Renal physiology revision (Dr. Ramadan) 1) Autoregulation of the GFR stops when arterial blood pressure drops below: a) 120mmHg b) 100mmHg c) 80mmHg d) 90mmHg 2) Increased GFR will increase NaCl in the loop loop of Henle, which is sensed by the macula densa, and finally leads to: a) Decreased afferent arteriolar resistance b) Increased afferent arteriolar resistance c) Decreased efferent arteriolar resistance d) Increased efferent arteriolar resistance 3) What is the major role of the juxtamedullary nephrons? a) Conveys oxygen to nephron segments b) Conveys nutrients to nephron segments c) Serves as a pathway for the return of reabsorbed water and solutes d) Delivers substances for nephron secretion e) Concentrates and dilutes urine 4) Which of the following is NOT true of juxtamedullary nephrons? a) glomeruli present in the outer medulla b) Are composed of long loops of Henle c) have no Juxtaglomerular Juxtaglomerula r apparatus. apparatus . d) Essential in the urine-concentrating urine-concentrating mechanism e) Extend into the inner region of the medulla. 5) What is a function of the macula densa cells? a) No function b) Renin secretion c) Calcitonin secretion d) Sodium sensing and vasopressor secretion e) Prostaglandin and proinflammatory proinflammatory cytokine secretion 6) Renal autoregulation (A) Is associated with increased renal vascular resistance when arterial blood pressure is lowered from 100 to 80 mm Hg (B) Mainly involves changes in the diameter of efferent arterioles (C) Maintains a normal renal blood flow during severe hypotension (below 50mm Hg) (D) Minimizes the effect of changes in arterial blood pressure on renal Na excretion (E) Requires intact renal nerves 7) Renal blood flow: a. is 600-650 ml/min per kidney b. is directly measured by infusing inulin c. is increased by sympathetic tone d. is greater in the medulla compared to the cortex. e. is closely related to tubular sodium reabsorption 8) Which has the greatest renal clearance a. PAH b. Glucose c. Urea d. Water e. Inulin 9) Constriction of efferent arterioles would lead to: a) Reduced filtration and increased urine production b) Reduced filtration and reduced urine production c) Increased filtration and increased urine production d) Increased filtration and reduced urine production
10) Constriction of afferent arterioles would lead to: a) Reduced filtration and increased urine production b) Reduced filtration and reduced urine production c) Increased filtration and increased urine production d) Increased filtration and reduced urine production e) Vastly increased urinary output 11) the glomerular filtration rate changes in direct proportion to the following in most cases A. capsular osmotic pressure B. glomerular hydrostatic pressure C. afferent arteriolar constriction D. renal blood flow 12) A substance with a clearance value 200ml/minute is: a) Freely filtered and is neither reabsorbed nor secreted by renal tubules. b) Subjected to partial tubular reabsorption. c) Subjected to tubular secretion. d) Completely reabsorbed in renal tubules. 13) If a substance appears in the renal artery but not in the renal vein, a. Its clearance is equal to the glomerular filtration rate b. It must be reabsorbed by the kidney c. Its urinary concentration must be higher than its plasma concentration d. Its clearance is equal to the renal plasma flow e. It must be filtered by the kidney 14) About the glomerular filtration rate, all of the following is correct except: a) It is about 125 ml / minute. b) It depends mainly on the glomerular capillary hydrostatic pressure. c) It is increased by vasodilatation of afferent arterioles. d) It is increased by increased plasma proteins oncotic pressure. 15) The clearance of inulin can be used to determine glomerular filtration rate (GFR) because A. inulin is freely filtered and only and all of the filtered inulin is excreted B. all of the inulin entering the glomerulus is filtered into Bowman's space C. the amount of inulin excreted is equal to the amount entering the glomerulus D. inulin is a small molecular weight compound E. the concentration of inulin in plasma is equal to the concentration of inulin in final urine 16) The renal clearance equation calculates A. the amount of a compound excreted per minute. B. the volume of plasma that originally contained the amount excreted per minute. C. the rate that plasma is flowing through the afferent arteriole. D. the volume of plasma that is filtered into Bowman's space per minute. E. the volume of urine excreted per minute 17) Test of renal clearance of inulin and creatinine are used to provide information about: a. renal blood flow, b. glomerular filtration, c. tubular reabsorption, c. tubular secretion. 18) Which of the following statements about glomerular filtration is not correct? a. glomerular capillary hydrostatic pressure is normally about 60 mmHg. b. net ultrafiltration pressure in the glomerular capillaries is 10mmHg. c. glomerular plasma oncotic pressure is equal to the hydrostatic pressure in Bowman's space. d. the ultrafiltration coefficient, can be altered by some vasoactive hormones.
19) The ascending limb of the Loop of Henle is: A. Impermeable to Na+ B. Involved in active transport of K+ into the lumen C. Involved in active transport of Cl- out of lumen D. Involved in active transport of Na+ into lumen E. Hypotonic at the tip 20) Pressure diuresis: A. Due to decreased reabsorption of Na+ & water in peritubular capillaries B. Regulated by macula densa C. Increase ADH D. Increase angiotensin E. Control by JGA 21) What is a role of the thin ascending limb of the loop of Henle? a) Exchanges Na+ for K+ under aldosterone regulation b) Allows for passive diffusion of NaCl into the interstitium c) Has ADH-regulated water channels and contains light and dark cells d) Has a positive gradient for re-absorption of ions such as Ca++ and Mg+ e) Permeable allowing for water diffusion out and salt diffusion in 22) What is a role of the distal convoluted tubule? a) Exchanges Na+ for K+ under aldosterone regulation b) Allows for passive diffusion of NaCl into the interstitium c) Has a positive gradient for re-absorption of ions such as Ca++ and Mg+ d) Permeable allowing for water diffusion out and salt diffusion in 23) Glucose reabsorption in renal tubules: a) Has no Tm. b) Across the luminal border of the proximal convoluted tubules is by facilitated diffusion. c) Is coupled to sodium reabsorption in the proximal convoluted tubules. d) Occurs equally in every segment of the nephron. 24) What is a role of the thick ascending limb? a) Exchanges Na+ for K+ under aldosterone regulation b) Allows for passive diffusion of NaCl into the interstitium c) Has ADH-regulated water channels and contains light and dark cells d) Has a positive gradient for re-absorption of ions such as Ca++ and Mg+ e) Permeable allowing for water diffusion out and salt diffusion in 25) At plasma concentrations of glucose higher than the renal threshold, the a) Clearance of glucose is zero. b) Excretion rate of glucose equals the filtration rate of glucose. c) Reabsorption rate of glucose equals the filtration rate of glucose. d) Excretion rate of glucose increases with increasing plasma glucose concentration. e) Reabsorption rate of glucose increases with increasing filtration rate. 26) In the proximal convoluted tubules: a) Only 30% of the filtered water is reabsorbed. b) The luminal fluid is iso-osmotic to plasma. c) Hydrogen ions are actively reabsorbed. d) Potassium ions secretion is controlled by aldosterone. 27) Renal handling of Na+ in the PCT includes all of the following except: a) About 70 % of filtered load is reabsorbed. b) Na + reabsorption at the luminal border is an active process. c) Na + reabsorption is accompanied by glucose and amino acid co-transport. D) In the late proximal tubule Na+ reabsorption is accompanied by CI-reabsorption. 28) Sodium reabsorption:
a) Occurs in every segment of the nephron except the ascending limb of loop of Henle. b) Is coupled with k+ and H+ excretion in the distal convoluted tubules. c) In proximal convoluted tubules accounts for 90% of the filtered sodium. d) In proximal convoluted tubule occurs via the tranc-cellular but not the para-cellular route. 29) Loop diuretics: a) Increase Na+ and K+ reabsorption. b) Decrease Na+ and K+ secretion. c) Decrease Na+ reabsorption and increase K+ secretion. d) Increase Na+ reabsorption and K+ secretion. 30) Bicarbonate: a) Is subjected to tubular secretion in the proximal convoluted tubules. b) Is responsible for concentration of urine. c) Absorption depends on H + secretion. d) Absorption is linked to chloride reabsorption. 31) In the descending limb of the loop of Henle: a) Chloride ions are actively pumped. b) Osmolarity of tubular fluids increases as it descends. c) The wall is impermeable to water. d) Glucose reabsorption is completed. 32) K+ in the kidney is: a) Freely filtered, neither reabsorbed nor secreted. b) Freely filtered, secreted but not reabsorbed. c) Freely filtered, reabsorbed and secreted. d) Freely filtered, reabsorbed and not secreted. 33) In distal convoluted tubules: a) Aldosterone increases K+ reabsorption. b) Aldosterone increases active water reabsorption. c) Highly permeable to urea. d) The wall is impermeable to water in absence of ADH. 34) K+ secretion by the distal tubule will be increased by all of the following except a) Metabolic alkalosis. b) High K+ diet. c) Hyperaldosteronism. d) Spironolactone diuretic. e) Loop diuretics. 35) In the thick ascending limb of the loop of Henle: a) Cl - ions are reabsorbed passively through the paracellular route. b) The osmolarity of the luminal fluid decreases as it ascends. c) Water reabsorption is under the influence of ADH. d) Glucose reabsorption is completed. 36) In water diuresis: a) There is an increased solute excretion. b) The osmolarity of urine is far less than that of plasma. c) The decreased water reabsorption is mainly in proximal convoluted tubules. d) There is no effect of ADH injection. 37) K+ sparing diuretics: a) Inhibit Na+ reabsorption in the distal tubule. b) Inhibit K+ reabsorption in the distal tubule. c) Are aldosterone antagonists. d) a & c are correct. 38) Which of the following is a part of the counter current multiplier mechanism?
a) Active transport of NaCl in proximal convolute tubules. b) Active transport of NaCl in collecting tubule. c) Active transport of NaCl in ascending limb of the loop of Henle. d) Active transport of NaCl in distal convoluted tubules. 39) During osmotic diuresis: a) Decreased water reabsorption is in DCT due to absence of ADH. b) Osmolarity of urine is below that of plasma. c) Volume of urine increases because of the increased amount of non-absorbable solutes in urine. d) Is observed in diabetes insipidus. 40) K+ secretion is characterized by all the following except: a) Occurs mainly in the proximal convoluted tubule. b) At the baso-lateral border it is an active process. c) It is affected by dietary K, aldosterone and acid base balance. d) It is increased by the use of loop diuretics. 41) Which of the following substances is the least reabsorbed, with only about 50% reentering the renal tubules? a) Water b) Na+ c) K+ d) Glucose e) Urea 42) Which of the following is completely reabsorbed into the renal tubule? a) Na+ b) K+ c) Ca++ d) HCO3e) Glucose 43) No water reabsorption occurs in which of the following locations? a) Proximal tubule b) thick ascending LH. c) Descending loop of Henle d) Collecting duct 44) All of the following Na entry mechanisms seen in the proximal tubule except a) Na+ cotransport with glucose b) Na+ cotransport with amino acids c) Na+, K+, 2Cl- symport d) Na+/H+ exchange e) Na+ cotransport with organic solutes 45) What percentage of the NaCl reabsorbed at the thick ascending limb of the Henle loop is via the transcellular pathway? a) 25% b) 33% c) 50% d) 66% e) 75% 46) Which of the following is a part of the counter current multiplier mechanism? a) Active transport of NaCl in proximal convolute tubules. b) Active transport of NaCl in collecting tubule. c) Active transport of NaCl in ascending limb of the loop of Henle. d) Active transport of NaCl in distal convoluted tubules. 47) Select the correct answer about proximal tubules :
a) K+ is secreted in exchange with the Na+ under the effect of aldosterone b) glucose , amino acids & proteins are completely reabsorbed c) only 10% of the filtered water is reabsorbed d) parathormone increase phosphate reabsorption . 48) In water diuresis: a) There is an increased solute excretion. b) The osmolarity of urine is far less than that of plasma. c) The decreased water reabsorption is mainly in proximal convoluted tubules. d) There is no effect of ADH injection. 49) During osmotic diuresis: a) Decreased water reabsorption is in DCT due to absence of ADH. b) Osmolarity of urine is below that of plasma. c) Volume of urine increases because of the increased amount of non-absorbable solutes in urine. d) Is observed in diabetes insipidus. 50) Sodium is passively reabsorbed in which of the following nephron segments? A. proximal tubule B. distal tubule C. thick ascending limb of the loop of Henle D. thin ascending limb of the loop of Henle E. none of the above 51) If plasma inulin concentration is 0.2 μg/mL, urine flow is 2 mL/min, and urine inulin concentration is 9 μg/mL, what is GFR? A. 90 mL/min B . 45 mL/min C. 100 mL/min D. None of the above are correct. 52) Which of the following is the most permeable to water a. thin ascending loop of Henle b. distal convoluted tubule c.thin descending loop of Henle d. cortical portion of collecting tubule e. thick ascending limb of the loop of Henle 53) the major function of intercalated cells at the distal tubule? a) Reabsorb NaCl and water, secrete K+. b) Secrete Na+ and Ca++. c) Reabsorb water, secrete NaCl. d) Secrete H+ or reabsorb HCO3-. e) Reabsorb K+, secrete Na+.
