to angular or rotary movement of head, 1/3 inch around, oriented in 3 planes of space Crista ampullaris= within ampulla-(swollen region at base of each membranous circular canal) Receptor region= tuft of hair cells, covered with cupula- a gelatinous cap Cupula bends, drags with body motion, stimulates hair cells- impulses are transmitted 'like a swinging door'

What are the mechanisms of actions for steroid and non steroid hormones?

Steroid Hormones= Direct Gene Activation- Non steroid hormones= Second Messenger System (mechanism by which hormones trigger changes in cells) Direct Gene Activation Lipid soluble, used by steroidal and thyroid 1. Diffuse through plasma membranes of target cells 2. enter nucleus 3. Binds to specific hormone receptor, the hormone receptor complex then 4. Binds to specific sites on the cell's DNA 5. Activates certain genes to transcribe mRNA, the mRNA then 6. is translated into the cytoplasm resulting in synthesis of new proteins Second Messenger System *slower Water soluble, non steroidal, protein and peptide hormones are not able to enter target cells. They bind to hormone receptors on the target cells' plasma membrane and utilize a second messenger system 1. The hormone (1st messenger) binds to the membrane receptor 2. The activated receptor sets off a series of reactions (a cascade) that activates an enzyme. In turn- 3. The enzyme catalyzes reactions that produce second messenger molecules (cyclic AMP or adeninemonophosphate) that- 4. Oversee additional intracellular changes that promote the typical response of the target cell to the hormone

Difference between sympathetic and parasympathetic nervous divisions

Sympathetic= mobilize body during extreme situations, fear, exercise, rage,dilates eyes, lungs,blood vessels, increases heart rate,blood pressure, remove blood from digestive organs, blood glucose levels ,fight or flight, release norepinephrine, "adrenergic" Parasympathetic= allows us to unwind and conserve energy, rest and digest, release acetylcholine, "cholinergenic", controls most blood vessels even when on alert, conserve body energy

What structure determines eye color?

The iris.

What structure is responsible for accommodation?

The lens. Accommodation= the ability of lens to focus on close objects

Location of thenar eminence and hypothenar eminence

Thenar = "palm of hand" group of muscles on palm of hand at the base of the thumb. Abductor pollicis brevis 9abduct thumb), flexor pollicis brevis (flex thumb), opponens pollicis (oppose thumb) Hypothenar = the three muscles of the palm that control the little finger. Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti brevis (A OF A OF A)

5. Examples of myofilaments: thick "myosin filaments" and thin "actin filaments"

Thick filaments= "mysosin filaments", myosin protein and ATPase, enzymes split ATP to generate power for muscle contraction (for big movement), extend entire length of dark (A) band, midpoints are smooth, ends are studded with projections called cross bridges Cross bridges= have "myosin heads", link thick and thin filaments during contraction Thin filaments= "actin filaments", contain actin, a contractile protein, regulating proteins that allow or prevent myosin heads from binding to actin Actin filaments= anchored to (z disc, a disc like membrane) H zone lacks actin filaments (Light I or thin filaments) do not overlap so it is bare in the middle (called the H zone)

What are the functions of thyroid hormones? Describe thyroid hormone disorders.

Thyroid gland = makes 2 hormones: thyroid hormone and calcitonin, located base of throat, two lobes joined by central mass- isthmus, gland made of hollow follicles storing sticky colloidal Thyroid Hormone= The Body's major Metabolic Hormone derived from sticky colloidal, is two, active iodine containing hormones: 1. Thyroxine (T4)= major hormone secreted by thyroid 2. Triodothyronine (T3)= formed at target site by conversion of T3-T4 Alike, both constructed from two tyrosine amino acids linked T4 Thyroxine has four bound iodine atoms, T3 Triiodothyronine has three bound iodine atoms *Controls rate at which glucose is burned or oxidized *Targets every cell in body *Normal tissue growth, development (especially in reproductive, nervous systems) Thyroid disorders caused by lack of iodine: goiters-low iodine cretinism- hyposecretion (too little) of thyroxine myxedema- hyposecretion of thyroxine continuing into adulthood Grave's disease- hypersecretion exophthalomas- hyper secretion

Dorsiflexion and Plantar flexion of foot

Tibialis Anterior- superficial, anterior leg. Origin: upper tibia, parallels anterior crest, runs to tarsal bones. Inserts: by a long tendon (dorsiflex and invert foot) Extensor Digitorum Longus- lateral to tibialis anterior, arises from: lateral tibial condyle and proximal 3/4 of fibula. Inserts: into phalanges of toes 2-5 (prime mover of toe extension) Fibularis Muscles: 3: longus, brevis, tertius (lateral leg) Arise from fibula, Insert; metatarsal bones of foot. (plantar flexes and everts foot) Gastrocnemius- 2 bellied, curved calf of posterior leg, arises by two heads: one from each side of distal femur. Inserts: large calcaneal (achilles) tendon into heel of foot. (prime mover for plantar flexion of foot, called "toe dancer's muscle", keeps heel lifted) Soleus- deep to gastrocnemius, fleshy, Arises: tibia and fibula Inserts: calcaneal tendon (strong plantar flexor of foot)

"Boxer Muscle"

Triceps brachii- only muscle fleshing out posterior humerus, 3 heads arise: shoulder girdle, and proximal humerus Insert: olecranon process ulna (elbow extension prime mover, antagonist of biceps brachii, "boxer muscle" seratus anterior

When is human chorionic gonadotropin detected in urine and blood?

Very early pregnancy. Is produced by developing embryo and then by fetal part of placenta. Stimulates ovaries to continue producing estrogen and progesterone so that lining of uterus is not discarded.

White vs. grey matters of brain and spinal cord.

White matter= collection of myelinated fibers, internal area Gray matter= unmyelinated fibers and cell bodies

Differences between rods and cones

Within neural layer, also called photoreceptor cells that are everywhere except optic disc and distributed evenly. Rods= receptor cells, in millions, densest at periphery or edge, decrease towards center. Allow us to see in gray tones, in dim light, and provide peripheral vision. (night blindness is deficiency vitamin A, rods need A to respond to light) Cones= photoreceptors, respond to light, discriminating receptors, see in color, bright light, densest in center, decrease toward edge. Fovea centralis= lateral to blind spot, tiny pit, only cones, area of greatest visual acuity 3 Varieties of Cones; Blue cones 420 nm, Green cones 530 nm, Red cones 560 nm- respond to both blue and green, only ones that respond to red Intermediate colors= two cones receiving impulses at the same time Color blindness= lacking all three cone types, most common in red and green lacking, mostly males

3. Functions of skeletal muscles:

maintains posture, stabilizes joints, generates heat (ATP), accounts for 40% of body mass, multinucleate, protects fragile organs, forms valves, dilates/constricts pupils, arrector pili,

Prime movers

mastication ; Buccinator= runs horizontally across cheek, inserts into orbicularis oris (chewing, flattens cheek) Masseter= runs from zygomatic process of temporal bone to mandible, covers angle of lower jaw, closes jaw by elevating the mandible. Temporalis= fan shaped muscle overlying the temporal bone, inserts into mandible, acts as synergist of masseter in closing the jaw Flexion, extension, rotation of head and neck: OOO Sternocleidomastoid= paired, one each side of neck, 2 headed. One head arises from sternum, the other one arises from clavicle. Heads fuse before inserting into mastoid process of temporal bone. When they contract, they flex the neck= "prayer muscles" bow head. One contracts= head rotates toward shoulder on opposite side and head tilts to contacting side. Trapezius = most superficial of posterior neck and upper trunk, forms a diamond, runs from occipital bone of skull, down vertebral column to end of thoracic plane laterally to insert on scapular spine and clavicle. (extends the head, elevate, depress, abduct, stabilize scapula, antagonist of sternocleidomastoid) Respiration: Intercostal muscles= deep, between ribs. External intercostals = breathing, help raise ribcage on inhale. Internal = lie deep to external, depress ribcage, move air out on forced exhale Compression of the Abdomen: Rectus abdominus= paired, strap like, most superficial of abdomen. From pubis to ribcage, enclosed in aponeurosis, flex vertebral column, compress for excretion, childbirth, forced breathing Transverse abdominus= deepest of abdominal wall, fibers horizontally across abdomen, arises lower ribs and iliac crest, inserts into pubis, compresses abdominal contents Extension of spine: Erector spinae = prime mover of back extension, paired, deep in back, consists of 3 muscular columns : longissimus, iliocostalis, spinalis. Spans entire length of vertebral column (back extensors, resistance that controls bending at waist) Quadratus lumborum = fleshy, part of posterior abdominal wall, acts separately, each muscle flexes spine laterally. Together, they extend lumbar spine. Arises from iliac crest, inserts at upper lumbar vertebrae

Define: nerve cell, nerve fiber, fascicle, epineurium, perineurium, and endoneurium

nerve= a bundle of neuron fibers found outside the CNS Neuron fibers= inside nerve, "processes" that are wrapped in connective tissue coverings Endoneurium= delicate connective tissue sheath, around each nerve fiber Perineurium= binds groups of fibers, coarser connective tissue Fascicles= fiber bundles Epineurium= binds all fascicles, tough fibrous sheath, forms nerve Classified according to direction they transmit impulses Mixed nerves= nerves carrying both sensory and motor fibers Sensory= nerves that carry impulses toward CNS (afferent) Motor or efferent= nerves that carry only motor fibers