urinary Flashcards

Question

is gluc excreted

Answer 1

normally no bc all reabsorbed, only if renal threshold reached if overwhelming amount gluc = gluc in filtrate = glucosuria

Answer 2

Na+ co-transport BUT hormonally regged by parathyroid hormone * PTH reduces reabsorp = incr excretion

Answer 3

* large SA * single layer epithelial cells * high conc Na+K+ATPase * high conc carbonic anhydrase * peritubular caps high oncotic press (bc just lost loads fluid in corpuscle

Answer 4

= readily cross mems so as fluid -> blood also -> blood down conc grad = hard excrete | this is why liver converts many foreign substances -> water sol = detoxi

Answer 5

always active - substances must be ionised to pump across mem thru channs

Answer 6

1. 2AT Na+H+ exchanger apical mem * some bind non-bicarb buffers + excreted in urine 2. 2AT NH4+ Na+ antiporter apical mem * from aas combined w H+ make NH4+ | all unregged

Answer 7

no prot carrier apical mem = impermeable to bicarb * reabsorp linked to H+ secr * need lots carbonic anhydrase enz bc bicarb super important buffer in bod + don't want to lose H+ + HCO3- AT = = v lil change urine pH | if H+ in lumen binds non-bicarb buffer then secreted in urine

Answer 8

*ionised* organic acids/bases * e.g. prot-bound organic mols - hormones, drugs, environ pollutants non-specific organic anion/cation transporters

Answer 9

* 100% gluc + aas * 70% water, Na+, K+ * 80-90% HCO3- * other ions + stuff variable

Answer 10

1. mostly same along PCT bc loads solutes etc out but also loads water out 2. DCT = decr vol + diff composition to prot free plasma 3. urine output varies in vol + osmolarity

Answer 11

osmolarity incr as go into medulla from that of prot free plasma (ISF becomes more hyperosmotic) * determines limits for urine osmolarity + conc * varies specied to species

Answer 12

relative length LoH + no. juxta medullary nephrons

Answer 13

need conc grad to move water by osmosis against

Answer 14

1. descending no ion pumps but lots aquaporins (v permeable water) 2. all ascending impermeable to water (= no solvent drag) 3. AT ions out thick ascending = osmosis water out descending -> ISF (bc ISF hyperosmotic) 4. water out = incr conc filtrate 5. fluid flow = higher osmolarity further down tube = more extreme = osmotic grad multiplies down tube | controls conc urine by expression aquaporins

Answer 15

= vasa recta (specialised peritubular caps) to supply O2, nutrients -> medulla * parallel to limbs LoH * blood flows opp direction to filtrate * hairpin loop slows Robloodflow

Answer 16

as down takes solutes (= more concd), as up takes water (less concd) - free exchange blood + ISF * accentuates conc diff bet cortex + medulla

Answer 17

if normal cap bed exchange blood + ISF fuck up osmotic grad

Answer 18

N waste urea freely filtered = incr conc in filtrate bc less water (v high in collecting duct) * urea channs in medulla allow CD -> ISF -> recaptured in descending LoH incr osmolarity in medulla (hyperosmotic ISF) = incr conc grad

Answer 19

upregs urea channs in CD = more passive flow -> ISF + descending LoH

Answer 20

antidiuretic hormone released posterior pituitary: 1. made + packaged in neuron 2. vesicles transported down cell 3. stored posterior pituitary 4. released into blood -> circulate

Answer 21

1. ADH binds specific mem receptor on sensitive principal cells in CD 2. activates cAMP 2nd messenger sys 3. cell inserts aquaporins apical mem 4. water osmosis -> blood (can't AT water) | endocrine control water balance

Answer 22

Na = 100% filtered, 70% reabsorb in PCT, 20% in LoH K = 100% filtered, 70% reabsorb PCT, 30% in LoH

Answer 23

* Na+K+ATPase on basolateral mem maintains grads * leak channs on apical mem = passive diffusion bet filtrate + principal cells

Answer 24

1. DCT/CD vs PCT 2. both have asymmetrical arrangement Na+K+ATPase 3. no microvilli principal bc lower vol 4. principal cells impermeable to water w/o ADH = doesn't always follow Na+ but does in PCT 5. principal responsive ADH + aldosterone

Answer 25

1. incr activity channs + pumps (K+Na+ATPase, leak channs) 2. synth new channs + pumps intracellular receptor to upreg movement K+ + Na+ - important K+ homeostasis = incr reabsorp Na+ = more water reabsorp osmosis incr blood vol incr SV but decr [K+] in blood (also stimmed incr [K+] | fat sol hormone = can enter cell easy

Answer 26

* 100% freely filtered * reabsorp PCT Na+ co-transport hormonal control * no reabsorp DCT/CD * dietary excess excreted (lots)

Answer 27

* 50% bound albumin so only 50% freely filtered * 70% reabsorb PCT * selective reabsorp in DCT/CD hormonal control (PTH incr reabsorp) * relatively small amount excreted

Answer 28

released in response decr [Ca2+] in blood - decr reabsorp P in PCT, incr Ca2+ in LoH, DCT, CD

Answer 29

DCT = cleaner edges bc no microvilli

Answer 30

CD = cuboidal epithelium

Answer 31

K + HCO3- bbut homeostatic mechs can lead secr back -> filtrate

Answer 32

incr = higher, decr = lower, by incr/decr glomerular cap press (regged by afferent/efferent arterioles)

Answer 33

too high: too much filtrate, incr urine (sys no keep up). incr flow rate = no time reabsorp + stuff lost in urine too low: too little filtrate = decr flow = some waste has time reabsorb, accumulate in bod, not excreted | v important + has be protected

Answer 34

bp up + down w exercise etc but want GFR constant - would damage caps + nephrons + mess up balance in blood * so afferent arteriole constricts (GFR decr)/dilates (incr) | can't rectify extreme bp or prolonged - small/moderate changes bp

Answer 35

1. myogenic response - to change in afferent bp 2. tubuloglomerular feedback - to change in [Na] in LoH, reps filtrate vol

Answer 36

stretch-sensitive musc cells detect incr bp = vasoconstrict vascular myocytes afferent arteriole = decr blood flow, decr HP, prevent GFR incr | + vice versa, v fast bc change where detection

Answer 37

ascending LoH runs bet afferent + efferent bvs + adjacent cells in walls modified form JMA = specialised cels for detection * arteriole cells -> juxtaglomerular cells * tubule cells -> macula densa

Answer 38

JGA = dense grp cells

Answer 39

1. macula densa cells detect changes [Na] + so fluid vol 2. send paracrine signals to adjacent sm myocytes in afferent arteriole 3. = vasoconstr/dil macula densa also stim release renin from JG cells for RAAS | slower, indirect response, detecting incr/decr in GFR

Answer 40

1. adrenal cortex -> aldosterone -> Na reabsorb 2. pit gland -> ADH 3. arterioles vasoconstruct incr TPR 4. CV centre medulla oblongata incr symp (incr CO) 5. hypothalamus incr thirst + ADH all incr bp (some via incr plasma vol) | overrides autoreg of GFR

Answer 41

plasma [K+] directly detected in adrenal cortex for neg feedback in release aldosterone asw as RAAS

Answer 42

1. decr bp directly -> JGCs afferent arteriole 2. decr bp -> decr GFR -> macula densa -> stim 3. decr bp -> CV control centre -> incr symp -> JCGs secr

Answer 43

1. constrict afferent arteriole = decr blood flow to glom caps = decr HP = decr GFR 2. relatively greater constr efferent = incr HP = preserve GFR (relatively small decr) * = HP peritubular caps decr, promoting tubular reabsorp = normalise bp | w/o protective mech 2 GFR fall lots = renal function compromised

Answer 44

natriuretic peptides decr bp + incr GFR (less time reabsorp) * afferent arterioles vasodil * adrenal cortex decr aldosterone secr * nephron decr Na + water reabsorp * hypothalamus decr ADH secr * medulla oblongata CV centre to decr bp

Answer 45

urine composition stays same bet CD + bladder, except in horse where glands secr mucous (= viscous urine)

Answer 46

1. detrusor musc - sm of bladder wall, controlled ANS 2. internal urethral sphincter - sm @ exit bladder -> urethra, controlled ANS 3. external urethral sphincter - sk, controlled somatic NS (conscious control, prevent emptying even when ANS attempts urine discharge)

Answer 47

symp = detrusor relax (bladder fill) + internal contract (close sphincter) parasymp = detrusor contract (eject urine)

Answer 48

symp: noradrenaline acting on β2 receptors on detrusor + α1 receptors on internal sphincter somatic: Ach acting on nicotinic receptors to excite external sphincter musc for contraction

Answer 49

1. filling sufficient to stretch sm musc = myogenic reflex contraction detrusor 2. sensory nerves carry info -> spinal cord for: 3. activation parasymp motor nerves contract detrusor 4. = passive press induced relaxation internal sphincter 5. also inhibit somatic motor drive to external sphincter

Answer 50

parasymp: Ach on muscarinic for contraction detrusor somatic: inhibition Ach acting on nicotinic to inhibit contraction

Answer 51

1. hypogastric = symp to detrusor + internal sphincter 2. pelvic = parasymp to detrusor 3. pudendal = somatic to external sphincter hypogastric from L1-L2 on spinal cord pelvic + pudendal from S1-S2

Answer 52

from interstitial cells kidney to stim erythropoiesis (production rbcs) * regged by O2 levels in tiss | neg feedback from hypoxia -> Epo -> normoxia -> less Epo

Answer 53

hypoxia = Epo proded = spongy bone stimmed release more rbcs = incr rbcs = incr O2 supply :)

Answer 54

* ingested most foods + not stored * [K+] in ECF relatively low + important maintaining mem pot

Answer 55

high [K+] in ECF = decr movement K+ out = mem pot less polarised + less neg = cell more excitable - esp problem for musc cells

Answer 56

100% filtered, 100% reabsorbed in PCT + LoH * plasma conc regged by secr -> filtrate in DCT + CD * aldosterone stims principal cells secr more in filtrate * reg bp trumps reg K+

Answer 57

equiv to clearance drug w known amount in plasma if: * drug freely filteres * not metabed * not absorbed/secr * excreted unchanged in urine ideally use continual infusion plant polypeptide inulin but not practical so look at conc N waste products in blood

Answer 58

N waste product from degradation creatine phosphate * synthed at continual steady rate * freely filtered w no reabsorp or secr so urine output good measure GFR (measure it in blood plasma) GFR decr = less creatinine excr (bc blood moving at same rate so less out -> filtrate = accumulates in plasma = higher reading

Answer 59

main N waste product in animals + freely filtered * water soluble + so small also partially fat soluble = some reabsorb down conc grad w/o transporters * normally 50% reabsorbed but GFR decr = more time reabsorp = incr conc blood (where measure) | synthed liver so liver disease can affect result also less reliable

Answer 60

incr nitrogenous waste products in blood * urea + creatinine incr above normal levels animal = azotaemic azotaemia = meausre decr GFR

Answer 61

* freely filtered * 80-90% reabsorbed PCT * 10-20% reabsorbed LoH

Answer 62

* freely filtered * unregged secr -> PCT via secr NH4+ (2AT) * unregged secr -> PCT via secr H+ 1. captured bicarb buffers + recycled for bicarb reabsorp 2. captured non-bicarb buffers = urinary secr | intercalated cells allow reg H+ secr + synth bicarb

Answer 63

1. H+ ATPase for H+ -> filtrate (DCT) 2. H+K+ATPase for H+ -> urine exchange for K+

Answer 64

active response to incr [H+] in interstitial space (acidosis) - get rid H+, make HCO3- | in DCT

Answer 65

pH homeostasis prioritised over K+ homeostasis (retains K+ to get rid H+) = can lead hyperkalaemia

Answer 66

active response decr [H+] in intersititial space (alkalosis) = absorb new H+ | DCT ## Footnote CA = carbonic acid

Answer 67

1. H+ATPase vs Na+H+ antiport 2. HCO3-Cl- exchanger vs Na+HCO3- symport (basolateral mem) 3. PCT: prot secr = net bicarb reabsorp (if binds bicarb buffer in filtrate) 4. PCT = unregged, DCT = regged in response changes blood pH 5. DCT = bicarb/prot synth

Answer 68

measure conc prots = -log10[H+]

Answer 69

metabolic reactions prod excess H+ + CO2 normally: homeostatic mechs get rid metabolic acid load by breathing

Answer 70

ECF (blood plasma) 7.35-7.45 * outside range affects all bod systems = coma, cardiac failure, circulatory collapse... * homeostatic pH control overrides all else

Answer 71

1. buffer systems temporarily bind H+/OH- = hide ions until excreted (first line) 2. change rate + depth breathing = CO2 exhaled/retained - faster = more CO2 + H+ out (subconscious) 3. kidney excr/reabsorp acidic (H+/NH4+) + basic (HCO3-/OH-) ions to eliminate acids (slow)

Answer 72

moderate changes in pH v fast by taking up ions * e.g. HCO3-, prots, Hb, phosphates NH3

Answer 73

more CO2 = more H+ + vice versa breathe shallow + slow = CO2 + H+ build up

Answer 74

* only if resp sys + control centres working normally * limited by availability bicarb ions (bicarb reserve) * can't protect against pH changes bc of incr/decr CO2

Answer 75

* respiratory when CO2 accumulates due hypoventilation - CO2 never accumulates blood healthy animals * metabolic when non-respiratory acids accumulate or bicarb deficient

Answer 76

= decr [HCO3-] due * diabetic ketoacidosis * kidney disease (didn't reabsorb) * faecal loss bicarb in diarrhoea

Answer 77

1. protons activate chemoreceptors 2. resp tract incr rate + depth breathing so pCO2 decr + plasma pH -> normal

Answer 78

lungs remove CO2 at lower rate than being proded due e.g. pneumonia = incr pCO2

Answer 79

alpha intercalated cells incr secr H+ -> filtrate

Answer 80

* respiratory alkalosis when CO2 in deficit - healthy animals = blood CO2 no decr below normal * metabolic alkalosis when non-respiratory acids lost or bicarb incr

Answer 81

incr [HCO3-] due * persistent vomiting (lose lots acid) * upper GI obstruction

Answer 82

resp tract decr rate + depth breathing to return plasma pH to normal = pCO2 incr

Answer 83

lungs remove CO2 at faster rate than being proded, e.g. due hyperventilation = decr pCO2

Answer 84

beta intercalated cells incr secr bicarb -> filtrate + synth H+ to reabsorb -> blood

Answer 85

1. normal thru kidneys (1-2ml/kg/hr) = sensible loss 2. insensible = evap from skin, exhalation from lungs, faeces

Answer 86

50ml/kg/day thru: * ingestion liquids/moist foods * metabolic synth water | polydipsia if >100ml/kg/day

Answer 87

25ml/kg/day polyuria if >50ml/kg/day

Answer 88

receptors respond changes * osmolarity * plasma vol * bp | no sensory receptors directly monitor water/Na+

Answer 89

can't restore lost just reg sensible water loss * reg ECF vol by adjusting excretion Na+ (+ so water that follows)

Answer 90

blood plasma osmolarity monitored osmoreceptors in hypothalamus * incr = incr rate of firing of neurons = incr ADH release decr below threshold = neurons no fibre = no ADH = dilute urine | incr osmolarity by 3% = stim thirst

Answer 91

1. osmolarity 2. blood vol directly - short term failsafe for sudden release lots ADH of whole blood lost so vol decr but osmolarity same 3. blood vol via angiotensin II

Answer 92

not regged so all ingested absorbed | no direct sensor like for K + Ca

Answer 93

extra % Na (e.g. 24% more) + water freely follows Na so blood vol incr by same %

Answer 94

stretch sensitive nerve endings in atria + veins detect incr bp by baroreceptors incr bp/blood vol = incr ANP = incr GFR = decr Na absorp = decr ADH, renin, symp output

Answer 95

reg reabsorp/excretion * angiotensin II + aldosterone promote reabsorp (+ so water reabsorp by osmosis) * natriuretic peptides promote excretion Na+ + Cl- followed by water excretion | to incr/decr blood vol

Answer 96

metric for kidney function looking at 1. constituents 2. urine vol 3. urine conc (SG)

Answer 97

* gluc * blood * prot - only filtered if kidney disease or high bp * ketones * cells - just occasional bladder epithelial

Answer 98

* normal = 1-2ml/kg/hr * polyuria = >2ml/kg/hr * oliguria = <1ml/kg/hr * anuria = no urine * isosthenuria = filtrate low SG

Answer 99

measure solutes in urine compared w distilled water | SG distilled water = 1.0000

Answer 100

variable bc depends hydration/bp * dogs = 1.001 - 1.075

Answer 101

urine SG as low as initial filtrate (prot free plasma 1.008-1.012) * suggests kidney pathology disrupting ability concentrate urine (or severe overhydration but that's rare) | should look for >1.035 cats, >1.030 dogs

Answer 102

phosphate, potassium, protons

Answer 103

bicarb, glucose

Answer 104

1. hyperkalaemia bc reabsorbed/not secreted 2. hyperphosphataemia bc reabsorbed/not secreted 3. metabolic acidosis - low pH + HCO3- decr (not reabsorbed) chronic disease can lead excess loss K + hypokalaemia (esp if anorexic + no consume daily K)

Answer 105

decr GFR 1. pre-renal azotaemia 2. renal (intrinsic) azotaemia 3. post renal azotaemia | not necessarily marker of damaged kidney

Answer 106

renal function normal but outflow blocked * e.g. ruptured bladder (cld be just small) * = decr GFR bc urine saturated/not moving = N waste reabsorbed/ not filtered * also other changes fluid + electrolyte balance (bad) | diagnosis usually straightforward

Answer 107

large systemic decr bp = decr blood flow -> kidney = decr GFR, e.g. due dehydration, heart disease * pathology upstream of kidney * animal can still conc urine (still prods ADH etc) = SG normal, indicating not intrinsic disease (for diagnostics) * = decr rate flow filtrate = incr time reabsorp = N waste in blood

Answer 108

due renal disease directly affecting renal function + so GFR * animal not prodding much urine or can't conc urine * = low SG * may also be abnormal stuff in urine

Answer 109

* incr conc N waste products * incr conc inorganic phosphate * incr conc K (anorexic may be hypokalaemic) * decr conc bicarb (-> metabolic acidosis)

Answer 110

* lack ability to conc = dilute * abnormal vol (too high or low)

Answer 111

1. acute kidney injury (AKI) 2. chronic kidney disease (CKD) | classic presentation = losing prot in urine (= weight loss)

Answer 112

rapid life-threatening impairment kidney function * = GFR decr + can't conc urine (+ stuff reabsorbed all = decr SG) * urine output zero, incr or decr

Answer 113

long term progressive loss kidney function * GFR decr + loss ability conc urine (water stays in) * urine output incr - owner won't notice bc outside but will notice incr drinking

Answer 114

* caps = porous endothelium * thick glomerular basement mem (physical barrier = size filter) * visceral epithelium (podocytes) - part Bowman's capsule * capsule space filtered into * parietal epithelium (simple squamous) w thick basal lamina - other part Bowman's capsule 1st 3 make up 3 components filtration barrier | mols captured base mem phagocyt by mesangial cells, podocytes phagocyt

Answer 115

ureter + bladder + urethra quite similar * all transitional epithelium * wavy mucosa profile allows expand acommodate urine * sub-mucosa w lamina propria * muscularis w inner longitudinal, middle circular + outer longitudinal (allow contraction) * then serosa (loose CT) in peritoneal cavity OR adventitia (loose CT) when embedded in other tiss | bladder has thicker layers sm musc (more contraction)

Answer 116

DCT (-> macula densa cells) + afferent arterioles (-> juxtaglomerular cells)

Answer 117

renal medullary pyramid + associated cortical tiss * unilobar kidney in cats, dogs, horses, sheep, goats * bovine + pig = kidneys multilobar

Answer 118

* neg charged prots * cellular components blood * big prots

Answer 119

1. thick descending limb - structure like PCT (cuboidal) 2. thin limb - simple squamous epithelium 3. thick ascending limb - structure like DCT (cuboidal)

urinary Flashcards

(145 cards)