Question

1. the hormone adh promotes water reabsorption through the wall(s) of the a) proximal tubule and collecting duct b) distal tubule and collecting duct c) descending limb of the nephron loop d) ascending limb of the nephron loop 15) after eating, what hormone signals the hypothalamus to suppress appetite? a) neuropeptide y b) ghrelin c) pepsin d) leptin 16) what is the effect of secretion of atrial natriuretic peptide? a) increased potassium excretion b) increased sodium excretion c) decreased potassium excretion d) decreased sodium excretion 17) which choice describes the countercurrent mechanism of the nephron loop? a) water moves into the descending limb; sodium moves out of the descending limb b) water moves out of the descending limb; sodium moves out of the ascending limb c) water moves out of the ascending limb; sodium moves into the ascending limb d) water moves into the ascending limb; sodium moves out of the ascending limb

Explanation:

• Question 14: Antidiuretic hormone (ADH) acts on the distal tubule and collecting duct to increase water reabsorption.
• Question 15: Leptin is a hormone that signals the hypothalamus to suppress appetite after eating.
• Question 16: Atrial natriuretic peptide (ANP) promotes increased sodium excretion.
• Question 17: In the countercurrent mechanism of the nephron loop, water moves out of the descending limb (due to high osmolarity in the medulla), and sodium moves out of the ascending limb (active transport).

Answer:

1. B. distal tubule and collecting duct
2. D. Leptin
3. B. Increased sodium excretion
4. B. Water moves out of the descending limb; sodium moves out of the ascending limb