Kidney function Knowledge-Based Download PDF

Questions

1. 1.

   Which cellular response is directly triggered in the nephron's collecting duct when circulating levels of antidiuretic hormone (ADH) increase?

   • A) Downregulation of sodium-potassium pumps along the basolateral membrane
   • B) Insertion of aquaporin-2 water channels into the apical membrane
   • C) Inhibition of active sodium reabsorption across the tubular epithelium
   • D) Direct constriction of the afferent arteriole to halt tubular flow
2. 2.

   In the mammalian nephron, what is the primary function of the countercurrent multiplier mechanism generated by the loop of Henle?

   • A) To establish an osmotic concentration gradient in the renal medulla that facilitates water reabsorption from the collecting duct
   • B) To prevent the filtration of large plasma proteins and blood cells across the glomerular basement membrane
   • C) To synthesize urea from ammonia and carbon dioxide within the tubular lumen
   • D) To actively transport glucose and amino acids from the renal pelvis back into the renal cortex
3. 3.

   Which process in the nephron selectively moves substances such as potassium ions, hydrogen ions, and certain metabolic drugs from the peritubular capillary blood directly into the renal tubule?

   • A) Glomerular filtration
   • B) Passive reabsorption
   • C) Countercurrent exchange
   • D) Tubular secretion
4. 4.

   Which factor primarily provides the driving force for the ultrafiltration of fluid from the blood into Bowman's capsule in the human kidney?

   • A) Glomerular capillary hydrostatic pressure
   • B) Capsular hydrostatic pressure
   • C) Blood colloid osmotic pressure
   • D) Active transport across the podocyte layer
5. 5.

   Which process in the nephron is responsible for recovering virtually all filtered glucose and amino acids from the tubular fluid back into the bloodstream under healthy conditions?

   • A) Tubular secretion in the distal convoluted tubule
   • B) Ultrafiltration across the glomerular capillaries
   • C) Selective reabsorption in the proximal convoluted tubule
   • D) Passive diffusion along the descending limb of the loop of Henle