Secretion of Hydrogen Ion by the PCT is by the Process

Question

Secretion of hydrogen ion by the PCT is by the process of
A) diffusion.
B) facilitated diffusion.
C) active transport.
D) cotransport.
E) countertransport.

Accepted Answer

Hydrogen ions are secreted by the proximal convoluted tubule (PCT) through countertransport, specifically via the Na+/H+ exchanger, where sodium ions are reabsorbed while hydrogen ions are secreted into the tubular fluid.