front 1 what are the three funcitons of the urinary system? | back 1 excretion elimination and homeostatic regulation |
front 2 how does the urinary system help regulate blood volume and blood pressure? | back 2 by adjusting the volume of water lost in the urine and releasing erythropoietin and renin |
front 3 how does the urinary system help regulate plasma ion concentration? | back 3 by controlling quantities of sodium potassium and chloride ions lost in urine and by controlling calcium levels through syntesis of calcitriol |
front 4 how does the urinary system help stabilize blood pH? | back 4 by controlling loss of hydrogen ions and bicarbonate ions in urine |
front 5 how does the urinary system conserve valuable nutrients? | back 5 by preventing excretion while excreting organic waste products |
front 6 what does the urinary system assist the liver with? | back 6 detoxifying poisons |
front 7 what is the renal cortex? what color and texture is it? | back 7 the superficial portion of kidneys in contact with renal capsule; reddish brown and granular |
front 8 what are renal pyramids? | back 8 6 to 8 distinct conical or triangular structures in renal medulla |
front 9 where are the base and tip found | back 9 base is abuts the cortex and the tip (renal papilla) project into renal sinus. |
front 10 how much of the total cardiac output does the kidneys recieve? | back 10 20%-25% |
front 11 what are the two types of nephrons? | back 11 cortical and juxtamedullary |
front 12 which type of nephron make up 85% of all nephrons? | back 12 cortical |
front 13 where are the cortical nephrons located? | back 13 within the superficial cortex of kidneys |
front 14 compare the nephron loop (loop of henle) of the cortical to the one of the juxtamedullary | back 14 the cortical nephron is relatively short while the one of the juxtamedullary extends deep into the medulla |
front 15 what does the efferent arteriole of the cortical nephron do? | back 15 delivers blood to a short network of peritubular capillaries |
front 16 what do the peritubular capillaries of the juxtamedullary nephron do? | back 16 connect to vasa recta |
front 17 what does a large loop mean? | back 17 more concentrated urine |
front 18 what are the two segments of the renal tubule and where are they located? | back 18 proximal convoluted tubule and distal convoluted tubule; cortex |
front 19 what are the segments of the renal tubule seperated by? | back 19 nephron loop |
front 20 what is the nephron loop? | back 20 a u-shaped tube that extends partially into the medulla |
front 21 is filtration at the renal corpuscle active or passive? | back 21 passive; no atp is necessary |
front 22 what kind of solutes enter capsular space during filtration? | back 22 metabolic waste and excess ions like glucose, free fatty acids, amino acids, and vitamins |
front 23 what is reabsorption and where does it occur | back 23 when useful materials that are recaptured before filtrate leaves kidneys and it occurs in proximal convoluted tubule |
front 24 what is the first segment of the renal tubule and where is the entrance to this segment? | back 24 proximal convoluted tubule; opposite to the point of connection of afferent and efferent arterioles with glumerulus |
front 25 describe the epithelial lining of PCT. what does it do? | back 25 simple cuboidal with microvilli on apical surfaces. the fuunction is reabsorption and it secretes substances into lumen |
front 26 what is the nephron loop | back 26 renal tubule that turns toward renal medulla |
front 27 what are the two limbs of the nephron loop? what does each contain? | back 27 descending and ascending; thick and thin segement |
front 28 what does the thick descending limb do? what is its function similar to? | back 28 pump sodium and chloride ions out of tubular fluid; PCT |
front 29 where is the ascending limb? what does it do? | back 29 juxtamedullary nephron in the medulla; it creates high solute concentrations in peritubular fluid |
front 30 what are the thin segments permeable to? what dos the movement of this help? | back 30 water only,not solute; helps concentrate tubular fluid |
front 31 where does the thick ascending limb end? | back 31 at a sharp angle near the renal corpuscle where DCT begins |
front 32 what arethe three organic waste produces? | back 32 urea, creatine and uric acid |
front 33 where are organic waste dissolved, when are they eliminated, and what does their removal include? | back 33 dissolved in bloodstream, eliminated only while dissolved in urine and removal is accompanied by water loss |
front 34 what are the three components of the membrane involved in glomerular filtration | back 34 capillary endothelium, dense layer, and filtration silts |
front 35 what type of capillary are glomerular capillaries? what do their pores do? | back 35 fenstrated; prevent passage of blood cells and allow diffusion of solutes including plasma protiens |
front 36 what is glomerular filtration governed by? | back 36 the balance between hydrostatic pressure and colloid osmotic pressure on either side of capillary walls |
front 37 what is glomerular hydrostatic pressure? what does it tend to do? | back 37 blood pressure in glomerular capillaries; push water and solute molecules out of plasma into filtrate |
front 38 why is the hydrostatic pressure significantly higher than capillary pressure in systemic circuit. | back 38 arrangement of vessels at gloerulus |
front 39 where does blood leaving glomerular capillaries do? how does the diameter of this arteriole compare to the other | back 39 flow into an efferent arteriole with a diameter smaller than afferent arteriole |
front 40 what does the efferent arteriole produce? what does this require? | back 40 resistance; relatively high pressure to force blood into it |
front 41 what is capsular hydrostatic pressure? what does it do? what does it result from? | back 41 capsular hydrostatic pressure that opposes glomerular hydrostatic pressure; pushes water and solutes out of filtrate into plasma; resistance to flow along nephron and conducting system (avg is 15 mm Hg) |
front 42 what is the net hydrostatic pressure? | back 42 difference between glomerular hydrostatic pressure and capsular hydrostatic pressure |
front 43 what is colloid osmotic pressure? | back 43 osmotic pressure resulting from the presence and capsular hydrostatic pressure |
front 44 what does blood colloid osmotic pressure tend to do? | back 44 draw water out of filtrate into plasma. opposes filtration (avg is 25 mm Hg) |
front 45 what is net filtration pressure? | back 45 average pressure forcing water and dissolved materials out of glomerular capillaries into capsular spaces |
front 46 what is there a difference between at the glomerulus? | back 46 hydrostatic pressure and BCOP accross glomerular capillaries |
front 47 what is the creatinine clearance test used for? | back 47 to estimate GFR |
front 48 how much flitrate is generated in glomeruli each day? where is 99% of it reabsorbed? | back 48 180 liters; renal tubules |
front 49 wht three interacting levels control the GFR | back 49 autoregulation, hormonal regulation, and autonomic regulation |
front 50 what are the hormonal regulations of the GFR? | back 50 renin-angiotensin system and natiutic peptides (ANP and BNP) |
front 51 what three stimuli causes the juxtagloumerular complex to relesase renin? | back 51 1. decline in blood pressure at glomerulus due to decrease in blood volume fall in systemic pressures, or blockage in renal artery or tributaries
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front 52 what does angiotensin II activation do? | back 52 constricts efferent arterioles of nephron elevating glomerular pressure, stimulates reabsorption of sodium ions and water at PCT, stimulates secretion of aldosterone by adrenal cortex, stimulates thirst, and triggers release of ADH which stimulates reabsorption of water in distal portion of DCT and collecting system |
front 53 what does angiotension II do? | back 53 increases sympathetic motor tone, causes a brief powerful vasconstriction, and elevates arterial pressures throughout the body |
front 54 was do the increase of sympathetic motor tone by angiotensin II cause to happen? | back 54 mobilizes the venous reserve, increases cardiac output and stimulates peripheral vasoconstriction |
front 55 what does aldosterone do? | back 55 accelerates sodium reabsortion in DCT and cortical portion of collecting system |
front 56 what are natriuretic peptides? what do they do? | back 56 hormones that regulate GFR; trigger dilation of afferent arterioles and constriction of efferent arterioles and elevate glomerular pressure and increase GFR |
front 57 where are natriuretic peptides released and when? | back 57 by the heart in response to stretching walls due to increased blood volume or pressure |
front 58 what are the two types of natriuretic hormones and where are they released? | back 58 atrial natriuretic peptide (ANP) released by the atria and Brain natriuretic peptide (BNP) released by ventricles |
front 59 what does reabsorption do? | back 59 recover useful materials from filtrate |
front 60 what does secretion do? | back 60 ejects waste products, toxins, and other undesirable solutes |
front 61 where does reabsorption and secretion occur? what changes from segment to segment with these two things? | back 61 in every segment of nephron except renal corpuscle; relative importance |
front 62 how much of the filtrate produced in the renl corpuscle does the PCT cells usually reabsorb? where does this reabsorbed material go? | back 62 60-70%; it enters the peritubular fluid and diffuse into peritubular capillaries |
front 63 what are the five functions of the PCT? | back 63 reabsorption of organic nutrients, active reabsorption of ions, reabsorption of water, passive reabsorption of ions, secretion |
front 64 what is important in every pct process? | back 64 sodium ion reabsorption |
front 65 how do sodium ions enter tubular cells? | back 65 diffusion through leak channels; sodium lined cotransport organic solutes, and countertransport for hydrogen ions |
front 66 how does the nephron loop reabsorb around half the water and 2/3 of the sodium an chloride ions remaining in tubular fluid | back 66 by the process of countercurrent exchange |
front 67 what is countercurrent multiplication? | back 67 the exchange that occurs between the two parallel segments of loop of henle- the thin descending limb and the thick ascending limb |
front 68 what does countercurrent refer to? | back 68 the exchange between tubular fluids moing in opposite directions ( fluid n descending limb flows toward renal pelvis and fluid in ascending limb flows toward cortex) |
front 69 what does multiplication refer to? | back 69 the effect of exchange hat increases as movement of fluid continues |
front 70 what are the parallel segments of the nephron loop separated by? how do their characteristics compare? | back 70 peritubular fluid; they are very different |
front 71 describe the permeability to the thin descending limb | back 71 permeable to water and relatively impermeable to solutes |
front 72 describe the permeability of the thick ascending limb. what does it contain? | back 72 relatively impermeable to water and solutes. it contains an active transpor mechanism that pumps Na+ and Cl- from tubular fluid into peritubular fluid of medulla |
front 73 what do sodium and chloride pumps do? | back 73 elevate osmotic concentration in peritubular fluid around thin descending limb and causes osmotic flow of water out of thin descending limb and into peritubular fluid which increases solute concentration in thin descending limb |
front 74 where does the concentrated solution arrive and what does it cause? | back 74 thick ascending limb and accelerates Na+ and Cl- transport into peritubular fluid of medulla |
front 75 what does solute pumping at ascending limb cause? | back 75 and increase solute concentration in descending limb which accelerates solute pumping in ascending limb |
front 76 where does contercurrent multiplication occur? what does it move and where does it move it? | back 76 apical surface; Na+, K+, and Cl- out of tubular fluid |
front 77 what is the carrier protein used in contercurrent multiplication | back 77 Na+-K+/2Cl- |
front 78 describe the route for potassium ions. | back 78 pumped into peritubular fluid by cotransport carriers, removed from peritubular fluid by sodium- potassium exchange pump,and diffuse back into lumen of tubule through potassium leak channels |
front 79 describe the route for sodium and chloride ions. | back 79 removed from tubular fluid in ascending limb which elevates osmotic concentration of peritubular fluid around thin descending limb |
front 80 what happens as tubular fluid flows along thin descending limb? | back 80 osmosis moves water into peritubular fluid, leaving solutes behind. osmotic concentration of tubular fluid increases |
front 81 where are 2/3 of Na+ and Cl- in tubular fluid pumped out before reaching DCT causing the solute concentration to decline and why? | back 81 thick ascending limb because of the highly effectie pumping mechanism |
front 82 what is the osmotic concentration of tubular fluid at the DCT? | back 82 100 mOsm/L |
front 83 what is the rate of ion transport across thick ascending limb proportional to? | back 83 ion's concentration in tubular fluid |
front 84 where are more Na+ and Cl- pumped into medulla? | back 84 at the start of thick ascending limb near cortex |
front 85 what does the regional difference in the ion transport rate cause? | back 85 concentration gradient within medulla |
front 86 what is the maximum solute concentration of peritubular fluid near the turn of the nephron loop? how much of this is from Na+ and Cl- pumped out of ascending limb? what is the remainder? | back 86 1200 mOsm/L; 2/3; from urea |
front 87 what locations are impermeable to urea? | back 87 thic ascending limb, DCT, and collecting ducts |
front 88 what happens to the concentration of urea as water is reabsorbed? | back 88 the concentration rises |
front 89 how many mOsm/L of urea are found in tubular fluid reaching papillary ducts? | back 89 450 |
front 90 what is permeable to urea? | back 90 papillary ducts |
front 91 what are two benefits of contercurrent multiplication? | back 91 efficiently reabsorbs solutes and water before tubular fluid reaches DCT and collecting system and it establishes a concentration gradient that premits passive reabsorption of water form tubular fluid in collecting system. |
front 92 what is aldosterone and what all does it do? | back 92 a hormone produced by the adrenal cortex that controls ion pump and channels, stimulates synthesis and incorporation of Na+ pumps and channels in plasma membranes along DCT and collecting ducts and reduces Na+ lost in urine |
front 93 what is produced by prolonged aldosterone stimulation and dangerously reduces plasma concentration? | back 93 hypokalemia |
front 94 what opposes secretion of aldosterone and its actions on DCT and collecting system? | back 94 natriuretic peptides (ANP and BNP) |
front 95 what regulates calcium ion reabsorption at he DCT? | back 95 parathyroid hormone and calcitriol |
front 96 what is contained in blood entering peritubular capillaries? | back 96 undesirable substances that did not cross filtration membrane at glomerulus |
front 97 what causes the rate of K+ and H+ secretions to rise or fall and how? | back 97 the concentrations in peritubular fluid. higher concentration and higher rate of secretion |
front 98 how do potassium ions diffuse into lumen? | back 98 through potassium leak channels |
front 99 what do tubular cells exchange? | back 99 Na+ in tubular fluid for excess K+ in body fluids |
front 100 what generates hydrogen ion secretions? | back 100 dissociation of carbonic acid by the enzyme carbonic anhydrase |
front 101 what does hydrogen ion secretion do? what causes it to accelerate? | back 101 acidifies tubular fluid,elevates blood pH, and accelerates when blood pH falls |
front 102 what is acidosis and when does it develop? | back 102 lactic acidosis and develops after exhaustive muscle activity |
front 103 what causes ketoacidosis to develop? | back 103 starvation or diabetes mellitus |
front 104 what controls blood pH? what are these important to? | back 104 H+ removal and bicarbonate production at kidneys; homeostasis |
front 105 what is alkalosis? what can cause it? | back 105 abnormally high blood pH; prolonged aldosterone stimulation which stimulates secretion |
front 106 what are the responses to acidosis? | back 106 PCT and DCT deaminate amino acids, ammonium ions are pumped into tubular fluid and bicarbonate ions enter bloodstream through peritubular fluid |
front 107 what do PCT and DCT deaminate amino acids do? | back 107 ties up H+ and yields ammonuium ions (NH4+) and bicarbonate ions (HCO3-) |
front 108 what are some benefits of tubular deamination? | back 108 provides carbon chains for catabolism and generates bicarbonate ions to buffer plasma |
front 109 describe reabsorption and secretion at collecting ducts? | back 109 receives tubular fluid from nephron and carries it toward renal sinus |
front 110 how is water and solute loss regulated in the collecting system? | back 110 by aldosterone and ADH |
front 111 what does aldosterone control? what is it opposed by? | back 111 sodium ion pumps and actions are opposed by natiuretic peptides |
front 112 what does ADH control and what is it suppressed by? | back 112 permeability to water; natriuretic peptides |
front 113 what is reabsorbed in the collecting system? | back 113 sodium ions, bicarbonate, and urea |
front 114 what is secreted in the collecting system and why? | back 114 hydrogen or bicarbonate ions. it controls body fluid pH |
front 115 what happens when there is a low pH in peritubular fluid. | back 115 carrier protiens pump H+ into tubular fluid and reabsorbs bicarbonate ions |
front 116 what happens when there is a high pH in peritubular fluid. | back 116 collecting system secretes bicarbonate ions and pumps H+ into peritubular fluid |
front 117 how is urine volume and osmotic concentration controlled? | back 117 through control of water reabsorption |
front 118 how is water reabsorbed? | back 118 through osmosis in proximal convoluted tubule and descending limb of nephron loop |
front 119 what does ADH cause to appear in apical cell membranes and why? | back 119 water channels (aquaporins) to increase the rate of osmotic water movement |
front 120 what does higher levels of ADH increase? | back 120 number of water channels and water permeability of DCT and collecting ststem |
front 121 what happens if there is no ADH? | back 121 water is not reabsorbed and all fluid reaching DCT is lost in urine producing large amounts of dilute urine |
front 122 what causes DCT and collecting systems to always be permeable to water? | back 122 the hypothalamus is continuously secreting ADH |
front 123 how much urine does a healthy aduly produce per day? | back 123 1200 mL with osmotic concentration o 800-1000 mOsm/L |
front 124 what is diuresis? what does it typically indicate? | back 124 the elimination of urine typically indicating production of large volumes of urine |
front 125 what is diuretics? | back 125 drugs that promote water loss in urine |
front 126 what does diuretic therapy reduce? | back 126 blood volume, blood pressure and extracellular fluid volume |
front 127 what is the function of the vasa recta? | back 127 to return solutes and water reabsorbed in medulla to general circulation without disrupting the concentration gradient |
front 128 what is the osmotic concentration of blood entering the vasa recta? | back 128 300 mOsm/L |
front 129 when does the osmotic concentration of blood to increase? what does it involve? | back 129 as the blood descends into the medulla. it involves solute absorption and water loss |
front 130 what does blood flowing toward the cortex do? what does it involve? | back 130 gradually decreases with solute concentration of peritubular fluid. it involves solute diffusion and osmosis |
front 131 what does the vasa recta carry out of the medulla and why? | back 131 water and solute; balances solute reabsorption and osmosis in medulla |
front 132 what are the seven steps of renal function | back 132 1. glomerulus
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front 133 what has the same composition as blood plasma? | back 133 filtrate produced at renal corpuscle |
front 134 what happens during step two of renal function? | back 134 active removal of ions and organic substrates (produces osmotic water flow out of tubular fluid that reduces volume of filtrate and keeps solutions inside and outside tubule isotonic |
front 135 what happens during step three of renal function?what is there a reduction in and why? | back 135 water moves into peritubular fluids, leaving highly concentrated tubular fluid. a reduction in volume occurs by obligatory water reabsorption |
front 136 what happens during step four of renal function? what accounts for a higher proportion of total osmotic concentration? | back 136 tubular cells actively transport sodium and chloride out of tubule. urea account for higher proportion of total osmotic concentration. |
front 137 what happens during step five of renal function? what is adjusted and how? | back 137 final adjustments in composition of tubular fluid; osmotic concentration through active transport |
front 138 what happens during step six of renal function? what is exposed here and what does it determine? | back 138 final adjustments in volume and osmotic concentration of tubular fluid; ADH, final urine concentration |
front 139 what happens during step seven of renal function? what does it maintain? | back 139 absorbed solutes and water reabsorbed by nephron loop and the ducts; concentration gradient of medulla |