Term
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Definition
| maintain serum composition, retain water, regulate osmotic pressure of body fluids, eliminate waste products/foreign compounds, regulate extracellular fluid volume, regulate arterial blood pressure, perform gluconeogenesis in prolonged starvation, degrade polypeptide hormones, and synthesize ammonia |
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Term
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Definition
| erythropoietin, calcitriol, prostaglandins, thromboxane, renin, and kallikrein |
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Term
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Definition
| stimulated by hypoxia, produced by renal cortex, stimulates production of erythrocytes and increases oxygen carrying capacity of blood |
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Term
| anemia in chronic liver failure |
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Definition
| due to deficiency of erythropoietin production |
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Term
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Definition
| produced by kidneys in response to decreased plasma calcium, also written as 1,25-OH2 vit D3, increases intestinal calcium absorption, promotes PTH action, and increases plasma calcium |
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Term
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Definition
| associated problems include calcium malabsorption, hyperparathyroidism, bone disease, and vascular calcification; results in decreased renal tubular mass, decreases 1-25-OH2 vit D3 synthesis |
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Term
| prostaglandins and thromboxanes |
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Definition
| modify inflammatory responses, formed from arachidonic acid by COX1 and 2 in the kidney, increase renal blood flow/Na excretion/renin release, and inhibit ADH action |
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Term
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Definition
| block synthesis of Angiotensin II and treat hypertension |
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Term
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Definition
| converts kininogens to active kinins, which are potent vasodilators, produced by kidney |
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Term
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Definition
| basic unit of kidney, approximately 1.2 million per kidney, several of them feed into one collecting duct, surrounded by capillaries, made up of glomerulus/proximal and distal tubules/collecting ducts |
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Term
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Definition
| blood vessels descending into the medulla from the efferent arterioles, follow loop of Henle |
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Term
| main driving force of filtration |
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Definition
| hydrostatic pressure in glomerular capillaries |
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Term
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Definition
| very high, approximately 25% of cardiac output, sustains high rate of plasma filtration and explains why kidney is important in regulating ECF volume/composition |
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Term
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Definition
| specialized region of nephron for reabsorption/secretion, has a large surface area/large # of mitochondria/leaky tight junctions, moves sodium to the basolateral side by pumps |
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Term
| juxtaglomerular apparatus |
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Definition
| composed of macula densa, granular cells, and extraglomerular mesangial cells; responsible for renin release and tubuloglomerular feedback |
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Term
| fluid flow past MD decreases |
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Definition
| JGA releases renin, angiotensin II is produced, and systemic vasoconstriction occurs; filtration and fluid flow past glomerulus ultimately increases |
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Term
| fluid flow past MD increases |
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Definition
| JGA reduces GFR (via local ATP/adenosine action), tubuloglomerular feedback occurs |
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Term
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Definition
| increase in prostaglandin in interstitium of JGA, PGE2 binds to EP4 (receptor)/stimulates renin release from granular cells |
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Term
| low concentration of AngII |
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Definition
| efferent arteriole primarily constricted, renal blood flow decreases but GFR increases due to hydrostatic pressure in glomerular capillaries |
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Term
| high concentration of AngII |
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Definition
| occurs during hemorrhage, both afferent and efferent arterioles are constricted to decrease both GFR and renal blood flow |
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Term
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Definition
| periodic emptying of urinary bladder, 150-250mL causes sensation of fullness, ureters maintain urine flow in one direction |
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Term
| hydrostatic pressure from outside glomerular capillaries |
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Definition
| acts to push fluid back into glomerulus, very small (15mmHg) |
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Term
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Definition
| AKA colloid osmotic pressure, acts to push fluid back into the glomerulus |
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Term
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Definition
| mL plasma/min that are cleared of a substance to supply the quantity of the substance in the urine in one minute's time, so = urine concentration*flow rate/plasma concentration |
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Term
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Definition
| =clearance rate of inulin, decreases with age, increases in females, approximately 180 L/day in healthy individual |
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Term
| plasma creatinine concentration |
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Definition
| correlates with GFR, doubling signals loss of 25% renal function (filtration) |
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Term
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Definition
| =GFR/renal plasma flow, approximately 20% |
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Term
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Definition
| = p-aminohippurate clearance |
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Term
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Definition
| = RPF/ (1-hematocrit), determines how much blood enters the kidney per minute |
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Term
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Definition
| used to drive sodium reabsorption, extraction LOW from arterial blood |
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Term
| blood flow rate in kidney |
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Definition
| high in cortex to allow high rate of filtration and low in medulla to avoid solute washout |
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Term
| autoregulation of RBF and GFR |
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Definition
| intrinsic property of kidney, minimizes impact of changes in mean arterial BP on GFR, overpowered by sympathetic nervous system during hemorrhage |
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Term
| myogenic mechanism of autoregulation |
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Definition
| changes in BP compensated by changes in vascular resistance; ex: increased BP leads to smooth muscle depolarizing in cortical arteries and afferent arterioles, causes increase in vascular resistance |
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Term
| autoregulation by TG feedback |
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Definition
| only in kidney, does not involve renin-angiotensin, negative feedback that prevents excess loss of Na+ in urine when increase in GFR/BP occurs, NaCl detected by macula densa--triggers constriction of afferent arterioles |
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Term
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Definition
| ATP released into interstitial fluid of JGA, ATP metabolized into adenosine, then vasoconstriction caused by A1 adenosine receptors in smooth muscle |
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Term
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Definition
| cause vasoconstriction, emergency function, routes blood to brain/heart, cause renin release, epi and norepi contribute to vasoconstriction |
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Term
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Definition
| work to increase RBF, ex: prostaglandins, NO, dopamine, atrial natiuretic peptide |
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Term
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Definition
| work to decrease RBF, ex: Ang II, epinephrine, norepinephrine, thromboxane A2, adenosine |
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Term
| NSAID to volume depleted patient |
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Definition
| very bad idea because it shuts down prostaglandins and reverses life-saving vasoconstriction |
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Term
| prostaglandins on renal vasoconstriction |
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Definition
| act as brakes, counteract increased plasma Ang II and renal sympathetic activity |
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Term
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Definition
| endothelial cells, podocytes, and mesangial cells |
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Term
| hallmark of glomerular disease |
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Definition
| heavy proteinuria due to loss of filtration barriers, causes tubular damage |
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Term
| 3 layers of glomerular filtration |
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Definition
| endothelium, basement membrane, and podocyte slit pores...endothelium is not major contributor (has fenestrae and allows everything except RBCs) |
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Term
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Definition
| integral protein in podocyte slit diaphragm, important barrier to filtration, negative charges play important role |
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Term
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Definition
| determined by Starling forces, = glomerular ultrafiltration coefficient(hydrostatic P in glomerular capillary - hydrostatic P in Bowman's space - colloid osmotic P in GC) |
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Term
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Definition
| hydrostatic pressure in glomerular capillary, depends on arterial BP and resistances of afferent/efferent arterioles |
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Term
| constriction/dilation of arterioles |
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Definition
| primary effect is to alter hydrostatic P in glomerular capillaries |
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Term
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Definition
| reduces hydrostatic P in glomerular capillaries, reduces GBF and GFR |
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Term
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Definition
| increases hydrostatic P in glomerular capillaries, increases GBF and GFR |
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Term
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Definition
| increases P of glomerular capillaries, reduces blood flow out of glomerulus, GFR can either increase or decrease depending on blood flow remaining |
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Term
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Definition
| decreases hydrostatic P in glomerular capillaries, increases GBF, decreases GFR |
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Term
| hydrostatic P in Bowman's space |
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Definition
| depends on GFR and downstream resistance, responds to tubular obstruction, will cause GFR to fall if it increases |
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Term
| colloid osmotic P in capillaries |
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Definition
| decrease (ex: following isotonic saline infusion) causes increase in GFR |
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Term
| glomerular blood flow's impact on COP |
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Definition
| when very low, the volume of filtrate is small and COP rises sharply, thus ceasing filtration along remainder of capillary; when high, rise in COP is minimal and filtration is sustained along capillary |
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Term
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Definition
| constant from birth to 45-50, then declines around 30-40%, important marker of renal function |
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Term
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Definition
| calculated by filtered load - (urine flow rate*concentration in urine) |
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Term
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Definition
| indicates whether substance is reabsorbed or secreted, determined by urinary excretion / filtered load --nearly 100% for inulin and zero for glucose |
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Term
| calculation of net secretion |
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Definition
| equals (concentration in urine * flow rate) - (plasma concentration * GFR) |
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Term
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Definition
| caused by nephrons having different carrying capacities of substances |
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Term
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Definition
| occurs in renal proximal tubule, electrochemical gradient helps movement in, co-transported w/ sodium, actively transported into peritubular capillary |
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Term
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Definition
| approximately 50% halfway across proximal tubule |
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Term
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Definition
| essentially iso-osmotic to plasma, reflects high water permeability, small gradient drives reabsorption of water |
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Term
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Definition
| disorder in which water is not reabsorbed due to faulty aquaporins, result is very dilute urine |
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Term
| reabsorption in proximal convoluted tubule |
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Definition
| filtered glucose and AAs almost 100%, filtered Na/water/K at 70%, filtered urea at 50% |
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Term
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Definition
| PAH is cleared completely by this mechanism, others include: carboxylic/sulfonic acids, amines/ammonium compounds, phenol red, penicillin, probenecid, furosemide, acetazolamine, and creatinine |
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Term
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Definition
| at PCT, is main driving force for reabsorption of solutes and water, consumes most oxygen and ATP in kidney, always uses Na/K/ATPase, actively transported to interstitial space |
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Term
| organic cations secreted by PTs |
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Definition
| histamine, cimetidine, cisplatin, norepinephrine, quinine, tetraethylammonium, creatinine |
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Term
| lipid soluble organic compound secretion |
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Definition
| undergo non-ionic diffusion, explains use of sodium bicarbonate in sedative overdoses |
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Term
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Definition
| ascending limb is impermeable to water, thick ascending limb absorbs solutes without water (diluting segment), ascending limb increases osmolarity of medullary interstitium |
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Term
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Definition
| ex: furosemide and bumetanide, Na/K/2Cl co-transporter is inhibited on tubular side, allows for less deposition of Na in medullary interstitium and increases water and Na excretion |
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Term
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Definition
| consists of convoluted tubule, connecting tubule, and initial cortical collecting duct |
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Term
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Definition
| consists of DCT, connecting tubule, cortical collecting duct, outer medulla collecting duct, and inner medulla collecting duct...basically everything beyond the loop |
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Term
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Definition
| work on the Na/Cl co-transporter in the luminal cell membrane of the distal convoluted tubule, causes more Na to be delivered to the collecting duct and limiting of reabsorption of water |
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Term
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Definition
| block Na/Cl co-transporter in distal convoluted tubule, ex: chlorothiazide and metolazone |
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Term
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Definition
| composed of 2/3rds principal cells and 1/3rd intercalated cells, has tight epithelium, determines final excretion of sodium/potassium/hydrogen, reabsorbs Na through ENaC channels, secretes K, completely impermeable to water |
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Term
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Definition
| sites of action of aldosterone and ADH, reabsorbs Na and secretes K |
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Term
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Definition
| in collecting duct, important for acid-base homeostasis, alpha type secrete H+/reabsorb K during dietary depletion/predominate during acidosis, beta type secrete bicarbonate and predominate during alkalosis; |
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Term
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Definition
| antiporter that releases bicarbonate into blood in alpha intercalated cells |
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Term
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Definition
| antiporter that transports bicarbonate into lumen and Cl into cell |
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Term
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Definition
| caused by defect in SGLT (Na/glucose co-transporter) |
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Term
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Definition
| caused by defect in amino acid transporter, damages kidney |
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Term
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Definition
| affects Na/K/2Cl co-transporter |
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Term
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Definition
| affects NaCl co-transporter |
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Term
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Definition
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Term
| nephrogenic syndrome of inappropriate antidiuresis |
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Definition
| caused by increased V2 receptor activity (AQP2) |
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Term
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Definition
| control distribution of fluid between plasma and interstitium |
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Term
| result of adding 2.0L pure water |
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Definition
| ICF volume expands w/o proper correction, volume increases while osmolarity decreases |
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Term
| result of adding 2.0L of isotonic saline |
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Definition
| fluid volume expansion stays in ECF, GFR increases to correct it, kidneys will excrete Na and water |
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Term
| result of adding 5% NaCl saline solution |
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Definition
| increase in salt concentration increases ECF volume, increase in osmolarity causes cellular shrinkage, kidneys will correct it with ADH |
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Term
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Definition
| stimulated by cellular dehydration (increased osmolarity of ECF) and fall of ECF volume, mediated by changes sensed by baroreceptors and osmoreceptors |
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Term
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Definition
| respond to increases in osmolarity, trigger neurons to release AVP and thirst sensation |
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Term
| factors influencing ADH release |
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Definition
| cellular dehydration (increase in effective plasma osmolarity), hypovolemia, a decrease in effective arterial blood volume, pain/trauma/emotional stress/etc., ethanol/atrial natriuretic peptide |
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Term
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Definition
| action eliminates pooling of blood due to gravity, blood moves to central vessels, increased volume is signaled, causes decrease in ADH and increase urge to urinate |
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Term
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Definition
| sensed by cardiovascular stretch receptors and osmoreceptors, which decreases ADH release and less water is reabsorbed; NOTE: reabsorption at PT is not altered |
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Term
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Definition
| body tries to first restore fluid volume by reabsorbing water in collecting ducts and then restore osmolarity by adding Na back |
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Term
| effective arterial blood volume |
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Definition
| is of overriding importance, ex: congestive heart failure signals decreased arterial blood volume and ultimately causes hyponatremia and brain swelling to maintain "normal" blood volume |
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