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Fans: sensory (external/internal stimuli), transmits info to brain/spine, integration (processes info in brain/spine), motor (sends info to muscles/glands/organs), maintain homeostasis. Neuron: transmits impulses; dendrie receives stimulus + carries toward cell bodyhas nucleus- then to. axon: fiber, carries impulses away trom cell body; sehwann cell: produce myelin in PNS; myelin sheath: lipid layer, insulates axon; node of ranvier: gaps in myelin sheath, Sensory (bring messages to CIS, afferent pathway), motor (send from CNS, efferent pathway), interneurons (I+ synapses btwn sensory/motor neurons in CNS). Impulses: stimulus, excitability (ability of neuron to respond and create impulse), all of nothing rule: stimulus strong enough to start impulse or nothing happens; self-propagation: once impulse starts it flows only in its 1 direction. Synapse: gap btwn axon of | neuron and dendrite of other, uses neurotransmitters to start impulse or an effector (muscle or gland), ensures one-way transmission. Newrodransmitters: chemicals in jet allowing impulses to start. CNS: brain (brain stem; diencephalon- thalamus, hypothalamus; cerebellum, cerebrum), spine (spinal cord). Meninges: 3 coverings around brain/spine, protect + nourish them; dura mater: tough outer layer; arachnoid mater: adheres to dura mater and has weblike attachments to pia mater: thin, clear, tough; cerebrospinal fluid: buffers, nourishes, detoxifies brain’spine, flows in subarachnoid space btwn arach, mater/pia mater. Brain: Cerebelliem (coordination of movement, motor learning, attention, language), Ceredrum (conscious activity- perception, emotion, thought, judgment, planning; has lobes, cer. cortex, med body, basal ganglia) eortex: (gray matter (cell bodies + synapses, no myelin), folded bulges, gyri, create deep furrows called suici. Folds increase gray matter + processable info.) Thalamus (lilters then relays sensory info except smell to brain regions, cortex 4 interp. Descending fibers into cerebral cortex, awareness of pain/touch/temp), Medulla (vital reflexes- heart beat, respiration; white matter, myelinated axons), basal ganglia: gray matter masses, voluntary movement Limbic System: strxrs (amygdala, hippocampus [short-term into long-term memory], septum, basal ganglia, etc), regulate expression of emotions, emotional memory, assoc. feelings w/ sensations. Brainstem (medulla oblongata, pons, and midbrain send info btwn cerebrum + body, att to spinal cord (involuntary responses eg digestion, heart, BP, sleep patterns, hunger/thirst], relays info from spine to upper brain; Hypothalamus (regulating internal organs, monitoring info from the ANS, regulate sleep/appetite, body temp with thermo- and osmoreceptors causing sweating or shivers, blood flow, pituitary) brain waves- electric potential btwn regions, seen on electroencephalagram w/ electrodes, active-sleep: beta/alphartheta/delta. PNS: 12 pair cranial nerves (undersurface of brain, this + corticospinal tract + posterior column-medial meniscus pathway + spinothalamic tract: sent motor/sensory feeling to face/neck), 31 spinal nerves. SNS (somatic-voluntary), ANS (autonomic-involuntary; sympathetic. emergency, fight/flight & parasympathetic- normal) diencephaion- cerebellum, (hypothalamus. Commissural fibers: conduct impulses bwn hemis, form corpus callosum Projection fibers: conduct impulse in/out of cerebral hemis Association fibers: conduct impulses w/in hemis, Neuroglia: non- neuronal cells that maintain homeostasis, form myelin, provide support and protection for neutrons in central and peripheral nervous systems. Glial cells (oligodendrocytes, astrocytes, ependymal cells and microglia), peripheral glial cells (schwann cells and satellite cells) Glial cells: support‘supply o2/insulate neurons, destroy pathogens and remove dead neurons. Frontal lobe: conscious thought/personality’ planning/morality/comparecontrast, anterior to central sulcus, Posterior portion has precentral gyrus (Somatomotor or primary motor cortex) -- voluntary motions processed. Motor homunculus represents portions of body which motor cortex controls; Maturity: 20 yrs; Broca’s area (speech. prdxn) Parietal lobe: spatial processing, navigation abilities, sensory, language. (Posterior to central sulcus and frontal lobe) In anterior portion—-somatosensory ox primary sensory cortex (genitalia, breasts). Occipital lobe: processes visual images (posterior and interior to parieto-occipital sulcus) Temporal lobe: visual memory, object recagnition, sound/smell processing, language processing (inferior to lateral sulcus or sylvian fissure); wersicke's area (language comprehension, meaningful speech) epilepsy: recurrent seizures, abnormal electrical activity when neurons send wrong messages, caused by illness, stroke, damage, unknown. alzheimer's disease connections bwn networks of neurons break down be increased plasma osmolality, shrinking brain regions until atrophy, multiple sclerosis: autoimmune; inflammatory lesions—rneuronal demyelination, axonal damage, neurological dysfunctions bc of plaques in gray/white matter, impaired movement and senses; parkinson’s disease: tremors/movement/speech impaired bc loss of dopamine be breakdown of neurons, cerebral palsy: movement/balance/posture, exag, reflexes be abronal brain development b4 birth, shingles/herpes zoster: reactivation of varicella-zoster virus, in cranial nerve, rashiinflamm., stroke ischemic-insuffic. 02 to brain, hemorrhagic- leaky blood vessels, depletes ATP so Na/Ca gradient disrupted. ALS: amyotrophic Lateral selerosis, mutation causes motor neurons to get damaged, mavement/eognitive impairment. / Receptors: mechano- (pressure/stretel; movement/balance) therm- (skin/viscera; intemal/extemal response) pain (stim, by lack of 02, chems released ftom damaged cells) chema- (detect 02/co2/ph changes) photo- (ight-stim.ed). special senses (vision, hearing, equilibrium, taste, smell) mediated by sense organs innervated by cranial nerves. General receps: skin, muscle, joints, tendons, pain (somatic or visceral), somesthetie: area of cerebral cortex receives sensory info from somatic senses + proprioceptive senses+ visceral); touch organs, proprioception, temp, BP. Eye: light into neural activity, neural activity processed: objects reflecting light, IDed by size. shape, color, memory; movement detected in most light. Light focused to retina w/ comea/lens—retina converts light (upside-down/backwards)—retinal axons (carry nerve impulses away from cell bady) form optic nerve—-visual info distributed to diff brain parts. Outer layer-selera/comea; middle-choraid/ciliary body/iris; inner-retina; extraocular muscles (atlach eye to scull; movement). Sclera: protective connective tissue, maintain shape, provide attached for muscles. Conjunctiva: membrane w/in eyelid, att to sclera; cornea: clear, dome-y part of sclera, covers iris/pupil comea'+pupil; aqueous humor: fluid fills anterior chamber, maintains shape, nutrients for lens/cornea, waste management; choroid layer: middle layer w/ blood vessels; ciliary body: citcular muscle band behind iris, produces aq humor, changes shape of lens to focus; iris: circular muscle controls pupil diameter, pigmented portion of choroid layer w/ blood vessels; lens: erystalline strxr behind iris, focuses light onto-retina; pupil: allows light to reach retina; vitreous: thick/clear fluid/h2o, fills eye center, gives shape; retina sensory tissue @ back, photoreceptors (rods for black/white, wavelengths but not coloriclarity; cones=color, red/green/blue [daytime view) convert light rays—selectrical impulses relayed to brain via optic nerve, which merge @uptic chiasm, where R+L eye info crosses over. Ophthalmoscopic appearance: optic disk is blind spot where blaod vessels originate (shadow retina), optic neve fibers exit eye (no photorcptrs), macula: retina 4 central vision, fovea: retina center w/ cones.Myopia: nearsightedness be eye shape ta0 long so light from cornea funnels too soon, hits retina wrong; hyperopia farsighted, shape too short, light from cornea hits retina too soon. Presbyopia: slow loss of sight be weakening ciliary muscles and lens flexibility (old age). Nyctalopia: can’t see diny/dark light be retinitis pigmentosa- rod cells can't respond to light. Astigmatism: irregular shaped curvature of eye, light bends wrong, blurry vision. conjunctivitis/pink eye: conjunctiva inflamed. Color blind: inherited, faulty photopigments (mes detect color in cones) Ear eardrum: vibrates to amplify sound, separates inner/middle; middle- ossicles (anvil/stirrup’stapes) amplify sound; eustachian tbe: connects middle ear to throat, equalizes eardrum pressure. Cachea: receptors for sound, sends signals to brain via auditory nerve, Process: sound waves enter outer, flow thru canal to eardrum, it vibrates, passes vibrations into hammar, it makes anvil vibrate, it makes stirrup vibrate, sends to inner ear through liquid sac, passes to cochlea and vestibular system (3 canals responsible for sense of balance and spatial orientation, has otoliths w/ calc. Carbonate, movement of otoliths over small haits inside pathway send signals to brain to separate sound), crisia ampuitaris: repir region, tuft of hairy cells w/ cupua (gelatinous cap). otis media (ear infec):eustachian tube dysfunction or middle ear inflamed. Hearing loss: conductive (sound doesn’t reach outer/middle ear) sensorineural (inner earnerve pathways damaged, can cause SNHL) mixed (conductive w/ or bc of the 2nd), Taste 10,000 buds perceive: sour/sweet/bitter/salty/ umami (salts of some acids); hair on reptr catches chemicals on food, sends nerve impulses, taste/Smell intertwined; dysgeusia all food sour, sweet, bitter, or metallic; causes: infection, medications, vitamin deficiencies. Smell Anosmia: loss of smell, inherited (olfactory system develops wrong) or disease. Dysosmia: peripheral neurological causes (altered firing of reprs in regen) or central lesions skin: meissner‘s corpuscles: in capsule of cnnctv tissue, light touch, palms/soles/lips/eyelids; merkel dises btwn epi- and dermis; root hair plexus: base of hair follicle; pacinian corpuscles: deep pressureivibration (layrs of schwann cells w/in cnnctv tissue), on-off pressure; ruffini's endings/krause's end bulbs: pressure sensors, dermis mainly, continuous pressure; nociceptors: visceral (maintain homeostasis) somatic (skin/skeletal muscle, lack of 02, inflammation); proprioceptors: stretch reptrs, in joins/ligaments/tendons, continuous contraction; muscle spindles: muscle fibers wi sensory nerve, detect stretch, stimulate reflex. / Exocrine glands discharge secretions via duct to targeted tissue (sebaceous, salivary glands). Endocrine glands release hormones into bloodstream w/o ducts; epithelial tissue. Hormones: signaling mes, chemical messengers; most follow (-) feedback loop or closed loop system, (++) feedback includes lactation & labor contractions, eg: hypothalamus prices oxytocin, transported to posterior pituitary & released, stimulates uterine contraction, loop stops when baby exists birth canal, Hypothalamus: [ADH, oxytocin, regulatory hormones], attached to posterior pituitary; controls pituitary secretions thru nervous stimulation (posterior pituitary) and releasing hormones secreted to anterior pituitary, neurosecretory cells: neurons, synthesize/secrete hormones. Pituitary controls other glands, located in sella turcica of sphenoid bone, body/tissue growth, endorphins-reduce sensitivity to pain. Anterior/adenohypophysis F'SH- follicle stim. Horm & LIf- luteinizing horm — regulate estrogen & progesterone, go to ovary/testes; TSH (ells thyroid to release thyroxine), ACTH. adreno-corticotropic horm. stims adrenal cortex secretions, GH, MSH- melanocyte-stim. horm, (melanin prdxn), prolactin (milk). Posterior/neurohypophysis oxytocin (contractions in childbirth; milk release from breast tissue), ADH- antidiuretic horm, (—+kidneys to reabsorb more h20). Diabetes insipidus=hyposeeretion ADH=excess dilute urine excreted. Pineal: in brain; melatonin (regulates sleep-wake cycle). Thyroid wraps around trachea: thyroxine (T) (regulates metabolism|/mood’ body temp}: stimulates cell respw/ cone in blood; iodine needed 4 prdxn) triiodothyronine (T4) (digestive/metabolic fn, bone health) CT -calcitonin. eretinism: hypoth. in infancy- deformity/learning disabilities [myxedema is in adult}; Graves": autoimmune, antibodies sent to TSH receptor—hyperthyr, Hashimoto's thyroiditis: lymphocytes invade tissue, hypo goiter: mostly lack of iodine, graves/autoimmune cause; can be hereditary, risks: female, 40+ age. Parathyroid: 4 on back of thy PTH- parathy horm. regulates Ca in blood/its absorb. by bones. (Hypoparathyr-muscle tetany; hyperparathy-osteitis fibrosa cystica=bone demi- neralization) Adrenal suprarenal medulla: E-epinephrine, NE-norepinephrine[cont. release] (regulate fight/flight response/stress) suprarenal cortex: aldosterone (regulate reabsorp of nutrients from kidney), cortisol (metabolism rate of carbs, fats, proteins) corticosterone {stress- external), androgens (male sexual/ reproductive fxn); tumors cuase hypersec. of medullary hormones {prolonged fight/flight}; cushings’-eortisol hyper; addison’s=aldosterone/ glucocorticoids hyposee Pancreas behind stomach; insulin (causes liver/museles to remove sugar from blood + store as fat), glucagon (liver break down fat stores/release sugar into blood) diabetes mellitus: !=insuline-dep (abs. deficiency), I= -indep. (down-reg of insulin receptors); hyperinsulinemia—> hypoglycemia Ovaries estrogen’ progesterone [endometrium secretes when egg binds to it, stap cycle] (regulate menstrual cycle), inhibin- stop FSH, LH, Testes androgens: testosterone- sex organs, sperm develoment, puberty, ete) + inhibin. Kidney erythropoietin (bone marrow make RBCs), calcitriol (ea, phos lvls), renin (blood press, more raises) Mechanism:cell response eg: phosphorylation, activation of enzymes to release Ca2+ into cytosol, tum on transcription factor CREB for protein prdxn.; peptides: short amino-acid chains, glycoproteins (most hormones), eg insulin’ TSHV/hypothalamus/pituitary; amines: tyrosine deriv-thyroid, dopamine, epineph, norep; tryptophan deriv-melatonin; steroid horm.s: fat-soluble, intracellular, steroid-recept complex binds to steroid response clement (sections of DNA receptive to- complex), complex acts as transeription factor to turn on/off genes, ex androgens, est/prog, suprarenal glands (corticosteroids), kidneys (caleitriol); eicosanoids: from arachidonic acid, act ashormones 2ndry ficn, include leukotrienes (from WBCs), Hormone prostaglandins 1g 3. Hormones of the posterior and anterior pituitary Hyoothalpmie-paltory portal eXEaatony tre ee | ne) Lf. 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