Hypertension Flashcards
There are three primary stimuli for renin secretion:
(1) decreased NaCl transport in the distal portion of the thick ascending limb of the loop of Henle that abuts the corresponding afferent arteriole (macula densa)
(2) decreased pressure or stretchwithin the renal afferent arteriole (baroreceptor mechanism)
(3)sympathetic nervous system stimulation of renin-secreting cells via β1adrenoreceptors.
renin secretion is inhibited by:
increasedNaCl transport in the thick ascending limb of the loop of Henle,
by Increased stretch within the renal afferent arteriole
by β1 receptorblockade.
is a potent pressor substance, the primary tropic factor for the secretion of aldosterone by the adrenal zona glomerulosa.
angiotensin II
the secretion of aldosterone by the
adrenal zona glomerulosa
May play a role in the pathogenesis of atherosclerosis through a direct cellular action on the vessel wall
angiotensin II
The____ induces vasodilation, sodium excretion, and inhibition of cell growth and matrix formation.
Experimental evidence suggests that these receptor improves vascular remodeling by stimulating smooth muscle cell apoptosis and contributes to the regulation of glomerular filtration rate
AT2 receptor
True or false:
AT 1 receptor blockade induces an increase in AT2 receptor activity
True
Renin-producing carcinomas also have been described in
lung, liver, pancreas, colon, and adrenals.
In addition to regulating local blood flow, tissue ___ is a mitogen that stimulates growth and contributes to modeling and repair.
Excess tissue ______ may contribute to atherosclerosis, cardiac hypertrophy, and renal failure, and consequently may be a target for pharmacologic therapy to prevent target organ damage.
angiotensin II
is the primary tropic factor regulating the synthesis and secretion of aldosterone by the zona glomerulosa of the adrenal cortex.
Angiotensin II
True or false:
ACTH is not an important tropic factor for the chronic regulation of aldosterone
True
True or false:
Aldosterone synthesis is also dependent on potassium, and Aldosterone secretion may be decreased in potassium-depleted individuals.
True
True or false
ACTH is an important tropic factor for the chronic regulation of aldosterone.
False
ACTH is not an important tropic factor for the chronic regulation of aldosterone.
Which of the following is true:
- Increased activity of the renin-angiotensin-aldosterone axis is associated with hypertension
- In patients with CHF, low-dose spironolactone reduces therisk of progressive heart failure and sudden death from cardiac causesby 50%.
- Secondary aldosteronism (i.e., increased aldosteronesecondary to increased renin-angiotensin), but not hypertension, also isobserved in edematous states such as CHF and liver disease.
Number 3.
- Increased activity of the renin-angiotensin-aldosterone axis is not invariably associated with hypertension
- In patients with CHF, low-dose spironolactone reduces therisk of progressive heart failure and sudden death from cardiac causesby 30%.
Noninvasive determination of pulse wave velocity between the ___ & ____ arteries is often interpreted as an index of arterial stiffness.
carotid and femoral
a surrogate index of arterial stiffening, is calculated as the ratio of central arterial pressure-to-pulse pressure.
aortic augmentation index,
True or false:
Central blood pressure also appears to be more stronglyassociated with pre-clinical organ damage than brachial blood pressure
True
Ion transport by vascular smooth muscle cells may contribute tohypertension-associated abnormalities of vascular tone and vascular growth, both of which are modulated by
intracellular pH (pHi).
Three ion transport mechanisms participate in the regulation of pHi:
(1) Na+-H+ exchange, (2) Na+-dependent HCO3–-Cl– exchange, and(3) cation-independent HCO3–-Cl– exchange
Na+-H+ exchanger is increased in hypertension, hence increased sodium entry may lead to increased vascular tone by activating Na+-Ca2+ exchange and thereby increasing
intracellular calcium
True or false
Endothelium-dependent vasodilation is impaired in hypertensive patients.
True
is a vasoconstrictor peptideproduced by the endothelium, and orally active endothelin antagonistsmay lower blood pressure in patients with resistant hypertension
Endothelin
True or false
Inflammation and alterations of the immune response have beenimplicated in the pathogenesis of vascular injury and hypertensionfor at least four decades
True
Inflammation,vascular stretch, angiotensin II, and salt have all been shown to result-in the generation of______, which modify T cellfunction and further enhance inflammation.
reactive oxygen species (ROS)