Endo 7

Question 1

Physiological roles of aldosterone

Answer 1

• increases Na reabsorption by the kidney microtubules, conserving Na
• reduced K reabsorption- increased K loss
• retaining Na causes water retention

Question 2

Site of action for aldosterone

Answer 2

DT and CD

Question 3

Renin-agniotensinogen system

Answer 3

• each nephron has a JG apparatus associated with the distal tubule and the glomerulus
• the JG comprises sensory cells (MD) in the wall of the DT of the nephron and associated secretory cells that release the enzyme renin

Question 4

Renin

Answer 4

Renin acts on angiotensinogen and catalyzes the formation of angiotensin I which is then converted to angiotensin II by ACE

Question 5

Two receptor types for ADH/Vasopressin

Answer 5

V1A-vasoconstriction
V1B-ACTH secretion
V2-decreased urine production, increased salt and water reabsorption

Question 6

ADH

Answer 6

central or nephrogenic
symptoms: polyuria (excessive watery urine) followed by polydipsia (increased thirst)
Diagnosis and treatment: pitressin and desmopressin

Question 7

ANP

Answer 7

• produced by cardiomyocytes of the RA
• functionally antagonizes the RAS-aldosterone system
• defends against corticoid-and diet-related salt retention
• inhibts renin secretion from JGA
• inhibits aldosterone directly
• decreases salt appetite

Question 8

Effects of catecholamines secreted by the adrenal medulla

Answer 8

increased blood glucose levels
increased BMR
increased glucose release from liver
increased glycolysis in liver and muscle