Moderate

Water and sodium ions are reabsorbed in:

Correct answer: D. Proximal Convoluted Tubule & Collecting Duct

  • A. Urinary Bladder and Urethra
  • B. Ureter
  • C. Adrenal Cortex
  • D. Proximal Convoluted Tubule & Collecting Duct

Explanation

The majority of water and sodium ion reabsorption occurs in the proximal convoluted tubule (PCT) of the nephron. Additional fine-tuning of water reabsorption (under ADH influence) happens in the collecting duct. The bladder and ureter are involved in urine storage and transport, not reabsorption. The adrenal cortex produces hormones like aldosterone (which affects sodium reabsorption) but is not a site of direct reabsorption.

Last updated

About Homeostasis

Homeostasis maintains a stable internal environment through the kidney and urinary system, thermoregulation and excretion. The kidney topics include filtration, selective reabsorption, urine formation and water balance, while thermoregulation involves sweating, vasodilation, vasoconstriction and hormonal control; excretion is different from egestion, which removes undigested food.

Practise Homeostasis

698 free Homeostasis MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Biology questions like this

Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions