61.  The proximal convoluted tubule is  
A.  lined with epithelial cells that lack microvilli.
B.  the site of glucose and amino acid reabsorption.
C.  permeable to water if ADH is present.
D.  impermeable to water.
E.  the site of water secretion.

62.  Arrange the following in correct order.
(1) cotransport molecule binds to sodium and glucose
(2) establish sodium concentration gradient between tubular cells and tubular lumen
(3) sodium and glucose moved into tubular cell
(4) active transport of sodium from tubular cells to interstitial area  
A.  2, 1, 3, 4
B.  4, 2, 1, 3
C.  1, 3, 4, 2
D.  2, 4, 1, 3
E.  1, 2, 3, 4

63. Glucose is usually completely reabsorbed from the filtrate by the time the filtrate has reached the 
A. tip of the loop of Henle.
B. end of the collecting duct.
C. end of the distal convoluted tubule.
D. end of the proximal convoluted tubule.
E. beginning of the proximal convoluted tubule.

64.  Water reabsorption by the renal tubules uses  
A.  active transport.
B.  cotransport.
C.  solvent drag.
D.  osmosis.
E.  None of these choices is correct.

65.  In the ascending limb of the loop of Henle,  
A.  water can easily enter or leave.
B.  potassium and chloride are cotransported with sodium across the apical membrane.
C.  calcium ions are actively transported across the basal membrane.
D.  potassium is concentrated in the filtrate.
E.  the filtrate does not change.

66.  Once inside the cells of the ascending limb, potassium and chloride cross the basal membrane into the interstitial fluid by the process of  
A.  facilitated diffusion.
B.  cotransport.
C.  counter transport.
D.  active transport.
E.  simple diffusion.

67. Which of the following ions are cotransported across the wall of the proximal convoluted tubule, distal convoluted tubule, and the ascending limb of the loop of Henle? 
A. sodium and bicarbonate
B. potassium and phosphate
C. sodium and chloride
D. bicarbonate and potassium
E. potassium and chloride

68. The collecting ducts and distal convoluted tubules 
A. reabsorb glucose.
B. collect filtrate from Bowman’s capsule.
C. actively transport sodium ions but not chloride ions.
D. vary in their permeability to water relative to the amounts of ADH present.
E. do not alter their permeability to water.

69.  The collecting duct becomes more permeable to water when  
A.  colloid osmotic pressure increases.
B.  ADH production increases.
C.  plasma osmolality decreases.
D.  aldosterone production decreases.
E.  ADH production decreases.

70.  As ADH production declines,  
A.  glomerular filtration increases.
B.  potassium reabsorption increases.
C.  reabsorption of water increases.
D.  the urine volume increases.
E.  the blood volume increases.