The region of a nephron where P cells (principal cells) are located is:: (A) PCT, (B) Loop of Henle, (C) DCT, (D) Collecting duct
Answer is D. Collecting ducts have 2 cell populations: P cell / principle cell: Reabsorb Na+Secrete K+ Intercalated cell: Absorb K+Secrete H+, HCO3- it is the buffering cell in the kidney.