Comprehensive Exam Review PDF

Chapter 1: Physiology Introduction & Homeostasis Physiology - study of living functions ○ Mechanisms of actions Body Organization ○ Chemical - atoms and molecules (Carbon, Proteins) ○ Cell, Tissue - muscle, nervous, epithelial, connective ○ Organ,...

Chapter 1: Physiology Introduction & Homeostasis Physiology - study of living functions ○ Mechanisms of actions Body Organization ○ Chemical - atoms and molecules (Carbon, Proteins) ○ Cell, Tissue - muscle, nervous, epithelial, connective ○ Organ, Organ System, Organism Cell Functions: ○ Obtain Food ○ Make energy ○ Cleanse environment ○ Make cell components (proteins) Secrete enzymes ○ Exchange materials with environment Reabsorption of materials ○ Internal movement of materials Muscle contractions ○ Change to environment changes Active potential ○ Reproduce (most cells; nerve/muscle exception) extracellular fluid made of plasma (liquid), and interstitial fluid (glue) Factor Regulated by Homeostasis ○ Nutrient, water, and electrolyte concentration ○ O2 and CO2 concentrations ○ Waste product concentration ○ pH, volume, and pressure of ECF ○ Temperature Intrinsic homeostatic control systems - inherent to organ Extrinsic homeostatic control systems - regulated by other organ/system (common) Positive feedback loops must have an exit point, else problems occur (cancer) Feedforward mechanism - reacts to anticipation of change (insulin when food enters) Chapter 2: Cell Physiology Cell Theory ○ Cell is the smallest possible living thing ○ Cell activity depends on structure ○ Cells make up all organisms ○ An organism depends on characteristics of its cells ○ All cells come from other cells All cells are similar Smooth ER detoxifies, stores Ca2+, produces steroids & modifies proteins RNA Types: ○ Messenger (mRNA) - brings code for ribosomes ○ Ribosomal (rRNA) - translates mRNA into protein ○ Transfer (tRNA) - brings amino acids to mRNA ○ Micro & small interfering (mi/siRNA) - binds to mRNA to regulate RNA interference (RNAi) Proteome - set of proteins that can be expressed; dependant on cell type Lipidome - full set of lipids in body cells Membranous organelle - organelle enclosed by plasma membrane-esque layer Non Membranous organelle - organelles with direct contact with cytoplasm Proteasome - non-membranous; looks for ubiquitin-tagged proteins for destruction Peroxisome - membranous; produce/decompose H2O2 to degrade toxins ○ Has oxidative enzymes & catalase Cellular Respiration ○ Glycolysis: glucose → 2 ATP & 2 pyruvate ○ Krebs Cycle: pyruvate → 2 ATP & electrons w/ 3 NADH & 2 FADH2 ○ Oxidative Phosphorylation: electrons & O2 → 28 ATP, NAD+, FADH+, CO2 Microtubules - preserve shape/position of organelles & act as cell highway Microfilaments - mechanical movement of cells (contractions/stiffeners) Intermediate Filaments - maintain cell structure/integrity Chapter 3: Plasma Membrane/Membrane Potential Functions of membrane proteins: ○ Form channels ○ Serve as carriers & docking-marker acceptors ○ Membrane-bound enzyme ○ Receptor ○ Cell adhesion molecule (CAM) ○ ‘Self’ recognition ECM works as biological glue Some cells linked by cell junctions: ○ Desmosome - connects two closeby cells, strongest, resists stretching ○ Tight junctions - seals passageway between two touching cells, filler ○ Gap junctions - connects two closeby cells, like tunnel for ions/small molecules Factors of Fick’s Rate of Net Diffusion Law: ○ Concentration Gradient [increases] ○ Membrane Surface Area [increases] ○ Lipid Solubility [increases] ○ Molecular Weight [decreases] ○ Membrane Thickness [decreases] Primary active transport - ATP is split by carrier to produce uphill movement Secondary active transport - another form of energy is used to produce uphill movement ○ That form of energy is usually created by primary (ion concentration gradient) Symport - carrier and molecule move in same direction across membrane Antiport - carrier and molecule move in opposite direction across Nernst Equation (Resting Potential) = 61log(Coutside/Cinside) Cell is negatively charged due to anionic proteins Membrane Potential Ion Characteristics ○ Sodium (Na+) ECF:ICF Concentration = 150:15 [10:1] Relative Permeability = 1 Membrane potential = 61mV ○ Potassium (K+) ECF:ICF Concentration = 5:150 [1:30] Relative Permeability = 25-30 Membrane potential = -90mV GHK Equation (Membrane Potential) 𝑃𝐾[𝐾]𝑜𝑢𝑡+𝑃𝑁𝑎[𝑁𝑎]𝑜𝑢𝑡 ○ 𝑉𝑚 = 61𝑙𝑜𝑔( 𝑃𝐾[𝐾]𝑖𝑛+𝑃𝑁𝑎[𝑁𝑎]𝑖𝑛 ) PX = permeability of ion X ○ Resting Membrane Potential = -70mV Chapter 4: Neural/Hormonal Communication Hypopolarization - membrane potential increases (less negative) Repolarization - membrane returns to resting (-70mV) Hyperpolarization - membrane potential decreases (more negative) Types of gated channels: ○ Voltage gated (based on membrane potential) ○ Chemically gated (based on molecules) ○ Mechanically gated (based on stretching/other movements) ○ Thermally gated (based on temperature) Types of Electrical Signals: ○ Graded potentials Local changes; differing magnitude Strength/Duration dependant on triggering event Spreads by passive current flow; die out over short distances ○ Action potentials Initiated by graded potential; brings potential to -55 to -50mV Sharp and fast hypo, re, then hyperpolarization Action potential steps: ○ Hypopolarization: Na+ channel opens fast (activation); K+ channel opens slowly ○ Repolarization: Na+ channel closes (inactivation); K+ channel fully open ○ Hyperpolarization: Na+ channel closes (activation), resets (inactivation); K+ channel closes slowly + + Na /K pumps resets concentration after action potentials, but does not affect actual action potential Neuron (left-to-right) - dendrites (input), cell body, axon hillock (action), axon (travel), axon terminals (end) Refractory periods: ○ Absolute: Na+ channels already open, cannot be opened again ○ Relative: Na+ channels need to reset, K+ channels still open action potential can still happen, trigger has to be much stronger Stimulus strength depend on frequency of action potentials (duration/strength is fixed) How to transfer action potentials faster: ○ Myelin formed by Schwann cells mean action ‘jumps’ between open nodes of Ranvier; saltatory conduction ○ Increase fiber diameter Electrical synapse - two neurons connected by gap junction, always leads to action Chemical synapse - two separated neurons, chemical messenger sends information ○ One way; more common; Ca2+ is ligand for a receptor for Na+ channels  Excitatory postsynaptic potential (EPSP) - excitatory synapse; brings potential closer to threshold ○ Large influx of Na+, small efflux of K+ via chemical gates Inhibitory postsynaptic potential (IPSP) - inhibitory synapse; brings potential further away from threshold ○ Large efflux of K+ via chemical gates, influx of Cl- Neurotransmitters for EPSPs and IPSPs quickly destroyed; enzymes in postsynaptic cleft Grand postsynaptic potential (GPSP) - sum of all EPSPs/IPSPs in postsynaptic neuron Types of summation for GPSP: ○ Temporal - several PSPs from same presynaptic neuron in quick succession ○ Spatial - single PSPs from multiple neurons at the same time Neuromodulators - chemical messenger; modulates synapse action ○ Neuropeptides, ATP, NO, endocannabinoids ○ Either facilitates or inhibits presynaptic action Cell communication mainly by extracellular chemical messengers ○ Gap junctions/tunneling nanotubes ○ Transient direct linkup of surface markers (signal molecules) Types of extracellular chemical messengers ○ Paracrines/autocrines - local (neighboring cells/same cell) ○ Neurotransmitters - short range ○ Hormones - long range ○ Neurohormones - released by neurosecretory neurons Signal transduction - process by which signals travel to target cell ○ For lipid-soluble - functions in nucleus to change gene activity (genomic) ○ For water-soluble: (non-genomic) Bind to receptor-channels; may open said channel Bind to receptor-enzyme complexes Activates intracellular protein kinases → cascades tyrosine kinase pathway - receptor works as enzyme JAK/STAT pathway - receptor/enzyme works as a unit Bind to G-protein-coupled receptor; activates second messengers Cytokines - intercellular; secreted by WBC (immune); protein → for growth factors Eicosanoids - locally acting; derived from plasma membrane; lipid; regulates a lot Hormones affect by altering intracellular proteins Hydrophilic hormones - peptides (affects existing proteins mainly by phosphorylation) Lipophilic hormones - steroids; mainly cholesterol (forms new proteins; transcription) ○ Carrier proteins help it travel through liquid Secondary messenger systems: (Can affect multiple pathways (amplification)) ○ Adenylyl cyclase (cAMP) ○ Phospholipase C (IP3, Ca2+, DAG) Chapter 15: Fluid & Acid-Base Balance [Acid-Base not on Exam] Body Water = 60% of body mass ○ ICF = 40% of body mass ○ ECF = 20% of body mass Plasma = 20% of ECF Interstitial fluid = 80% of ECF ICF ion composition: mostly K+ and PO43- ECF ion composition ○ Plasma: mostly Na+ and Cl- ○ Interstitial fluid: mostly Na+ and Cl-; no protein anions ECF volume integral to maintain blood pressure (salt balance) ○ Short term: Baroreceptors and fluid shifts between ECF components ECF osmolarity integral to cell tonicity (water balance) Neural/Hormonal Communication [113-127] Agonist - binds/activates receptors Antagonist - receptor (blocks activation) and physiological (activates opposing system) Direct intercell comms ○ Gap junctions/tunneling nanotubes (large cargo across long distance) ○ Surface marker linkup (signal molecules) paracrines/autocrines - neighboring/self effect Neurotransmitters - short range chemicals; synapse Hormones - long range chemicals; endocrine Neurohormones - hormones secreted by neurosecretory neurons Signal transduction - how signals conveyed to target cell ○ Lipid soluble - nucleus; change gene activity ○ Water soluble bind/activate/deactivate chemical receptor channels bind/activate receptor enzyme complexes tyrosine kinase - receptor is enzyme (insulin, GFs) JAK/STAT - receptor + enzyme = unit (prolactin) Bind to G-protein receptors - activate second messengers Paracrine types: ○ Cytokines (protein) - local; regulate immune + growth factors ○ Eicosanoids (lipid) - local (from plasma membrane); many functions Hormone classes: ○ Solubility: determines hormone creation, transportation, effect ○ Hydrophilic - peptides/amines Precursor (preprohormones) to ER/Golgi to secretion Travels via dissolving in plasma; binds to extracellular  Alters pre existing proteins (cAMP) ○ Lipophilic - steroids Precursor (cholesterol) to enzyme modification to diffusion Travels via attaching to plasma proteins; binds to intracellular Forms new proteins (changes transcription) Nervous system - swift, electrical, innervated tissues (wired) ○ Determined by proximity to neurons endocrine system - hormonal, blood, distant cells (wireless) ○ Determined by specialized receptors Endocrinology [638-646] Hormone half life determines activity length ○ Peptides and catecholamines - short ○ Steroid and thyroid - long Tropic hormone - regulates secretion of another hormone Factors affecting effective plasma concentration of hormones ○ Rate of secretion by endocrine glands Negative feedback, neuroendocrine reflex, circadian rhythm ○ Rate of activation/conversion (some) ○ Extent of binding to plasma proteins (lipophilic) ○ Rate of metabolism/excretion Endocrine disorders origins: hyposecretion, hypersecretion, abnormal target-cells Receptors change target cell responsiveness ○ Down regulation (high levels → less receptors → desensitized) ○ Permissiveness (other hormone makes original function at max capability) ○ Synergism (multiple hormones perform same function) ○ Antagonism (hormone causes loss of another's receptors) Anterior/Posterior Pituitary [646-652] Pituitary gland made of two parts: ○ Posterior (nervous; neurohypophysis) ○ Anterior (gland epithelial; adenohypophysis) - mostly tropic hormone Hypothalamus + posterior = vasopressin/oxytocin secretion ○ Vasopressin (ADH) - conserves H2O in kidneys, artery muscle contractions Hyposecretion - diabetes insipidus ○ Oxytocin - contraction of uterine muscle, milk ejection Anterior hormones: ○ Growth (GH) - body growth/metabolism ○ Thyroid-stimulating (TSH) - stimulates thyroid secretion/growth ○ Adrenocorticotropic (ACTH) - stimulates cortisol secretion/cortex growth  ○ Follicle stimulating (FSH) - regulate gamete (sex cell) production ○ Luteinizing (LH) - control sex hormone secretion (estrogen/testosterone) ○ Prolactin (PRL) - enhance breast development/lactation Hypothalamus hormones regulate anterior via portal system ○ Two capillaries, hormones circulate between them Target gland hormones inhibit hypothalamic/anterior hormones via negative feedback Adrenal (Medulla/Cortex) [672-685] Adrenal glands made of cortex (outer zona) and medulla (inner modified neurons) ○ Cortex secretes steroids Mineralocorticoids (aldosterone) - keep Na+, excrete K+, blood pressure up Controlled by ions (negative feed) Glucocorticoids (cortisol) - increase blood nutrients, permissive, immune Controlled by ACTH, controlled by CRH (negative feed) Sex hormones (androgens/estrogens) - DHEA for female ‘male’ processes Controlled by ACTH ○ Medulla secretes catecholamines Epinephrine - helps sympathetic nervous system and glycogenolysis Released in sympathetic stimulation of medulla Norepinephrine - acts like agonist to epinephrine Stress - body state induced by a stressor (physical, chemical, physiological, infectious, emotional, social) Hypercortisolism ○ Primary (secrete cortisol by physician) ○ Secondary (secrete ACTH by tumor) - Cushing’s Disease Hypocortisolism ○ All adrenal steroid hormones - Addison’s Disease ○ Cortisol hyposecretion (secondary) - aldosterone production fine Thyroid [666-671] Thyroid gland - bilobed; endocrine tissue (follicular cells); targets all cells ○ T3 and T4 - tri/tetra-iodothyronine, calcitonin in C cells liver/kidney turn T4 to T3 (remove iodine) ○ Stores hormone in thyroglobulin molecule Increases basal metabolism/heat production/heart rate/GH Regulated by TSH, controlled by TRH Stimulates GH and IGF-I (insulin-esque GF) Graves’ disease - hyperthyroidism; TSI presence agonizes TSH, T4 decreases Goiter - enlarged thyroid gland due to excess TSH or TSI ○ Hypothyroidism - primary only; iodine deficiency → TSH force secretion, none  ○ Hyperthyroidism - excess TSH, tumor, excess TSI Parathyroid, Calcium/Phosphate [701-713] Parathyroid hormone (PTH), calcitonin, vitamin D control Ca2+ and phosphate ○ Calcium important for excitability, tight junctions, clotting, intercell comms PTH effects: ○ draws calcium (and phosphate) from bone, both fast and slow ○ conserves calcium and excretes phosphate in kidneys ○ indirectly promotes calcium and phosphate intestinal absorption PTH regulated by concentration of calcium Calcitonin (not important) lowers plasma calcium Vitamin D (cholecalciferol) → activates to calciferol/calcitriol (D3) by PTH Calcium and phosphate have inverse relationship in plasma concentration PTH hypersecretion: hypercalcemia → less excitable, bone thinning, kidney stones Vit D deficiency: less intestinal calcium → PTH removes more from bones to adjust Metabolism/Diabetes [685-701] Anabolism - synthesis of larger macromolecules; absorptive state; insulin Catabolism - breakdown of larger macromolecules; postabsorptive/fasting state; glucagon Metabolic/Anabolic processes ○ Glycogenesis - glucose → glycogen (liver and insulin) ○ Glycogenolysis - glycogen → glucose (glucagon and epinephrine) ○ Gluconeogenesis - amino acids → glucose (glucagon, epinephrine, cortisol) ○ Protein synthesis - amino acids → proteins ○ Protein degradation - proteins → amino acids ○ Lipogenesis - fatty acids/glycerol → triglycerides (adipose tissue and insulin) ○ Lipolysis - triglycerides → fatty acids/glycerol Brain must be supplied with glucose (via cortisol) Insulin stimulated by blood glucose/amino acids (from beta cells) Insulin excess → hypoglycemia to brain Glucagon antagonizes insulin (from alpha cells); increases during fasting state ○ Supported by ACTH, cortisol, GH, epinephrine (therefore insulin antagonists) Diabetes mellitus - hyperglycemia via lack of insulin/insensitivity to insulin ○ Excess glucagon can aggravate hyperglycemia Stress hormones (epinephrine/cortisol) cause metabolic responses GH causes anabolic responses Hypothalamus helps control glucose Broad Reproductive [716-723] Reproductive system does not help homeostasis  Reproduction - unions of male/female gametes Primary reproductive organs - gonads (testes and ovaries) ○ Produces gametogenesis (sperm and egg) vie meiosis ○ Secrete sex hormones (testosterone and estrogen/progesterone) Internal genitalia - accessory glands, ducts, organs In males, Wolffian ducts develop; in females, Mullerian ducts differentiate ○ Other duct degenerates ○ Determined by presence of anti-Mullerian hormone and DHT Secondary sex characteristics: body shape/hair, muscle, voice, libido Male Reproductive [723-731] Testosterone (androgen) effects: ○ Pre-birth reproductive system ○ Sex-tissues post birth + other reproductive effects ○ Secondary sexual characteristics (male hair, deep voice, thick skin, ‘manly’ body) ○ Anabolic action, bone growth in puberty, aggression? Testosterone secreted by Leydig cells in testes (+ 5a-reductase = DHT) Puberty - maturation of reproductive system ○ larger/mature gonads and reproductive tract ○ Secondary sexual characteristic developments (body shape) ○ Gamete production ○ Libido development Testosterone converts to estrogen via aromatase - same function, mostly Spermatogenesis - primordial germ cells to spermatozoa (1 to 16) Sertoli cells hold sperm like horses in horse race ○ Forms blood-testis barrier Testes controlled by LH and FSH (regulate testosterone and enhance spermatogenesis) ○ Both controlled by gnRH (pulsed secretion) - Gonadostat Theory ○ Testosterone negatively feedbacks LH - by kisspeptin → gnRH ○ Inhibin (secreted by sertoli cells) inhibits FSH ○ Activins enhance FSH, promote spermatogenesis gnRH activity increases at puberty, increasing LH and FSH secretion Female Reproductive [736-752] Formation of eggs (oogenesis) ○ Primary oocytes (2n) wait for ovulation ○ Oocyte surrounded by granulosa/thecal (follicular) cell - primordial follicle ○ Ovulation: primary meioses into secondary oocyte (paired, one polar body) Ovarian cycle alternates (interrupted by pregnancy): ○ Follicular phase - maturing follicles  Grows antrum (fluid cavity); used to eject oocyte ○ Luteal phase - presence of corpus luteum Ruptured follicle after ejection Follicular cells left behind for corpus luteum, hormone producer Secretes progesterone, estrogen, inhibin Corpus luteum soon degenerates (cycle over) In pregnancy, corpus luteum remains until birth ○ Controlled by estrogen follicles and corpus luteum (estrogen/progesterone) Depends on ovarian cycle, not GnRH Estrogen inhibits FSH and LH, until threshold (ovulation), then stimulates ○ Thecal cells produce androgens with LH (maintains corpus luteum) ○ Granulosa cells aromatase androgens to estrogen with FSH (makes antrum) ○ Ovulation - large LH surge once estrogen gets high enough (negative to positive) Also small FSH surge Halts estrogen synthesis Initiates meiosis Prostaglandin production Follicular cells → luteal cells Menstrual cycle - due to changing hormone levels in ovarian cycle ○ Grows myo/endometrium + gives estrogen-primed progesterone receptors Prepares for fertilization of ovum ○ Menstrual phase (period) - start of new cycle (luteal → follicular) Disintegrates endometrium (blood) Uterine prostaglandins vasoconstrictors (menstrual flow and cramps) ○ Proliferative phase (endometrium repairing itself) Estrogen stimulates endometrial growth (epithelial, glands, vessels) Ends at ovulation ○ secretory/progestational phase (corpus luteum formed) More progesterone/estrogen release due to corpus luteum Vascularizes and glycogen-filled due to progesterone (prep for pregnancy) Fertilization need capacitation (sperm can fertilize egg) ○ Fertilization in fallopian tubes, releases cortical granules to prevent polyspermy ○ Embryo develops blastocyst in uterus, forming placenta and villi from nutrients Placenta secretes hCG - keeps corpus luteum + pregnancy test hCS - lactation + maternal metabolism estrogen/progesterone - maintain endometrium ○ Replaces corpus luteum so it can degrade parturition/birth starts with labor ○ Relaxes cervix/pelvic ligaments via relaxin  ○ Positive feedback of oxytocin to contract to birth (+ placenta) Mammary glands ○ Develop breasts in puberty (estrogen) ○ Estrogen, GH, cortisol in pregnancy (develop glands more) ○ Progesterone (duct to secretory), PH decreases → PRL tells glands to milk Late pregnancy ○ Oxytocin induces breasts contraction (also returns uterus to normal) Similar pubertal changes to males (due to GnRH activity, kisspeptin/leptin): ○ larger/mature gonads and reproductive tract ○ Secondary sexual characteristic developments ○ Gamete production ○ Libido development Menopause (unique to females (like andropause)) - between 45-55 ○ Limited ovarian follicles → cease of menstrual cycles Central Nervous System [133-177; 284-286] Nervous System Organization ○ Central (CNS) - brain and spinal cord ○ Peripheral (PNS) - all other nerve fibers Afferent division - info to the CNS Efferent division - info from CNS to effector organs Somatic - skeletal muscles Autonomic - smooth/cardiac muscles, glands ○ Sympathetic & Parasympathetic ○ Enteric (ENS) - digestive tract nerve network Afferent neurons - receptors, peripheral axon, central axon Efferent neurons - CNS, efferent axon Interneurons connect afferent and efferent; 99% of neurons In CNS, 90% are glial/neuroglia - forms most tumors (gliomas) with meninges ○ Astrocytes - most abundant; hold neurons in place (glue); blood-brain barrier Store ions for action potentials Use gliotransmitters to affect synaptic transmission Clear toxic metabolic byproducts (glymphatic) ○ Oligodendrocytes - form myelin sheaths ○ Microglia - CNS immune system, can be affected by HIV/neurodegenerative ills ○ Ependymal - line fluid cavities of CNS; helps form new neurons in hippocampus Protections for brain: ○ Skull and vertebral column ○ Meninges - protective/nourishing membranes Layers (out→in): dura, arachnoid, pia mater/choroid plexus  ○ Floats in cerebrospinal fluid (CSF) Made in pia mater; absorbed in arachnoid villi ○ blood-brain barrier: 1 endothelial cell layer - mechanical, chemical, gated CNS Parts: autonomic control, emotions, movement, self-aware, thought/memory ○ Brain stem - breathing, circulation, digestion ○ Cerebellum (back-bottom) - balance, motor skills ○ Diencephalon (center) Hypothalamus - homeostatic control, emotion/behavior patterns Thalamus - senses, sensory relay station, consciousness, motor ○ Cerebrum (inhibition, purposeful movements, maintenance; top-front) Basal nuclei/cerebral cortex - movement, senses, cognition Cerebral cortex parts (back to front): ○ occipital lobes - visual input/processing ○ temporal lobes - auditory sensation ○ parietal lobes - processing touch ○ frontal lobes - voluntary movement, speaking, thought Other areas of brain: ○ Broca’s area - speaking; close to frontal lobe ○ Wernicke’s area - language comprehension; close to parietal, temporal, occipital Association areas: ○ prefrontal cortex - planning, decisions, creativity, personality ○ parietal occipital temporal cortex - complex processing (apple test), language ○ limbic association - motivation, emotion, memory (amygdala) Left and right hemispheres - logic vs. creativity (cerebral lateralization) Memory stages - consolidation (short→long) ○ Short-term: stored by transient synapse modifications Habituation - less response due to repeated stimulus Sensitization - higher response from small stimulus due to large stimulus Occur due to increase/decrease of Ca2+ influx Long-term potentiation - high neuron excitability due to repeated use Long-term depression - opposite of potentiation ○ Long-term: permanent changes/formation of synapses Memory trace storage (retention) ○ Hippocampus - declarative memory; facts and events ○ Cerebellum - procedural memory; motor skills ○ prefrontal cortex - working memory; executive function (problem solving) Cerebellum parts: ○ Vestibulo - balance/eye ○ Spino - muscle tone/skilled movement; management ○ Cerebero - planning and procedural memory  Brainstem and hypothalamus control sleep/consciousness ○ Medulla: swallowing/saliva, chemoreceptor trigger zone, breathing/BP ○ Pons: breathing/BP, analgesia ○ ECG measure brain waves Gamma: fastest, most common, high cognition Beta: high frequency, low amplitude, awake/focused Alpha: opposite of beta waves, awake/calm Theta: super alpha, really relaxed/slight sleep Delta: super theta, deep sleep ○ Sleep types: Slow-wave: cycling through slow waves Paradoxical: after slow-wave, ECG appears like awake; dreams Spinal cords ○ Horns Dorsal - interneurons, afferent end Ventral - efferent neurons Lateral - autonomic nerves ○ Reflexes - do not go to brain Afferent Division & Special Senses [181-224] Receptor types: ○ Photo - light ○ Mechano - movement ○ Thermo - heat/cold ○ Osmo - solute concentration ○ Chemo - specific chemicals ○ Noci - pain; damage — mechanical, thermal, polymodal Pain neurotransmitters - Substance P, glutamate Sensitized by prostaglandins (an eicosanoid) Fast pain: mechanical/thermal noci, myelinated A-fibers, localized Slow pain: polymodal noci, unmyelinated C-fibers, poorly localized Adaptation - lower depolarization in sustained stimulus ○ Tonic receptors, slow/none: useful for continuous information (proprioception) ○ Phasic receptors, fast; useful for changes in information (touch) Tactile receptors: type of mechano ○ Hair receptors - gentle touch ○ Merkel’s disc - slow light, sustained touch ○ Pacinian corpuscle - vibrations, deep pressure ○ Ruffini endings - deep pressure, skin stretch ○ Meissner’s corpuscle - rapid light, light touches  Visceral afferents - information from internal organs Sensory afferents - information from senses ○ Somatic sensation: body surface ○ Special senses: vision, hearing, equilibrium, taste, smell Acuity - how specific stimulus is responded ○ Determined by receptive field (smaller = higher); two-point discrimination ○ Determined by lateral inhibition - neurons inhibit others; only highest passes Brain has built-in analgesic system (pain suppressor) ○ Endogenous opioids (endorphins, enkephalins, dynorphin, morphine, opium) ○ Opioids bind to u opiate receptors, blocking presynaptic Substance P release ○ Also done with acupuncture analgesia Eye protections: eyelids, lacrimal glands (tears), eyelashes Eye layers (out → in) ○ sclera/cornea - white connective tissue/eye window ○ choroid/ciliary body/iris - blood vessels/lens+humor control/light allowance ○ Retina - photoreceptors (rods and cones) Eye interior - two fluid cavities, separated by lens ○ Aqueous humor - cornea → lens, lens/cornea nutrients, produced by ciliary body ○ Vitreous humor - lens → retina, keeps eye shape Light into eye depends on pupil/iris ○ Smaller w/ circular muscles; parasympathetic, myosis ○ Larger w/ radial muscles; sympathetic, mydriasis ○ Astigmatism - cornea curvature uneven Lens does not do work for distant light sources, only closeby (strengthens) ○ Accommodation - ciliary muscle changes lens shape/strength Relaxes → suspensory ligaments tighten → flat lens (symp) Flexes → suspensory ligaments loose → round lens (para) ○ Presbyopia - lens loses elasticity due to age Light retinal layers: ○ Photoreceptors (rods/cones) - hyperpolarize on light absorption Rods - 20x, periphery, night vision, gray, low acuity Cones (RGB) - 1x, central, day vision, color, high acuity In dark: passive sodium → calcium ion leak In light: no sodium → no calcium ion leak On-center cells: center excited by light, edge inhibited Off-center cells: center inhibited by light, edge excited Peripheral vision crosses sides (chiasm), central vision stays same side Visible spectrum of light - 400-700 nm Ear parts: ○ External and middle - sound waves → inner ear (amplified)  ○ Inner Cochlea - receptors for sound to nerve impulse Vestibular apparatus - sense of equilibrium Cochlea’s organ of Corti responsible for hearing ○ Sound propagates through perilymph fluid via oval window ○ Hair cells in basilar membrane bend with sound, releasing K+ Pitch differentiated due to length of inner hair cells High to low from start to end of inner ear Intensity differentiated due to amount of inner hair cell bending Deafness types: ○ Conductive - sound waves do not travel through external/middle ear well ○ Sensorineural - nerve signals are not made right from sound waves Vestibular apparatus parts: ○ Semicircular canals - three, hoop-shaped, oriented in axis, filled with endolymph Responsible for rotational acceleration of head (spinning) ○ Otolith organs - responsible for head position from gravity Utricle - responsible for vertical tilt and forward movement Saccule - responsible for horizontal tilt and vertical movement ○ Vestibular nuclei - integrates with info for balance, eye muscles, orientation Taste (Gustation) and Smell (Olfaction) ○ Tongue taste buds opens calcium channels, releasing serotonin/ATP ○ 5 tastes: salty, sour (ion channels); sweet, bitter, umami (secondary messengers) ○ Olfactory system needs water soluble vapor to smell ○ Olfactory system adapts quickly, can detect pheromones Efferent Division [233-248] Tone of Autonomic Nervous System ○ Parasympathetic - rest and digest; relaxation/housekeeping ○ Sympathetic - fight or flight; stress/only necessary actions Autonomic nerves are two neurons, pre and postganglionic ○ Parasympathetic - long pre, short post ○ Sympathetic - short pre, long post Parasympathetic cause of SLUDD: salivation, lacrimation, urination, defecation, death Important neurotransmitters ○ Acetylcholine (ACh) - secreted by all pre, para post ○ [Nor]Epinephrine ([N]E) - secreted by adrenal medulla for symp post Adrenal medulla - 80% E, 20% NE Important receptors ○ Cholinergic (binds with ACh) NicotinicN - between pre and post ganglionic/adrenal medulla fibers  Muscarinic - between para post and effector tissue ○ Adrenergic (binds with [N]E) a1 - excitatory; arteriolar smooth muscle (NE > E) a2 - inhibitory; always in gut (NE > E) B1 - excitatory; always in heart (NE = E) B2 - inhibitory; arteriolar smooth muscle, heart, skeletal (E) Varicosities - terminal end of a post-ganglion; releases neurotransmitter across large area Parasympathetic and sympathetic systems usually dually innervate organs; agonists ○ Exceptions (only sympathetic): Liver thermoregulatory sweat Adrenal medulla Blood vessels (arterioles/veins) ○ Exceptions (both stimulate): salivary glands (different saliva types) Origin of preganglionic fibers ○ Parasympathetic - cranial and sacral regions of spine ○ Sympathetic - thoracolumbar region of spine Skeletal Muscle Innervation: excitatory final common pathway using nicotinicM ○ Causes end-plate potential using ACh and opening of Na+ and K+ (like EPSP) Conditions affecting skeletal muscle innervation ○ Black widow toxin - increased ACh release (spastic → flaccid paralysis) ○ Botulism - blocks ACh release (flaccid paralysis) ○ Curare - blocks ACh receptors (flaccid paralysis) ○ Succinylcholine - similar to ACh (spastic → flaccid paralysis) ○ Organophosphates - inhibit AChE (spastic → flaccid paralysis) Spastic to flaccid paralysis cause: depolarization blockade (Na+ inactivation gate reset) Muscle Physiology [251-286] Muscle Categories ○ Striated (skeletal/cardiac) - dark bands ○ Nucleated (skeletal) - presence of multiple nuclei ○ Voluntary (skeletal) - innervated by somatic Every muscle fiber is electrically isolated from each other; finer control Myofibril Components ○ Titin (large) - largest protein; present throughout, rubber band ○ A (anisotropic) bands - stacked thick filaments with peripheral thin filaments ○ H zone - middle of A band; thin filaments absent ○ M line - center of H zone; holds thick filaments together ○ I (isotropic) band - thin filaments not in A band ○ Z line/disk - center of I band; between is sarcomere (contracts)  Thick filaments made of myosin: actin-binding and ATP-ase site (spun myosin heads) ○ Can form cross bridges - binding between thick and thin filaments ○ Has different energy states: high = ready to contract (at rest) Thin filaments made of: ○ Actin: spherical molecules; form helix shape, binding site for myosin ○ tropomyosin/troponin: bind to actin helix for contractions Tropomyosin - prevents myosin from binding to myosin Troponin - binds to tropomyosin, allowing myosin-actin binding Also binds to Ca2+ important for contractions Sliding filament mechanism - sarcomeres slide inwards towards unmoving A band ○ Power stroke - Ca2+ moves troponin/tropomyosin away (excitation-contraction) Allows myosin to bind to actin and bend, like oars (crawling) Happens many times per contraction Sarcoplasmic reticulum (SR) - modified ER, holds end lateral sacs of Ca2+ ○ Releases when action potential on A/I band junction (T tubule/plasma membrane) ○ ATP brings Ca2+ back to lateral sacs (active transport) - SerC, always working ○ Allows actin to bind to myosin heads ○ Rigor mortis - too much Ca2+, not enough ATP to detach Components of muscle tension ○ Contractile component - made by sarcomeres sliding ○ Series-elastic component - tendons pulling bones Origin - muscle connected to unmoving muscle Insertion - muscle connected to moving muscle Contraction types ○ Based on what is held constant Isotonic - constant load Isometric - constant muscle length Isokinetic - contraction velocity constant (velocity depends on load) ○ Based on how muscle changes Concentric - muscle shortens Eccentric - muscle lengthens Most muscle energy converted to heat, not work done (25:75) Lever action of muscle ○ Power arm - lever portion between muscle force and joint ○ Load arm - lever portion between joint and load force What affects strength of muscle contraction ○ Number of contracting muscle fibers Motor unit - motor neuron + all innervated muscle fibers Simultaneous motor unit stimulation - motor unit recruitment ○ Tension made by each contracting fiber; depends on:  Stimulation frequency (twitch summation) Fiber length (length-tension) How fatigued Fiber thickness Weak contraction (twitch) summation: small contractions add up, greater contraction ○ Results from sustained high Ca2+ levels & time for series-elastic component Caused by high frequency of action potentials ○ Tetanus (not the disease) - sustained strong contraction, no relaxation Optimal muscle length (l0): length at which maximum force achieved in a contraction ○ Length > l0: less myosin and actin interactions; less cross-bridging ○ Length < l0: less actin interactions, myosin pressed against Z line Less Ca2+ released, Ca2+ binds to troponin less Why muscle contraction/relaxation needs ATP ○ ATP binding for myosin-actin detachment ○ Myosin ATPase for power stroke ○ Ca2+ transport back to SR (SerC) ○ Na+-K+ pump to reset action potentials How muscle fibers make ATP (in order to what is used first) ○ Creatine phosphate: transfers an Pi to ADP; fastest (reestablished by O2) ○ Oxidative phosphorylation ○ Glycolysis - forms lactate → pyruvate Types of fatigue: ○ Muscle fatigue - muscle cannot respond to stimulation High levels of Pi, leakage of Ca2+, depleted glycogen reserves ○ Central fatigue - CNS does not activate enough motor neurons Discomfort, motivation loss, boredom, tired ○ Neuromuscular fatigue - problem with Nm receptors; rare Three types of skeletal muscle fibers (red = myoglobin; speed = twitch/Ca2+ movement): ○ Slow-oxidative (I) - low ATPase, fatigue-resistant, smaller, liver glycogen; red ○ Fast-oxidative (IIa) - mix between others, high ATPase; pink ○ Fast-glycolytic (IIx) - high ATPase, fatigable, larger, muscle glycogen; white Muscle atrophy (mass decrease): disuse, denervation, age-related (sarcopenia, 40) Motor activity types: ○ Reflex: simple, skeletal, autonomic; protective (withdrawal) and postural (stretch) Sources: proprioceptors, vestibular apparatus, touch, eyes Integration: spinal cord (withdrawal), brain stem (vestibular) ○ Voluntary: complex, goal-directed; muscle memory ○ Rhythmic: patterned movement (walking/chewing); central pattern generators Multiple neural inputs → motor unit output ○ Afferent neurons: interneurons in spinal cord  ○ Primary motor cortex/ corticospinal system: pyramidal cells; fine control ○ Brain stem/multi neuronal motor system: extrapyramidal; brain influences Posture and large muscles Muscle tone: overgoing, involuntary, low-level; important for stability Muscle receptors → skeletal muscle activity ○ Muscle spindles: has own efferent/afferent nerve supply; in muscle belly Detects length/change in length; non-contractile center Intrafusal fibers (gamma motor) inside extrafusal fibers (alpha motor) Gamma motor neuron innervates both sides of fiber Alpha-gamma coactivation: both neurons stimulate during contraction Helps intrafusal detection in rate of length change (tension change) ○ Stretch reflex (monosynaptic): works as local negative-feedback, no overstretch ○ Golgi tendon organs: in tendons; purely tension sensing (not part of reflex) Important for proprioception (externally/extrafusal applied tension) Smooth Muscle - small, unstriated; different structure depending on function ○ Thick myosin (longer than in skeletal), thin actin (no troponin) ○ Intermediate filaments (framework), no myofibrils/sarcomere pattern (no Z line) Dense bodies: more actin, acts as Z disc, held via intermediates ○ Arranged for squeezing, diagonals (crossover = dense body) ○ Activated via Ca2+ (mostly ECF) dependant myosin phosphorylation (chemical) ○ Phasic (burst contractions) and tonic (continuous contraction) ○ Develops tension despite relaxing when stretched (stress relaxation/rubber band) ○ Slow but efficient contractions for its job, long-term sustained contractions ○ Single-unit/visceral - found in viscera (hollow organs) Myogenic - self-excitable, either tonic or phasic Pacemaker - gradual depolarization from ion flux Slow-wave - spontaneous alternating polarizations Forms functional syncytium - contracts as unit ○ Multiunit - skeletal/smooth mix Neurogenic - stimulated by nerves, phasic Large blood vessels, small airways, eye muscles, goosebump muscle Cardiac Muscle - blends skeletal/smooth ○ Found only in the heart ○ Striated, length-tension relationship, pacemaker potentials/cells ○ Has intercalated discs (gap junctions), joined in branching network