CVS control Flashcards
1
Q
what causes renin release
A
- increase sympathetic stimulation
- decrease P in afferent arteriole
- decrease macula densa NaCl delivery
2
Q
actions of angiotensin 2
A
- arteriolar vasoconstriction
- increase aldosterone
- increase proximal tubule Na+ reabsorption
- increase sympathetic activity
- increase ADH release
3
Q
osmoreceptors
A
- in hypothalamus
- sense changes in effective plasma osmolality by altering volume
- changes synthesis & release of ADH by post. pituitary
4
Q
peripheral chemoreceptors
A
- in carotid sinus (carotid body), aortic arch (aortic body)
- increased firing from low PaO2
- stimulating increase RR, increase sympathetic drive to heart, vessels
- chemoreceptors are hyperactive in some hypertensive patients
(baseline PaO2 normal)
5
Q
extrinsic factors of the cardiovascular control system
A
neural
- PNS
- SNS
endocrine
- Adr
- RAAS
- ADH
- NP
6
Q
cardiac receptors
A
- vagal afferents sense change in cardiac volume
- linear increase in nerve activity with left atrial P
7
Q
response to increased BV
A
- increase HR
- decreased renal sympathetic stimulation (increased diuresis)
- also change ADH secretion by projection to hypothalamus
8
Q
systemic arterial baroreceptors
A
- mainly in carotid sinus, aortic bodies
- sense changes in pressure
- rapid resolution to homeostasis
9
Q
arterial baroreflex
A
afferents = carotid sinus nerve & aortic depressor nerves
efferents = sympathetic & vagal nerves
in hypertension, baroreflex is not as responsive
10
Q
baroreflex in BP drop
A
- increase HR, inotropic state
- increase constriction of pre-capillary resistant vessels (not cerebral or coronary)
- venoconstriction
- increased catecholamine release (adrenal medulla)
- increase ADH, angiotensin 2
11
Q
arterial baroreflex pathway
A
- baroreceptor inputs -> NTS -> PVN:
- > post. pituitary -> modulation of ADH secretion
- > RVLM -> sympathetc drive to vessels
