RAAS Pathway

Question 1

step 1

Answer 1

Stimulus - Low BP and/or SNS activation

Question 2

step 2

Answer 2

JG apparatus senses stimulus

Question 3

step 3

Answer 3

JG apparatus releases Renin into blood

Question 4

step 3.5

Answer 4

In the meantime, the liver is producing and releasing angiotensinogen

Question 5

step 4

Answer 5

Renin enzyme transforms angiotensinogen to ANG I

Question 6

step 5

Answer 6

ACE produced in the lungs and held in the endothelium transforms ANG I to ANG II (the active form)

Question 7

step 6

Answer 7

ANG II binds to receptors

Question 8

4 Receptors of ANG II

Answer 8

Systemic blood vessels
Kidneys
Hypothalamus
Adrenal Cortex

Question 9

Effect of ANG II on systemic blood vessels

Answer 9

Systemic blood vessels: vasoconstriction causing increased peripheral resistance causing increased BP

Question 10

Effect of ANG II on kidneys

Answer 10

Decreases GFR causing decreased urine output leading to increased volume leading to increased BP

Question 11

Effect of ANG II on adrenal cortex?

Answer 11

Release aldosterone which increases Na+/H2O reabsorption into blood, causing maintenance of blood volume and BP

Question 12

Net effect of ANG II

Answer 12

Increase BP

Question 13

What type of feedback loop?

Answer 13

Negative: increased BP stops low BP stimulus