RAAS Flashcards
RAAS stands for
Renin Angiotensin Aldosterone System (RAAS)
What does the Renin Angiotensin Aldosterone System (RAAS) regulate
System that is essential for the regulation of blood pressure and fluid balance
What are the 3 hormones used in the Renin Angiotensin Aldosterone System (RAAS)
Renin
Angiotensin II
Aldosterone
Where is renin produced
Renin is a proteolytic enzyme released by granular cells of the juxtaglomerular apparatus, formed by the distal convoluted tubule and the glomerular afferent arteriol
Which cells of the juxtaglomerular apparatus releases renin
Granular cells
The juxtaglomerular apparatus releases renin in response to
Reduced blood pressure
How is the juxtaglomerular apparatus able to detect the blood pressure in order to detect whether it is low to release renin
Detects the blood pressure by:
- Renal artery hypotension
- Sympathetic stimulation
- Reduced sodium levels in the distal tubal
What is the function of renin
Renin acts in the blood cleaving angiotensinogen into angiotensin I
Where is Angiotensin-converting enzyme (ACE) found
Angiotensin-converting enzyme (ACE) are found primarily in the vascular endothelium of the lungs
What is the function of Angiotensin-converting enzyme (ACE)
Cleaves angiotensin I to angiotensin II
What is the function of Angiotensin II
Stimulates adrenal cortex to release aldosterone
Causes vasoconstriction
Increases sodium reabsorption
Stimulates the release of anti-diuretic hormone (ADH)
Increases sympathetic permissiveness
Aldosterone is an example of a _____
a) Mineralocorticoid
b) Glucocorticoid
a) Mineralocorticoid
Where is aldosterone produced and secreted
Aldosterone is a mineralcorticoid
It is produced and secreted by the zona glomerulosa of the adrenal cortex
In response to what, does the zone glomerulosa release aldosterone
Angiotensin II (primary stimulus)
ACTH
High serum potassium
What is aldosterone’s primary action in the RAAS system
Aldosterone’s primary action is to upregulate epithelial sodium channels (ENaC) in the kidneys, primarily the collecting duct and late distal tubules.
The sodium channels causing sodium influx into the cells.
The sodium channels cause sodium and water reabsorption and obligatory loss of potassium. Thereby, restoring salt levels and blood pressure.
