25. The Urinary System

In which section of the nephron is the process of reabsorption influenced by hormones?

The distal convoluted tubule is an important site for 

(a) Active secretion of ions

(b) Active secretion of acids and other materials

(c) Selective reabsorption of sodium ions from the tubular fluid

(d) All of these

Ryan just ate a very protein-rich meal. Because of this, the amino acid levels in his blood currently exceed the transport maximum and the renal threshold for amino acids (65 mg/dL). What will happen to the excess amino acids?

Drugs that treat hypertension, or high blood pressure, have the following actions. Discuss the specific effect that each drug will have on the kidneys.

c. Blocking the Na+/Cl−/2K+ transport pumps in the thick ascending limb of the nephron loop

Trace the pathway taken by a molecule of urea through the kidney from the glomerulus to the renal pelvis if the urea is recycled.

Predict what would happen if the tubule wall of the descending limb suddenly lost all its aquaporins.

Sodium reabsorption in the DCT and in the cortical portion of the collecting system is accelerated by the secretion of 

(a) ADH

(b) Renin

(c) Aldosterone

(d) Erythropoietin

Which is reabsorbed by the proximal convoluted tubule cells?

a. Na⁺

b. K⁺

c. Amino acids

d. All of the above

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Sodium ions and glucose are cotransported into the proximal tubule cell by secondary active transport.