Distal Tubule and Collecting Ducts

Question 1

• What are the two important hormones which act on these sites?

Answer 1

Aldosterone (increases sodium reabsorption) & ADH (increases water reabsorption)

Question 2

• What determines the rate of K+ excretion?

Answer 2

Rate of K+ secretion in the distal convoluted tubule, stimulated by aldosterone

Question 3

• What does an increase in plasma [K+] stimulate?

Answer 3

Synthesis and secretion of aldosterone from the zona glomerulosa of the adrenal gland

Question 4

• What controls the water content of urine exiting CDs?

Answer 4

ADH