Question

Active transport of substances from the blood into the nephron is called _____.The movement of substances from the filtrate back into the blood in the peritubular capillaries is called _____.

• A. Filtration and back flow
• B. Tubular reabsorption and backflow​
• C. Tubular secretion and tubular reabsorption
• D. Tubular reabsorption and tubular secretion

Answer 1

The correct option is C

Tubular secretion and tubular reabsorption

Tubular secretion is the transfer of materials from peritubular capillaries to the renal tubular lumen and occurs mainly by active transport. It is the tubular secretion of H⁺ and NH₄⁺ from the blood into the tubular fluid that helps to keep blood pH at its normal level.