RAAS

Question 1

RAAS

Answer 1

-regulates blood volume and systemic vascular resistance, AND therefore CO and MAP

Question 2

Juxtaglomerular cells

Answer 2

-associated with afferent renal artery
-primary site for renin release

Question 3

When is renin released?

Answer 3

1.MAP decreases, renin is then released
2.Sympathetic stimulation increases renin release
3.decrease in NaCL concentration in distal tubule leads to increases in renin release

Question 4

What does renin do?

Answer 4

-Renin converted to Angiotensin I by angiotensinogen
Angiontensin I converted to angiontensin II by angiotensinogen converting enzyme

Question 5

What does Ang II do?

Answer 5

-increase in vasoconstriction, therefore increase in SVR and MAP
-increased Na and H2O retention, therefore increase in CO and MAP
-increase in aldosterone and therefore ADH (vasopressin) resulting in less water loss and therefore urination
-increased thirst
-increased adrenergic signaling

Question 6

Counter-regulation of RAAS

Answer 6

-RAAS works to increase blood volume and therefore increase preload. A large increase in blood volume in the heart over time will lead to cardiac distention (increased blood volume)
-Cardiac distention leads to increased sympathetic stimulation and Ang II
-An increase in RAAS activation components leads to an increase in brain and atrial naturietic peptides (BNP, ANP) released from the heart

Question 7

What does BNP and ANP target?

Answer 7

-Veins: increased vasodilation, decrease central venous pressure, preload, and CO
-Arteries: increase vasodilation, decrease SVR and MAP
-Kidneys: increase glomerular filtration rate, decreases Na and H2O retention, CO, and MAP
-Kidneys: decrease renin release, and therefore Ang II leading to decreasing RAAS
**Reduce pressure!!

Question 8

What does high levels of BNP and ANP mean?

Answer 8

-heart failure