psl 250 final comprehensive
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- realtionship between molecules, cells, and tissues.
- molecules are the assembly of atoms, cells are the basic unit of life made, and tissues are collections of similar cells with same local function
- what is the internal environment?
- interstitial fluid, liquid around cells
- what's negative feedback?
- event x causes a change away from set point and response y causes a return to set point ex: blood pressure
- what is the function of ribosomes?
- they make proteins for use in cytosol
- difference between rough and smooth e.r.
- rough- has ribosomes, site of protein synthesis, new proteins move through er to smooth er smooth- no ribosomes, fat/membrane synthesis, produces vesicles that carry new protein to golgi app.
- lysosomes...
- contain digestive enzymes, digest molecules down to usable size, ex: proteins to amino acids
- aerobic energy production..
- mitochondria,
- citric acid cycle...
- in mitochondrial matrix, 7 rxs, pyruvate/NAD/FAD go in, CO2/ATP/NADH/FADH2 comes out
- mitochondrial inner membrane...
- cytochromes form system on inner membrane
- oxidative phosphorylation...
- NADH donates electron to ETS, H+ follows, NAD recycled. As e- passes, ATP made at 3 cytochromes.
- what are vaults?
- octagonal barrel-shaped structures that may be involved in transport (of mRNA and ribosomes) from the nucleus to the cytoplasm
- what do microtubles do?
- cell stability/ transport along neurons, move vesicles, organelles and chromosomes
- hydrophillic vs. hydrophobic
- phillic- outer sides of membrane, don't cross by diffusion except H20 phobic- cross easily
- cholesterol?
- prevents close packing of fatty acid chains, create membrane fluidity
- difference between channels, carriers, and receptors
- channels- holes, only ions go thru, open or closed carriers- "revolving" proteins (no ATPase), alternative open side, molecules move w/ gradient or co-trans. w/ ion receptors- on outside, bind to solute, some activated by a physical change, activate either channel or enzyme
- difference between tight junctions, desmosomes, and gap junctions
- tj- water can pass thru, block movement between cells, create tissue sidedness, allows selective transport, must go thru cells d- cellular rivets, hold moving cells together gj- channels between cells, electrical signal from one cell activates next
- fick's law of diffusion
- rate of diffusion = permiablitiy x area x concentration gradient / molecular weight
- ion channels-
- different types for different ions, allows ion to move by chemical/ electrical gradients
- difference between facilitated diffusion, active transport, Na-K ATPase
- fd- no ATP used, move down diffusion gradient, molecules bind to one side and leaves on the other, high->low conc. at- pumps low->high conc., uses ATP, ions move by this na-k- creates ion gradient that produces all electric, moves Na out of cells and K in, electrical signaling
- secondary active transport
- hydrophillic, carrier has 2 binding sites: agonist and Na energy, cotransport or countertransport
- difference between concentration and permeability
- c- determine size of membrane in potential cells, differences in MP reflect differences in intracellular concentration p- determined by number of open channels, number of each open K or Na channels determines the MP
- diffence: depolarization & hyperpolarization
- d- MP is less negative, causes by K channels closing and Na channels opening, moves MP toward Na equilibrium potential h- MP gets more negative, caused by K channels opening and Na channels closing, MP moves toward K equilibrium potential (brain prevents signals from being sent)
- graded potentials...
- carries signal short distances, triggered by agosnists/physical force,don't send signals to brain, needed to reach threshold of action potentials
- voltage-gated channels...
- open when membrane reaches particular voltage, all v-gated channels open together causing action potential, inactivated soon after opening making refractory period
- ap spike
- all identical, Na enters and rapid depolarization to +20mV occurs, doesn't reach Na equilibrium potential b/c some v-gated K channels also open
- repolarization
- v-gated Na channels close after 1-2 msec, K channels still open and K leavs and membrane potential falls
- dendrites
- recieve neurotransmitter from other neurons, many branches, no action potential only graded.
- axons
- very long-carry AP away from cell body
- myelin
- accelerates rate at which axons are carried
- difference between hydrophillic/phobic hormones in regard to activation
- phillic- can't cross membrane, rely on membrane receptor activation phobic- diffuse past membrane into cell to activate genes
- refractory period
- after v-gated channels close they are unopenable for a time, no new APs during this time, AP only travel along axon in one direction (can't go back)
- presynaptic neuron
- end of axon, receive AP down axon, opens Ca channels
- vesicles
- contain neurotransmitter,increase in Ca triggers merger with cell membrane
- difference between EPSPs and IPSPs
- e-NT bins and Na channels open, Na enters and causes depol., one isn't enough to reach threshold i- K/Cl channels opened by NT, MP more negative, less likely to reach threshold
- difference between convergence and divergence
- con- multiple synapses into single neuron div-each axon has many synaptic knobs to other neurons, an AP in one neuron delivers NT to all its div. neurons at the same time.
- paracrines...
- local hormone, released from one cell, affects cell next door, important in control of blood flow
- phospholipids
- backbone of membrane
- what is the enzyme EVERYTHING has?
- Na-K ATPase
- what's the resting membrane potential?
- voltage across cell membrane when cell is NOT activated, determined by open ion channels
- second messengers
- activated by hydrophillic hormones
- cAMP
- activates kinases which cascades which amplifies signals
- g proteins
- regulate vesicle movement, cytoskeleton, growth, vision
- afferent vs efferent
- a- carry info into CNS e- carry info from CNS to body
- glial cells
- supports neural activity
- astrocytes
- control neural growth and blood vessel growth in brain
- cancer potential
- neural cells DON'T divide and can't form cancers but glial cells can
- plasticity
- when you learn something you alter number of synapses you have
- electroencephalogam
- used for death determination.
- basal nuclei
- controls balance, postural control is non-conscious
- thalamus
- receives sensory input from opposite side, directs and edits input to cerebral cortex
- limbic system
- detects emotions and memory formation
- emotions
- few connections to cortex-limited cortical control of emotion, can't make emotions just go away
- difference between short term/long term/ and working memory
- st-hippocampus, alter activity in existing neurons lt-temporal, creation of new synapses and memory traces, makes copies of important memories over years w-frontal lobe, comparing new experiences to old recalls to determine relevance
- cerebellum (balance/coordination)
- controls coordinated/learned movements -maintains balance and controls eye movement -afferent input gives current muscle positions, as practice occurs, motor cortex/parietal lobe/cerebellum take over
- slow wave sleep vs. REM (paradoxical sleep)
- slow wave before REM sw- 4 stages rem-new synaptic contacts made increase long term memory
- reflex/ components of reflex arch
- r-neural response w/o conscious input ra- effectors are muscles and glands
- stretch reflex
- fastest b/c afferent neuron synapses directly with efferent
- difference between physical and chemical receptors
- p-changes open ion channels, changes MP c- taste, smell, chemical binds receptors/opens channels/changes MP
- adaptation
- dcreases AP # despite prolonged stimulus
- difference: phasic/tonic receptors
- p- adapt over time t- don't adapt (few tonic receptors)
- difference: fast/slow pain
- f- sharp, localized, passes quickly. myelinated affarents- glutamate NT s- diffuse, dull, long lasting. unmyelinated afferents- substance P NT
- enkephalins/endorphins
- bind to opioid receptors, short time course, block pain pathways
- taste receptors
- salty- Na sweet- organic sturctures acid,sour- H bitter,bases-cations, poisons, most sensitive receptor umami- glutamate (MSG)
- olfactory adaptation
- in CNS- brain can overcome adaptation
- lens-ciliary body
- lens refracts light to focus on retina, ciliary body has muscles parallel to lens that focuses
- aqueous humor
- glaucoma: decrease drainage or excess production increases pressure causing retinal damage
- photoreceptors
- rods- shades of grey cones- color receptors (fewer) both converge on bipolar cell
- bipolar cells
- activated by rods/cones, no APs-synapse w/ ganglion cells, edge effect
- ganglion cells
- reach threshold and fire APs that leave eye for CNS, carry visual info to lateral geniculate
- presbyopia
- hardening of lens, reduces rounding of lens for near vision
- color vision
- 3 different opsins with retinene (yellow,green,blue)
- ear bones
- malleus (hammer), incus (anvil), stapes (stirrup), vaces waves to oval window
- middle ear
- amplifies sound 20x
- eustachian tube
- drains middle ear fluid
- basilar membrane, hair cells, tectorial membrane
- bm- vibrates to sound waves shape hc-rest on basilar mem. airs imbedded in tectorial mem. tm- when bm vibrates imbedded hairs pulled on, hair cells produce GP->NT to afferent neurons, APs to CNS by auditory nerve
- timbre (pronounced tambur)
- overtones that allow source distinction
- rotational acceleration
- as fluid lags in motion, fluid pulls on hair cells
- semicircular canals
- reequilibrates when hard rotation stops
- fight or flight response
- designed to remove danger, increase blood flow to skeletal muscle and heart
- receptor types (alpha/beta/beta2)
- a- cause increase in tissue activity (fast) b-increase Ca in heart and increase heart activity b2-bronchiole constriction
- parasympathetic responses
- decrease heart rate, increase GI contractions/secretions, increase pancreatic secretions, contracts urinary bladder, relaxes internal anal and urinary sphincters
- acetylcholine release, endplate potential, AchE
- ar-ach binds to receptors on muscle membrane ep- larger than EPSP AchE- removes Ach
- sarcomere
- functional unit of contraction
- components of thick/thin filaments
- thin- actin polymer backbone, tropomyosin, troponin thick- myosin polymer
- troponin-Ca binding
- Ca binds to troponin on thin filament
- tropomyosin shift
- how skeletal/cardiac muscle are activated
- diff. between force generation and filament sliding
- fg- caused by loss of P fs- minimizes energy
- motor unit
- motor neuron and muscle fibers it innervates, activates all fibers in a motor unit
- twitch vs tetanus
- tw- single muscle activation te-summation of twitches
- force-velocity relation/inverse relation
- fr-heavy loads moved slowly, light loads moved quickly ir-high force = low velocity, vice versa
- times of phophocreatine, flycolysis, oxidative phosphorilation
- p- supports 20 seconds of full activity g- 2 mins op- 2 hours
- hypertrophy/ filament number
- change as function of activity
- nuclear bag fibers/dynamic response vs. nuclear chain fibers/static response
- nbf-tells change in length dr-detect change in length ncf-tells length sr-detects fiber length
- gamma motor fibers
- contract muscle portions of intrafusal fibers
- dense bodies
- analogs of the z line and sarcomere
- tone
- activation of smooth muscle with no stimulus
- myosin light chain kinase
- enzyme that activates smooth muscle
- latch
- maintains force with little energy use
- visceral SM vs. Multi-unit SM
- v-one contracts, all contract/ gap junctions m-each cell individually active/ no gap junctions or APs
- intercalated disks
- desmosomes for strenght, gap junctions for electrical activation spread
- SA node
- where heartbeat is initiated
- ventricular muscle
- sodium dominated
- electrocardiogram
- sum of changes in cardiac APs
- P wave/QRS complex/T wave
- p- atrial depol. qrs-ventricular depol. t- ventricular repol.
- ventricular systole and aortic pressures affect
- vs- contraction of ventricles ap- determine load on on heart
- heart rate dependence
- if heart rate gets too high perfusion of coronary system goes down and heart doesn't deliver blood efficiently
- cardiac output
- product of stroke volume x heartrate, amount of blood pumped per minute
- effect of neural influences
- para-slow heart down symp-speed heart up
- vessel radius
- most important variable factor controlling flow thru vessel
- viscosity
- determined by number of RBCs
- coronary circulation
- heart rate dependent
- alcohol effect on atherosclerosis
- dissolves fatty streak in stage one
- capillary flud exchange and filtration/reabsorption
- -balance of BP forcing fluid out and osmotic presure from plasma proteins drawing fluid in f-at high pressure end r-at vesous end with lower pressure
- lymph flow and edema
- lf-return of filtered fluid e- excess filtration causing swelling
- venous valves
- prevent backflow, help blood from lower body get back to heart
- metabolic vasodilators
- more active = more bloodflow
- enothelial factors/ nitric oxide
- ef- paracrines no- hormonal/neural activation
- baroreceptors
- stretch receptors
- control of vasoconstriction and dilation/ resetting
- c-short-term control of BP r-body adjusts to own normal BP
- cardiac effects
- hurts heart if BP too high, hypertrophy
- diuretics/ACE inhibitors
- d-increase Na excretion/lowers blood volume/decreases BP a-boock conversion of angiotensin I to II
- plasma proteins
- albumin, globulins, fibringogen
- Erythrocytes
- RBCs, lose cholesterol and rupture in tightest capillaries after 120 days
- hemoglobin
- 4 protein chains can carry 4 O2 molecules, 1/chain
- platelets/ activation
- pinched off parts of megakaryocytes in bone marrow a-by collagen and other proteins in connective tissue of blood vessels
- coagulation
- blood-clottting
- intrisic/extrinsic system
- i- in plasma, collagen activates cascade e- thromboplastin starts cascade
- clot removal
- activation of plasmin
- neutrophils
- rapid response/ diapedesis
- monocytes
- convert into macrophages by moving into tissue
- eosinophils
- produce acids that kill parasites and allergic response
- complement system (activation/pore formation)
- major bacteria killer a- by antibodies or protein properdin pf- c5-c9 forms pores in membrane
- histamine
- increases blood flows and capillary permeability
- interferon
- activates anti-viral defenses in cells near virus infected cells
- antigen presentation
- part of antigen linked to MHC protein and put into cell membrane
- plasma cell vs. memory cell
- p-limited lifetime (1 week), make antibodies m-few cells have long life, provide antigen immunity
- primary response vs. secondary response
- p- activation of b cells slow short and weak s- activation of memory cells is fast strong and long
- antibody functions
- major- activate complement system to kill bacteria, labels cells for ingestion by phagocytes, activate natural killer cells
- cytoxic t cells vs. helper t cells
- c- bind to cell and inject perforin to form pores and cause osmotic lysis h- release cytokines that activate all b and t lymphocytes
- MHC class I/II
- 1- self-antigens on surface of cells/identify cells as self 2-ingest and present antigens/activate t cells
- epidermis/dermis/hypodermis
- e-desmosomes and keratin fibers hold cells together, prevents evaporation d- regulates heat loss, increase touch sensitivity, absorbs UV h- insulates body from heat loss
- type I/II cells
- 1-separate air from interstitial fluid 2- produce surfactant to decrease resistance to alveolar opening
- boyle's law
- pressure x volume = constant, controls breathing
- inspiration
- caused by contractions of diaphragm
- alveolar surface tension and how surfactant breaks it up
- a- adherence of water molecules creates surface tension on inside of alveoli s- several phospholipids mix w/ water and decrease surface tension
- anatomical dead space
- normal tidal volume is 500 ml (150 of mouth, pharynx, trachea, bronchi, bronchioles. 350 is normal alveolar inflation)
- composition of alveolar air
- P02 = 100mmHg, PC02 = 40
- diffusion acroos alveolar wall
- oxygen moving into blood, carbon dioxide moving out
- Oxygen transport (oxygen-hemoglobin binding)
- ot- 1.5% carried by dissolved O2, 98.5% carried by binding to hemoglobin oh- sigmoidal curve- cooperativity between 4 Hb subunits
- carbon monoxide affects
- binds to Hb, shifts Hb-02 curve to left
- carbon dioxide transport
- 10% dissolved, 30% bound to plasma protein and Hb, 60% converted to bicarbonate
- medullary control centers
- dorsal/ventral respiratory groups. initate normal breathing and increases inspiration/expiration
- chemical control of respiration
- CO2 controlled
- emphysema (decreased alpha-antitrypsin, surface area)
- e- cigarette smoke, coal tar are most common causes d-protects lung tissue from digestion sa- progressive decrease in sa, need pure O2 to fill Hb
- cystic fibrosis
- recessive gene, decreased Cl channel activity, loss of airway Na and water, mucus sticky and digestive enzymes increase
- nephron
- functional unit of kidney
- vascular/tubular system
- v- 2 capillary systems, 1 for filtering, 1 for reabsorption t- from bowmans capsule to ureter
- glomerular filtration
- from glomerulus into bowmans capsule,only cells and proteins not filtered
- tubular reabsorption
- must recover most filtrate (125 filtered, 124 ml/min reab. = 2 ml/min urine = 2.88 L/day)
- glucosuria
- if glucose in urine, blood must have 3x amount normal glucose
- sodium reabsorption
- controls reabsorption of many other molecules
- renin-angiotensin system (production/effects)
- r-maintain BP by increasing Na and water reabsorption p- already know e- powerful vasoconstrictor, releases aldosterone
- tubular secretion
- 3 process in kidneys, extra removal from plasma, move material into filtrate
- H secretion vs. K secretion
- increase in secretion of one decreases secretion of the other
- vasopressin/ aquaporins
- v- causes insertion of aquaporins in CD membrane a- H2O channels, retain H2O
- urine buffering
- filtrate pH must be 4.5 or greater for H to enter filtrate, urine buffered by bicarbonate/phosphate/ammonia
- aldosterone
- increases number of active Na carriers on lumenal side of CD tubular cells
- bladder sphincter
- internal- smooth muscle, involuntary external- skeletal muscle, voluntary
- ICF vs. ECF
- i- 2/3 total body water, K dominated w/ protein e- 1/3, Na dominated, no protein
- BP control/ salt intake
- b- short term drop in pressure causes auto-transfusion, long term is balance of thirst/intake and kidney fluid action s- kidneys need .5g NaCl/day, pee out extra
- ECF osmolarity control vs. tonicity
- ecf- needed to prevent swelling/shrinking of cells t- behavior of cells in solution
- hypertonicity
- -cells shrink in hypertonic solution
- acidosis effects
- causes neural problems
- control of H (extra cellular buffer)
- e-bicarbonate most important buffer
- repiratory control of H
- second line of H defense, works with non-respiratory source of H, reduces CO2 in blood, reducing H back toward normal
- repiratory/metabolic acidosis
- r- abnormal CO2 retention from hypoventilation, renal compensation by increased H secretion m- most common acid-base disorder, excess H production durin fat use in diabetics, exercise leading to lactic acid and H production
- complex carbohydrates
- must be broken down by enzymes to be absorbable monosaccharides
- lactose intolerance
- no lactose produced = no digestion of lactose
- protein digestion (proenzymes)
- pd- must be broken down into amino acids p- released in protective form as to not harm pancreas
- infant protein absorption
- absorb protein directly
- micelles/absorption/portal vein
- m- help absorption of fats, carry fats to brush border a- MG and FFA cross and reform into TG in mucosal cells pv- transports water soluble foods directly to liver
- potassium absorption
- most critical to not have any neural problems
- vitamin travel
- B and C- portal vein. A,D,E,K fat soluble-micelles-lymph
- basic electrical rhythm
- function of SI.
- migrating motility complex
- clears small intestine at end of meal
- gastrin/secretin
- g- initiates mass movement in LI that triggers defecation s- neutralizes stomach acid in duodenum
- mouth secretions
- bicarbonate, H2O, amylase, lipase, mucus, lysosome anti-bacterial enzyme
- reflux
- incomplete closure of lower esophogeal sphincter, acid irritates esophagus
- stomach secretions
- pepsinogen, HCl, mucus, gastrin
- stomach emptying
- pyloric sphincter secretes chyme in small amounts
- exocrine pancreas
- produces bicarbonate solution and enzymes for digestion
- alkaline secretion
- high bicarbonate conc.
- enzymatic secretions
- different enzymes for digestion
- bilirubin metabolism
- major waste product in feces and urine, breakdown product of heme
- gall bladder function
- stores bile between meals and delivers it when CCK comes along
- microvilli vs. villi
- mv- folds of cell membrane v- folds of SI wall tissue
- SI motility
- segmentation of mixing contractions and circular smooth muscle
- diarrhea
- loss of H2O and K, usually from LI
- gastroileal reflex
- emptying from small to large intestine when new meal comes
- defecation
- almost identical to urination, gastrin triggers colonic contraction
- Basal metabolic rate
- 2000 calories/day
- hypothalamic control of intake
- matching feeding to energy needs, balance of hunger and satiety
- Neuropeptide Y/ melanocortins
- released by HT, stimulate appetite m- realeased by HT, suppress appetite
- leptins
- increasing fat storage signals satiety by releasing leptins
- heat exhange
- radiation, conduction, convection
- response to cold/heat
- c- decreased skin bloodflow, human adaptation h- increased skin blood flow, increased sweating
- diurnal/circadian secretion
- day/night around a day rhythms- on a 24 hour cycle
- down regulation/permissiveness/synergism/antagonism
- d-desensitization p-one hormone enhances response of second s- two hormones increase each others activity a- one hormone reduces the effect of another
- plasma calcium
- 99% Ca stored in bone
- parathyroid hormone
- increases reabsorption of Ca, necessary for life
- hypocalcemia
- low blood Ca, larynx and diaphragm spasms- no air