1. Which of these is the major functional unit of the kidney? a. The hilus b. The efferent arteriole

1. Which of these is the major functional unit of the kidney? a. The hilus b. The efferent arteriole c. The juxtaglomerular apparatus d. The nephron 2. Which of these urinary structures is involved in the countercurrent exchange mechanism? a. The afferent arteriole b. The efferent arteriole c. The vasa recta d. The juxtaglomerular apparatus