Distal tubule

Question 1

What is the function of the distal tubule?

Answer 1

For alterations of the filtrate. It reabsorbs 5% of NaCl and water, to bring the filtrate back to an isotonic state.

Question 2

What ions can be secreted in this tubule for alterations?

Answer 2

K and H

Question 3

How is Na transported in the distal tubule?

Answer 3

In early DT it uses Na/Cl cotransporter

In the late DT it uses ENAC.

Question 4

What is the function of thiazides?

Answer 4

A thiazide diuretic blocks NCC on the apical membrane to prevent Na and H2O reabsorption. Used as an antihypertensive.
S.E. include Increased uric acid, hyperglycaemia and hyponatraemia.

Question 5

What controls ENAC?

Answer 5

Aldosterone regulates for volume control.

Question 6

What does aldosterone do?

Answer 6

Stimulates the synthesis of ENAC and NA/K ATPase to increase reabsorption of water to increase plasma volume.

Question 7

What inhibits ENAC?

Answer 7

Amiloride