Lecture 16/17 = renal system Flashcards

Question

glomerular filtration rate = GFR

Answer 1

total amount of filtrate formed per minute by both kidneys normal value = 125 ml/min depends on = total SA for filtration *large SA so get large amounts of filtrate formed continuously damage = less SA = less filtration filtration mb permeability more permeable = pass through easily damage = dec GFR net filtration pressure = GFR is directly proportional to NFP ( the pressure pushing fluid out of te glomerulus)

Answer 2

renal autoregulation (intrinisc) neural controls (extrensic) renin-angiotensin system (hormone - extrinsic) imp = stable filtration, proper urine formation, balance of fluids, ions and waste shared target = all reg the diameter of the afferent vessel Maintaining GFR ensures: Stable filtration of blood Proper urine formation Balance of fluids, electrolytes, and waste in the body

Answer 3

kidneys keeps GFR constant by det its own rate of flow and adjusting nephron blood flow ref diameter of afferent (little bit of efferent) more dramatic effect to reg aff. 2 controls myogenic mechanism tubuloglomerula feedback mechanism

Answer 4

focus = afferent responds to any change in bp of blood vessels, and how much smooth muscles in vessel contract when stretched when systemic bp inc = too much stretch = contricts = lessens flow low bp = not much stretch = dilates = opens up to improve flow

Answer 5

directed by macula dense cells of JGC = monitors salt content of filtrate + rate of flow if too fast = not enough salt is being absorbed = too much salt in filtrate = releases vasoconstrictors to slow things down if too slow = too much salt is absorbed = release less ATP

Answer 6

SNS has a role during extreme stress, overrides renal autoreg nad sends blood to heart brain and muscles direct sympathetic induced vasconstricition of afferent arterioles

Answer 7

activated by = direct stimulation of granular cells by SNS to secret renin = macula dense cells stim granular cells whey they sense reduced salt content and flow = reduced stretch of granular cells

Answer 8

generalized vasoconstrictor stimulates release of aldosterone = stems reabsorption of Na, water follows, inc blood volume, inc bp afferent arterioles have fewer receptors for angiotensin than efferent = has a bigger effect on efferent = blood comes in normal but leave slower so kindeys don't shut down.

Answer 9

substances moved against gradient, needs E, at level of basolateral mb (mb of filtrate not facing lumen). sodium pump actively pumps Na out of the tubule cell into the interdigital fluid now low conc of Na in tubule cell high conc of Na from tubule lumen wants to go to low conc in cell glucose, aa, lactate, vitamins, ions hitch a ride and get transported into the cell. passive but relies on active pumping of Na

Answer 10

most volume filtered by kidney doesn't become urine most things reabsorbed by moving through and not In bn cells (bc of tight junctions) glucose and aa = 100% reabsorbed active of passive deg of water/ions reabsorption = hormone adjusted.

Answer 11

carriers are specific to what they can carry but also has a limit, when all carriers are saturated, extra substance is not reabsorbed nad shows up in urine.

Answer 12

usually don't get filtered out but some my squeeze through get taken up by tubule cells from the lumen cells will hydrolyze it into aa and sent to the blood

Answer 13

first. T maximum is always constant no matter plasma conc 2nd. GFR will stay the same what to do. take plasma conc and multiple it by 1.25 = we get the amount filtered if amount filtered is less than transport maximum = all can be reabsorbed + non excreted if amount filtered is more than transport maximum = max of 375 will be reabsorbed = diff is excreted.

Answer 14

intracellular and paracellular routes transcellular= - across apical mb (from lumen to tubule cells) - through cytoplasm of tubule cell - across basolateral mb - into interstitial fluid and peritubular caps. for = Glucose, aa, ions, nutrients. paracellular = between adj tubule cells through tight junctions in intersisitual fluids to caps for = water nad ions esp = in PCT, where junctions are more leaky

Answer 15

diffusion, faciliated diffusion, omsosis along gradient no ATP = active reabsorption of Na pulls anions (esp Cl-) obligatory water reabsorption due to Na transport **not reg, in PCT and nephron loop due to structures and presence of aquporins as water leaves = makes gradient for reabsorption of other substances, esp if fat soluble

Answer 16

either no carriers, not lipid soluble, or too large N end products fo proteins and nucleic acid metabolism urea = mean N containing end product of metabolism. small enough to diffuse through pores half reclaimed creatinine = large , insoluble N waste molec. useful for measuring GFR uric acid = end product of purine metabolism = structure of DNA = some excreted some reabsorbed, too much = gout, arthritis, deposits in joints

Answer 17

PCT = all glucose and aa most ions, bicarbs and water loop of hole descending = water leaves (gets reabsorbed) ascending = salt leaves (gets reabsorbed) DCT and collecting ducts only a bit of salt and water stay absorption is reg by body's needs and hydration level

Answer 18

antidiuretic hormone = ADH open up water channels in collecting duct as it goes deeper in gradient renin-angio tenin system (+ aldosterone) = stim secretion of aldosterone = salt reabsorbed, water follows Atrial natriuretic peptide = ANP prod in atria of cell, protect from blood V or bp getting too high allows ot get rid of extra salt and water from kidneys

Answer 19

kidneys get rid of unwanted substances by 1. not reabsorbin them 2. secreting them into urine usually = H, K, creatinine, NH4, uric acid, urea mostly in PCT,some in late DCT and early collecting ducts

Answer 20

1. dispose of substances not in the original filtrate ( waste/drugs not dumped into filtrate in first place) 2. dispose of substances that were passively reabsorbed (get pushed back to tubule) 3. dispose of excess K ions 4. maintain blood ph, getting rid of excess H

Answer 21

countercurrent mechanism = Process that sets up the medullary gradient (via loops of Henle & vasa recta) Medullary osmotic gradient = The salty concentration difference in the medulla used to pull water out of urine

Answer 22

freely permeable to water, impermeable to solutes as filtrates moves down limb, water moves freely out by osmosis bc of the osmolarity of interstitial fluid. follows its conc of high to low. can reach 12000 most In juxtamedullay nephrons

Answer 23

impermeable to water actively transports NaCl out Na/K/2CL transporters move ions out but water can't follow = no transporters

Answer 24

descending limb = water follows grad out (high in cell to low in IF) tubule = becomes conc in ions ascending limb = ions get pumped to into IF set up gradient make it so that water can leave and conc. and loop continues.

Answer 25

reduce filtrate volume absorb as much water as possible

Answer 26

when over hydrated filtrate is dilute due to salt removal (too much water so water not reabsorbed but salts are actively pumped out. no ADH = collecting ducts remain impermeable and very dilute fine is produced (+ large volume)

Answer 27

when dehydrated ADH acts at collecting ducts = inc number of water channel in principal cells if don't want to lose more water in urine to maintain adeuqte bp facultative water reabsorption = reg based on body's need (hydration) + presence of ADH

Answer 28

enhances urinary output any substances that is not reabsorbed exceeds renal reabsorption ability ex. interferes w release of ADH = less aborption of water = peeing out more than drinking in caffein and diuretic drugs ion Na reabsorption , water can't follow the gradient (cuz its not formed) = water stays in tubule = lost In urine

Answer 29

volume of plasma from which a substance is 100% cleared per unit time ** a measure of how effectively the kidneys remove a substance from the blood and excrete it in the urine. RC = UV/P U = substance In urine V = flow rate or urine formation P = substance in plasma

Answer 30

U = 125 mg/ml P = 1 mg/ml V = 1 ml/min RC = (125 x 1)/1 RC = 125 thrfr = everything is staying In filtrate, excreted out of bodyi RC = 125 = GFR so its being filtered, not secreted not reabsorbed in the nephron = follows GFR

Answer 31

= 0 none is being excreted, like glucose and aa is higher than inulin, (higher than 120) = some is being secreted from blood to filtrate nad being excreted if lower than inulin (lower than 125) = some is being reabsorbed before being excreted

Answer 32

clear/pale to deep yellow urochorme = pigment from heme degradation deepness of yellow = conc pee cloudiness = infection, bacteria, UTI will develop ammonia our if left to stand bc of bacterial metabolism of urea affected by drugs and veggies also diseases usually ph = 6 acidic urine =diet rich in protein and whole wheat alkaline urine = diet rich in veggie

Answer 33

mostly water 5% solutes, in dec order = urea, Na, K, phosphate, sulphate, creatinine, uric acid much less levels of ca, mg, bicarb

Answer 34

detrusor muscles have to contract internal urethral sphincter must open follow by the external ""

Answer 35

about 200 ml's in bladder stretch receptor triggers reflex arc detrusor muscles contract + pulls internal sphincter open urine flows through internal sphincter into upper part of urethra like reflex arc = now one feels urge to go external sphincter under voluntary control = relax and fo = don't relax, ignore but feeling will come back as urine accumulates.

Answer 36

inability to control micturition voluntarily weakened pelvic floor muscles ex. pressure of pregnancy or NS problems

Answer 37

when urine leaks out during physical activities that inc abdo P. pushed down on outside of bladder + distracts you cough, vomit, laughing

Answer 38

bladder unable to expel urine

Answer 39

not enough functioning nephrons filtrate formation reduced or stopped nitrogenous waste accumulates = blood becomes acidic kidney not functioning = no EPO = anemia once functioning below 25% = dialysis

Answer 40

repeated damaging kidney infections physical injury to kindeys prolonges pressure on skeletal muscle **release of a lot of proteins and creatine phosphates, clog kindeys, esp if extensive damage to muscles (like being stuck under smth heavy for long) inadequate blood delivery to tubules.

Answer 41

blood is pumped outside of body to a machine, an artificial kidney, and then returned.

Answer 42

using the blood vessels of the peritoneal mb done at home/not at hospital a fluid -dialysate- is put into the cavity through a catheter, mostly sugar and salt encourages filtration through the peritoneum fluid and taste is drawn from the blood into the fluid which is then removed.

Answer 43

Intracellular fluid compartments = w/in cells 60% of total body fluids Extracellular fluid compartments = 2 areas 40% plasma = 20% of ECF intersistual fluid (IF) = 80% of ECF ** included under IF = lymphatic fluid, CSF, fluids of the eye, synovial fluid, GI secretions. there is a constant exchange.

Answer 44

electrolytes do bc they can dissociate to multiple particles Osmotic power = how much a solute can pull water The more particles in solution, the higher the osmotic pressure So electrolytes = more particles, = exert more pull on water = stronger osmotic power.

Answer 45

ECF cation = Na Anton = C ICF cation = K anion = Phosphate changes in solute conc in blood plasma will affect intracellular fluid volumes.

Answer 46

water intake must = water output intake = liquids, foods, cellular metabolism* ** = dehydration synth. as you join 2 aa to form a peptide = you form H2O output = most (60%) by kidney, fluid loss by lungs, sweat, skin, feces

Answer 47

less water = more solutes = more conc blood 1. thirsty = inc water intake 2. ADH = stimulates water reabsoprtion

Answer 48

too much blood = blood is dilute = thirst not stimulated ADH not stimulated/secretion

Answer 49

inc in plasma osmolality = blood becomes conc dry mouth (don't make saliva, conserve water) osmoreceptors of the hypothalamic thirst centre lose water to the hypertonic ECF (follow high to low gradient) receptors beocome irritable and depolarize = activate thirst centre = becomes aware you're thirst and pushes you to drink water dec in plasma volume = sensed as dec in bp = activates renin angiotensin mechanism = activates thirst centre once mouth becomes art = thirst feeling foes away = prevents over drinking

Answer 50

insensible water loss in lungs skin feces and urine

Answer 51

water follows salt if water channels are open 90-95% of ECF solute is Na + anion NaCl and NaHCO3 contribute majority Na determines blood plasma osmolaoty and blood volume Na content of the body can change but its conc in ECFC is monitors and remains stable

Answer 52

aldosterone ADH ANP other hormones cardiovascular baroreceptors

Answer 53

most influential factor acts slowly without aldosterone = 90% in filtrate is reabsorbed in PCT and loop high aldosterone = all remaining Na actively reabsorbed by DCT and collecting ducts. if we need that extra 10%

Answer 54

renin-angiotensin system = renin angiotensin mech stimulates adrenal cortex to release aldosterone which targets tubes. same thing for high K or low Na stimulates adrenal cortex to release aldosterone which effects the reabsorption and secretion of K Na/K pump. pump K into tubule (from tubule cell) as we pump Na out (into the blood)

Answer 55

decreased filtrate osmolality = drop in Na decreased stretch = drop in bp = drop In blood volume sympathetic NS

Answer 56

hyposecretion of aldosterone = loss of Na and water in urine autoimmune disease, destruction of cells in adrenal cortex resp for production of aldosterone nad cortisol both essential to life so go on hormone therapy

Answer 57

water reabsorption in collecting ducts relies on ADH secretion + will effect plasma Na conc. osmoreceptors in hypothalamus sense: low Na = excess fluid in blood at collecting ducts = we don't want extra reabsorption = no ADH released = no channels open pee is dilute high Na = low blood V/ not enough water = blood is conc = stimulates osmoreceptors in hypo to stimulate posterior pituitary to release ADH = works on collecting ducts of kidneys = opens channels = inc water reabsorption = less urine volume (as more water is reabsorbed into blood)

Answer 58

released in atria of heart when bp is elevated is a diuretic and natriuretic hormone = inc water excretion in urine = inc excretion of Na in urine 1. inh Na reabsortpion in DCT and collecting ducts 2. dec release of ADH, renin and aldosterone 3. induces vasodilation reduce blood volume to reduce bp

Answer 59

Estradiol: inc Na⁺ reabsorption = inc Na⁺ concentration (acts like aldosterone). Progesterone: dec Na⁺ reabsorption = inc Na excretion = dec Na⁺ concentration (blocks aldosterone) Cortisol: inc Na⁺ reabsorption = inc Na⁺ concentration (can mimic aldosterone at high levels).

Answer 60

a pressure sensor pressure diuresis = when blood V or P increases sympathetic output to kidney dec = dilation of afferent arterioles = inc GFR = more filtrate produced = more urine = loss of water and Na = volume nad bp comes back to normal

Answer 61

if conc of K is high in ECF = toxic we need to maintain mb potential in excitable cells and involved in acid/base balance within cells by moving in opposite direction of H if acidosis = too high H+ in blood, H go in, K leave to ECF = now deal w elevated K levels usually 10% in filtrate is lost but sometimes even that is more than the body needs so tubular secretion gets Na in exchange for excreting K.

Answer 62

same as for Na but in the opposite way. if inc K plasma levels = triggers release of aldosterone = inc levels of K secretion and absorb more Na so 2. 1. plasma K conc 2. aldosterone conc.

Answer 63

most of bodies Ca in bone, but imp for muscle contraction, release of NTs in neurons, and imp 2nd messenger for imp hormones in body so closely regulated

Answer 64

PTH = inc blood Ca calcitonin = decrease Ca level sin children by stimulating bone deposition and inh bone respiration

Answer 65

stimulus for secretion = drop in Ca levels 3 targets 1. bone = osteoclasts dissolve bone = fastest way to get Ca in blood 2. small intestine = stim activation of vit D to stimulate absorption of calcium from meal eaten 3. kidneys = inc Ca absorption, dec phosphate reabsorption. if we pull back both, wont be free Ca, will be stuck phosphate used for bones and tissues. free Ca = Nts release, muscle contraction. w

Answer 66

for activity functional protein depends on depends. 7.35-7.45 alkalosis = arterial blood ph higher 7.45 acidosis = arterial blood ph lower 7.35

Answer 67

breakdown of phosphorous containing proteins = phosphoric acid anaerobic metabolism of glucose = fermentation = lactic acid fat metabolism = fatty acids and ketone bodies loading and transport of CO2 as bicarb = makes H ions

Answer 68

chemical buffer system = carbonic acid to bicarb Na2HPO4 to Na2H2PO4 protein buffers resp centres in brain stem renal mechanism

Answer 69

biggest capacity but longest to kick in reabsorning or generating new bicard to get rid of H+ excreting bicarb = more more H+ in blood to bring pH back down

Answer 70

mid capacity, mid speed if H ions are accumulating, shift eqm to prof more CO2 t breathe more rapidly and deeply to get rid of accumulation. ie. getting getting H20 into water and out of blood

Answer 71

really fast but limited capacity carbonic to bicarb and H+ NaHPO4can soak up and extra H+ protein buffers = plasma w (-) charge can soak up H+ and buffer the changes in blood pH

Answer 72

key diff is the extent of dissociation ex. HCl = strong dissociation, in water, only exists as H+ and Cl- H2CO3 = carbonic acid = weak dissociation, in water, exists as H+ HCO3- and H2CO3

Answer 73

H+ secretion bicarb reabsoption

Answer 74

tubule and collecting ducts respond to pH and alter rate of H+ secretion secreted H+ comes from carbonic acid for each H+ actively secrets into the tubule lumen, one Na+ is reabsorbed = maintained balance H+ can combine with bicarb and product CO2 and water, CO2 returns to the tubule cells and promotes more H+ secretion bicarb moves into the caps with Na

Answer 75

problem = tubule cells almost completely impermeable to bicarb in filtrate solution = convert to CO2 to go in and reconvert to bicarb when in blood need to constantly replenish body's stores of bicarb = since breathing out CO2 which was initially bicarbonate in blood do it by reabsorbing it or making new ones in kidneys and move to blood Na follows

Answer 76

resorption recycles bicarb alr present and will get used up by the time you get to DCT + most H+ that you secrete in water molecules doesn't leave body since kindeys conserve most water. + new H+ enters with food so need new bicarb to maintain ph and send out H+ in urine

Answer 77

phosphate buffer system NH4 excretion

Answer 78

weak base is HPO4^(-2) usually 3/4 of phosphate is reabsorbed in acidosis = will leave more in lumen to be carried out of body done in type A intercalated cells of collecting duct. CO2 inside cell combines with water, makes carbonic, dissociates to H+ (goes to lumen) and bicarb (goes to blood) phosphate will soak up H+ ions to make H2PO4 = stay in filtrate Cl- enters cell for HCO3- leaving

Answer 79

starting point = the aa glutamine is deaminated, oxygenated nad acidified result = 2 ammonia and 2 bicarb into blood H in the ammonia go to filtrate

Answer 80

rare occurance type B = flipped type A cells = reabsorb H+ and excrete bicarb.

Answer 81

hypoventilation not getting rid of CO2 as quickly as you're making it more H+ bc of eqm reaction anything that interferes with lung functioning or ventilation = makes it harder to move air in/out of lungs blood becomes acidic

Answer 82

hyperventilation getting rid of CO2 faster than you're making it asthma, anxiety,

Answer 83

untreated diabetes or starvation= making a lot of ketone bodies diarrhea = loosing too much bicarb In GI tract kidneys problems or too much alcohol in system

Answer 84

vomiting = loosing too much acid = gets too basic too much Picard sever diuretics, or too much aldosterone

Answer 85

alkalosis = ph too high cause = resp = bc PCO2 is lower than it should be getting rid of CO2 faster than making it eqm shifts to make more CO2 using H and water = blood becomes basic compensating ? = no bc HCO3 levels are normal, aren't moving in opposite directions direction

Answer 86

alkalosis = ph too high is the cause resp? no, even if CO2 is high, if it were too high it would cause eqm to shift towards more H+ = make blood more acidic not basic, as we see here so cause = metabolic = inc in bicarb = push the eqm away from H+ = dec H+ = basic = alkalosis compensating? = yes bc CO2 levels are moving in opposite directions direction, trying to offset change in bicarb by holding on to more CO2

Answer 87

acidosis = ph is too low cause = respiratory CO2 levels are out of range, too high, pushing ram towards H+ = making more acidic compensating = yes bc bicarb is also high pushing eqm away from H+ + more bicarb = more buffering to soak up H+