Renin angiotensin aldo system

Question 1

Angiotensinogen -> angiotensin I

Answer 1

Angiotensinogen (made in liver) converted by

Renin in kidney

Question 2

What induces renin from kidney

Answer 2

1) Low BP by JG cells
2) Low Na+ delivery to MD cells
3) Increased sympathetic tone by beta 1 receptor

Question 3

Angiotensin I to angiotensin II

Answer 3

ACE (made in lung)

ACE also degrades bradykinin

Question 4

Where does angiotensin II work?

Answer 4

1) AT1 on vascular smooth muscle
2) Efferent glomerulus
3) Adrenal gland
4) Posterior pit
5) Proximal tubule
6) Hypothalmus

Question 5

Angiotensin II at vascular smooth muscle

Answer 5

Work on AT1 receptor,
Vasoconstriction,
Increases BP

Question 6

Angiotensin II at efferent arteriole of glomerulus

Answer 6

Constricts efferent
Increase FF to preserve renal function GFR
in low volume state (when RBF is low)

Question 7

Angiotensin II at adrenal glands

Answer 7

Increase aldo secretion, which then
increases Na+ channel and Na+/K+ pump insertion in principal cells

This enhances K+ and H+ secretion
(upregulates K+ channel on principal and H+ on intercalated cell)

Creates favorable gradient for Na+ and water reabsorption

Question 8

Angiotensin II at posterior pituitary

Answer 8

Increases ADH secretion, which then
increases H2O channel insertion in principal cells
increases H2O reabsorption

Question 9

Angiotension II at proximal tubule

Answer 9

Increases Na+/H+ antiporter activity,
so increases Na+, bicarb, and water reabsorption.
(can permit contraction alkalosis)

Question 10

Angiotensin II at hypothalamus

Answer 10

Stimulates thirst