The Urinary System

1. 25 TheUrinary System

2. Which of the following is not a function of the kidneys? • Bile production • Excretion of excess ions • Release of erythropoietin • Activation of vitamin D

3. Urine collection occurs in the _______ of the kidney. • cortex • medulla • columns • pelvis

4. What fraction of the cardiac output is delivered to the kidneys each minute? • 1/1000 • 1/2 • 1/4 • 3/4

5. The blood-filtering structure of the kidney is called the __________. • glomerular capsule • renal tubule • glomerulus • nephron

6. The urine-forming units of the kidney are the __________. • glomerular capsules • renal tubules • glomeruli • nephrons

7. Based on the histology of a renal tubule, which section would be most severely inhibited if simple squamous epithelium were damaged? • Proximal convoluted tubule • Thin segment of the loop of Henle • Thick segment of the loop of Henle • Distal convoluted tubule

8. The vasa recta are associated with which structures in the kidney? • Glomeruli • Juxtamedullary nephrons • Afferent arterioles • Cortical nephrons

9. The juxtaglomerular apparatus is made of ______ cells from the afferent arteriole and the _________ cells of the DCT. • mesangial; filtration • filtration; mesangial • granular; macula densa • macula densa; granular

10. Which of the following factors contribute(s) to the higher filtration rate in the glomerular capillaries compared with other capillary beds? • The glomerular capillaries are fenestrated. • The diameter of the efferent arteriole is smaller than the diameter of the afferent arteriole. • The visceral layer of the glomerular capsule is very porous. • All of the above contribute.

11. Which of the following substances would not be found in normal filtrate? • Uric acid • Urea • Proteins • Creatinine

12. How would eating a high-protein diet affect filtration? • Due to higher colloid osmotic pressure in the glomerular blood, the net filtration pressure would be lower and less filtrate would form. • Too much protein in the diet would abolish all filtration. • High blood pressure from increased plasma proteins would increase filtration to twice its normal rate. • Filtration would be unchanged, but the kidneys would suffer damage.

13. What type of response by the afferent arterioles would you expect if blood pressure increased? • The afferent arterioles would constrict. • The afferent arterioles would dilate. • The afferent arterioles would stimulate renin release. • The afferent arterioles would not respond to blood pressure changes.

14. Autoregulatory mechanisms are most effective: • for renin secretion. • when the arterial pressure drops below 80 mm Hg. • at releasing epinephrine. • when the arterial pressure is between 80 and 180 mm Hg.

15. Extrinsic controls regulate glomerular filtration rate as a means of regulating ________. • systemic blood pressure • cardiac output • urine formation • red blood cell production

16. Which of the following general functions can be assigned to the renin-angiotensin system? • Water conservation • Blood pressure elevation • Lowering blood sodium levels • Both a and b

17. Of the filtered solutes, what percentage is reabsorbed by the renal tubule? • 1% • 50% • 99% • 100%

18. What would be the effect on urine output if sodium channels in the tubule cells were inhibited? • The volume would increase. • The volume would decrease • The volume would decrease by half the sodium concentration. • The volume would decrease by one-tenth the sodium concentration.

19. Why is glucose in the urine an indicator of diabetes mellitus? • When blood glucose is very high, the filtered glucose occupies all the transport carriers and it is no longer reabsorbed. • Because diabetics cannot regulate their glucose. • When blood glucose is low, it is excreted in the urine. • Because diabetics have high levels of glucagon.

20. Why do high levels of potassium stimulate aldosterone secretion? • Aldosterone stimulates potassium secretion at potassium-specific pumps. • Aldosterone stimulates the sodium-potassium pump to reabsorb sodium while simultaneously secreting potassium. • Aldosterone stimulates the sodium-potassium pump to secrete sodium while simultaneously reabsorbing potassium. • High levels of potassium accompany high levels of sodium.

21. Which of the following processes in urine formation is important for regulating blood pH? • Secretion • Reabsorption • Filtration • Countercurrent multiplication

22. Drinking too much alcohol results in a headache the next day. Why does this happen? • Alcohol stimulates pain receptors in the brain. • Alcohol stimulates sodium reabsorption. • Alcohol stimulates aldosterone secretion. • Alcohol inhibits ADH secretion.

23. Why is the osmolarity of medullary fluid in the kidney almost four times higher than the osmolarity of plasma? • The loop of Henle acts as a countercurrent multiplier and contributes solutes to the interstitial fluid. • Urea is recycled from the collecting duct and is transported to the interstitial fluid. • The medullary cells in the kidney synthesize solutes to establish the high osmolarity. • Both a and b occur.

24. How does ADH contribute to the formation of concentrated urine? • ADH increases the permeability of the ascending limb of the loop of Henle to water. • ADH increases the permeability of the descending limb of the loop of Henle to water. • ADH increases the permeability of the collecting duct to water by stimulating the insertion of aquaporins into the luminal membrane. • ADH decreases the permeability of the collecting duct to water by inhibiting the insertion of aquaporins into the luminal membrane.

25. What role do the vasa recta play in urine formation? • The vasa recta create the medullary osmotic gradient. • The vasa recta protect the medullary osmotic gradient by preventing rapid removal of salt. • The vasa recta receives the dilute filtrate from the distal convoluted tubule. • The vasa recta deliver urea to the medullary interstitial fluid

26. When considering drug administration, why is it important to know the renal clearance rate of the drug? • It dictates the dosage and frequency of administration of drugs. • It denotes how often drugs are recycled in the kidney. • It is used to determine the healing rate of an infection. • All of the above are factors in renal clearance rate.

27. Which of the following constitutes the largest solute component of urine? • Sodium • Potassium • Urea • Creatine

28. A patient feels radiating pain from the side of her body to the anterior abdominal wall. An MRI shows a bulging renal pelvis. Which is the most likely cause? • A kidney stone lodged in the ureter • A bacterial infection • Lack of blood flow to the kidney • An overflow of blood to the kidney

29. What features of the bladder predispose it to being able to stretch and relax repeatedly? • The wall contains smooth muscle. • The trigone acts as a spring when the bladder empties. • The walls are highly folded into rugae and the epithelium is transitional. • When emptied, the digestive viscera compress the bladder.

30. The process of voiding the bladder is called ______. • micturition • the urethral reflex • detrusor activation • incontinence

31. What is the functional difference between a male urethra and a female urethra? • Males have three urethral sphincters. • The male urethra is shared with the reproductive system. • The male urethra is connected to the renal pelvis. • The female urethra is much longer than a male’s.