Renal control of Acids and Bases

Question 1

What is a normal urine pH range?

Answer 1

4.5-8.0

Question 2

What is main form of secreted H+ in the urine?

Answer 2

NH4+ (Ammonium)

Question 3

What cell in the collecting duct is responsible for HCO3- reabsorption?

Answer 3

A-intercalated cells

Question 4

What cell in the collecting duct is responsible for HCO3- secretion?

Answer 4

B-intercalated cells

Question 5

What is concentration at which HCO3- begins to be secreted in the urine?

Answer 5

> 26 mEq/L

Question 6

What are the two main actions of Aldosterone?

Answer 6

1) Increased Na+ reabsorption 2) Increase activity of H+ ATPase in the distal tubule (causing Alkalosis)

Question 7

Where is Inorganic phosphate primarily secreted?

Answer 7

It is secreted via A-intercalated cells in the late distal tubule/principal cell

Question 8

What are the two primary transports along the apical membrane of the A-intercalated cell?

Answer 8

1) H+ ATPase 2) H+/K+ Exchanger

Question 9

What is the destination of NH4+ secreted in the proximal tubule?

Answer 9

It is reabsorbed via Na+/K+/ 2 Cl- cotransport at the TALH

Question 10

What is the destination of the NH4+ that is produced at the late distal tubule/collectin duct?

Answer 10

It is excreted as NH4+

Question 11

What is the main mechanism of action regarding Angiotensin II?

Answer 11

It stimulates the Na+/H+ exchange in the PCT; plays a role in contraction alkalosis