Excretory system Knowledge-Based Practice

Questions

1. 1.

   In the mammalian nephron, which characteristic accurately describes the thick ascending limb of the loop of Henle?

   • A) It is virtually impermeable to water and actively reabsorbs sodium and chloride ions into the medullary interstitium.
   • B) It is highly permeable to water via osmosis and passively reabsorbs urea into the bloodstream.
   • C) It relies on high hydrostatic pressure to filter large plasma proteins directly into the tubular lumen.
   • D) It actively secretes all filtered glucose and amino acids from the interstitium into the tubular fluid.
2. 2.

   In a healthy human kidney, which of the following substances is normally prevented from entering Bowman's capsule during glomerular filtration?

   • A) Amino acids
   • B) Urea
   • C) Sodium ions
   • D) Serum albumin
3. 3.

   Which hormone directly increases water reabsorption in the human excretory system by promoting the insertion of aquaporin channels into the membranes of the collecting ducts?

   • A) Aldosterone
   • B) Antidiuretic hormone
   • C) Angiotensin II
   • D) Atrial natriuretic peptide
4. 4.

   During urine formation in the human kidney, which process is primarily responsible for the active transport of substances such as hydrogen ions, potassium ions, and metabolic drug residues from the peritubular capillaries directly into the renal tubule?

   • A) Glomerular ultrafiltration
   • B) Facultative reabsorption
   • C) Countercurrent exchange
   • D) Tubular secretion
5. 5.

   During urine formation in the human kidney, which part of the nephron is responsible for reabsorbing virtually all filtered glucose and amino acids, as well as the majority of water and sodium ions?

   • A) Collecting duct
   • B) Distal convoluted tubule
   • C) Ascending limb of the loop of Henle
   • D) Proximal convoluted tubule

Answers and step-by-step solutions appear after you finish the test.