The main site of bicarbonate re-absorption is:: (A) Proximal convoluted tubule, (B) Distal convoluted tubule, (C) Coical collecting duct, (D) Medullary collecting duct
Answer is A. Proximal convoluted tubule is the main site of bicarbonate absorption. About 80 to 90 percent of bicarbonate re-absorption occurs in the proximal tubule. Ref:Textbook of Medical Physiology By Guyton, 10th Edition, Page 353