Regulation of arterial pressure Flashcards
what is the most rapid method of pressure control
neuronal through peripheral baroreceptors
what mediates the slower mediation of pressure
RAAS
what nerve innervates the carotid sinus
glossopharyngeal n (CN IX) aka the sinus nerve of hering
what innervates the aortic sinus
vagus n (CN X) and the aortic nerve
where do the nerves from the baroreceptors synapse
nucleus tractus solitarius (NTS)
what does the NTS use as its neurotransmitter
glutamate
what output from the NTS gives the vasculature response
rostral ventrolateral medulla
what output from the NTS gives the cardiac response
dorsal motor nucleus of the vagus and nucleus ambiguous
what receptor type is associated with baroreceptors
TRP channels
How do you calculate the MABP (mean arterial blood pressure)
HRSVTPR or CO*TPR
what 2 factors determine SV
sympathetic stim of heart and preload
what 2 factors affect HR
sympathetic and parasympathetic stim
how is the aortic receptor different from the carotid
aortic has higher threshold
for activation, continues to respond above
saturation, less sensitive to rate, less effected by
decreases
what are the upper and lower limits of the carotid body in regards to pressure
200 to 40-60 mm Hg
what does the sympathetic system cause in arterial pressure
decreased baroreceptor firing, preganglionic fibers below T1
what does the sympathetic innervate in the heart
heart muscles, SA node directly, vessels, and adrenal gland via splanchnic n
what receptor causes constriction of the arterioles and veins
alpha receptors
what receptor increases HR and contractility
beta 1
what does the parasympathetic system do to decrease heart rate
increased baroreceptor firing; vagus n signals SA, atria and vent; acts on muscarinic receptors; stimulates NO release in vessels
when is renin secreted
in response to a drop in BP
if BP is higher than normal, what does the body do
less renin is secreted
what form of angiotensin is active? what does it do
2; causes secretion of aldosterone from adrenal cortex
what does aldosterone do
leads Na and H2O retention by kidneys
causes increased blood volume, preload/stroke volume, CO, and BP
increased thirst
stimulates release of ADH
what does angiotensin II do for global vasculature
global vasoconstriction of arterioles by binding to AT1 receptors
increases TPR and BP
what is a side effect of ACE inibitors
cough because of bradykinin buildup
what is another way of blocking angiotensin 2 besides ace inhibitors
angiotensin receptor blockers
what does ADH cause
increase TPR and water retention
what does ADH act on
V1 receptors in SM and V2 receptors in collecting ducts
what causes increased secretion of ANP, BNP, or CNP
excessive preload of atria and ventricles
what do natriuretic peptide do
arteriolar dilation - decreases TPR
increases fluid loss - decreases preload
inhibits renin - decreases both TPR and preload
what is the cushing triad
hypertension (sympathetic) , bradycardia (baroreceptor), irregular respiration (impaired brainstem function)
what causes cushings triad
increased intercranial pressure
what are the responses to increased blood volume
- Increase secretion of ANP
- Decrease ADH secretions
- Renal vasodilation
- Increased heart rate
what are the general reactions to exercise
- Increased sympathetic output (beta-1 receptors) and decreased parasympathetic output
- Increased HR/contractility (you name it, it goes up)
- Increased venous return
- Vasoconstriction due to alpha1 receptor activation (overall slight increase in MAP)
- SBP will increase, DBP should not change much
