Renin-Angiotensin-Aldosterone System (RAAS)

Question 1

Where is renin secrted from

Answer 1

juxtaglomerular kidney cells

Question 2

What do juxtaglomerular kidney cells do?

Answer 2

sense changes in renal perfusion pressure, via stretch receptors in the vascular walls.

Question 3

What happens when the renal perfusion drops and what does it stimulate?

Answer 3

Renin is released into the circulation by the kidneys. It stimulates the formation of angiotensin 1 and 2, causing vasoconstriction.

Question 4

What does vasoconstriction stimulate?

Answer 4

the release of vasopressin (antidiuretic hormone, ADH) from the posterior pituitary, which increases fluid retention by the kidneys

Question 5

What two other things that RAAS stimulates?

Answer 5

thirst centres within the brain

cardiac hypertrophy and vascular hypertrophy

Question 6

What do all of these mechanisms act to increase?

Answer 6

increase systemic blood pressure and renal perfusion.