Hypertension Flashcards
RAAS: what does it stand for
renin angiotensin aldosteron system
- regulates longterm bp and extracellular fluid
- activated when loss of blood volume ot drop in bp
RAAS explained
1) angiotensinogen is released from liver which stimulates the release of renin from kidneys
2) angiotensinogen + renin = angiotensin I
3) angiotensin I causes ACE to be released from lungs
4) angiotensin I + ACE = angiotensin II
5) angiotensin II causes adrenal gland to release aldosterone, adrenal gland also causes vasoconstriction
what does aldosterone do
- increase the reabsorption of Na, water sucks so bp inc
when is angiotensinogen released
low bp and changes in blood volume (usually response to changes in Na levels)
what stimulates the kidneys to release renin
low fluid volume
what does the release of renin cause
the liver to convert angiotensinogen to angiotensin I
what does angiotensin I do
travels to lung where its converted into angiotensin II by ace
what converts angiotensin I to II
ACE: angiotensin converting enzyme
what does angiotensin II act on
the adrenal gland which will release aldosterone
angiotensin II is a _____ ____
potent vasoconstrictor
RAAS can also be activated by…
- decreased renal perfusion
- pathologic ways
- some have hypersensitivity to angiotensin II or high secretors of renin
- stress can elevate angiotensin II, stimulates renin
other mechanisms that stimulate bp
- baroreceptors: found in the carotid sinus, aorta and LV that sense BP and will alter HR accordingly; can also impact vasocon/dil
- vascular auto regulation: helps maintain consistent levels of tissue perfusion, regulates mean arterial pressure, alters resistance, helps keep consistent BP at tissue level
primary HTN
- aka essential HTN
- occurs when there is no known cause (no underlying disease)
- occurs due to complicated interactions of genetics and env, involving neurohormonal effects
risk factors for primary HTN
- smoking
- excessive Na intake
- sedentary lifestyle
- hyperlipidemia
- stress
- fam history/genetics
- obesity / insulin resistance
- over the age of 60
- blacks
- high alc consumption
- men more likely before age 55
secondary HTN
known cause of HTN, known underlying disease
- treatment = treat underlying disease like
– renal disorders, adrencortical tumors, adrenomedullary tumors, drugs (oral contraceptives, corticosteroid, cocaine)
