RAAS Flashcards
The capacity of the kidney to completely return BP to normal via augmented urine volume and sodium excretion
Pressure natriuresis
High BP that is attributed to an unknown cause
Essential Hypertension
High BP that is attributed to a definable causes
Secondary Hypertension
an inflammatory mediator; a peptide that causes blood vessels to dilate, and therefore causes blood pressure to fall
Bradykinin
part of the arterial circulation that is responsible for organ perfusion
Effective Arterial Blood Volume
If Effective Arterial Blood Volume falls, the kidneys…
retains Na and H2O
Factors that can reduce Effective Arterial Blood Volume
Dec. Volume (Hemorrhage, Dehydration)
Inc. Vascular Capacitance (Cirrhosis, Sepsis)
Reduced CO (CHF)
Proteolytic enzyme made by kidney; converts angiotensinogen to angiotensin 1; produced in the juxtaglomerular apparatus
Renin
Site of renin production; modified smooth muscle cells located in the media of kidney afferent arterioles
juxtaglomerular apparatus
What stimulates renin release
Dec. effective circulating volume
octapeptide derived from cleavage of the C-terminal peptide on Angiotensin I by ACE; stimulates arteriolar vasoconstriction and aldosterone release
Angiotensin II
Enzyme found on endothelial cells; catalyzes A1 to A2; converts bradykinin to inactive metabolites; inhibitors are important in treating HTN and HF
Angiotensin Converting Enzyme (ACE)
What does ACE do (2 roles)
Converts Angiotensin I to II
Breaks bradykinin into inactive metabolites
aldosterone cause the retention of…
Na and H2O
RAAS
Renin-Angiotensin-Aldosterone System
Rate Limiting Step in RAAS
Renin cleaving Angiotensinogen
Most individuals with primary HTN have increased ________
Renin
Those with (low/high) renin hypertension have a good response to diuretics and calcium channel blockers
Low
Chronic Kidney Disease and Renal Artery Stenosis cause (decreased/increased) renin, stimulating increased aldosterone
Increased (due to low effective arterial blood volume?)
Why does primary aldosteronism not result in increased renin?
Otherwise known as Conn’s Syndrome, you already have plenty of Aldosterone being produced, so no renin needed
Why does CHF result in RAAS stimulation?
Decreased CO and peripheral vascular resistance cause dec. EABV
RAAS activation contributes to the pathogenesis of what two medical conditions
HTN
HF
