Acid-base homeostasis · USMLE Step 1

Which organ is primarily responsible for long-term (hours to days) regulation of acid–base balance by modifying bicarbonate reabsorption and hydrogen ion excretion?

  1. Liver
  2. Heart
  3. Kidney
  4. Skin
Show answer and explanation

Correct answer: Kidney

The kidneys regulate acid–base balance in the long term by reabsorbing bicarbonate and secreting H⁺, thus adjusting plasma bicarbonate concentration.

Difficulty: Medium Question 4 of 19

Practice all 19 Acid-base homeostasis questions

Keep practicing

More Acid-base homeostasis questions