Arterial BP Regulation--Nordgren Flashcards
Afferent pathway: baroreceptor reflex
sensor location
aortic arch
carotid arteries
Wha type of receptors are arterial baroreceptors?
mechanoreceptors
What happens when baroreceptors are stimulated too long (forgeting long term pressure regulation)?
become desensitized
Where is the central integration of the baroreceptor reflex located?
medulla
we don’t really know its mechanism, though
How do you affect mean arterial pressure?
2 mechanisms
peripheral resistance
cardiac output (Q)
Cardiopulmonary baroreceptors
function
tonic inhibitory influences
Berzhold-Jarisch decompressor reflex
causes bradycardia and hypotension
especially in MI
Chemorececeptor reflexes
depending on P02 and PCO2
Cushing Reflex
rise in intercranial pressure will increase arterial pressure
prevent collapse of cranial vessels
Exercising skeletal muscle
reflex tachycardia
cortical centers that lead to skeletal muscle contration during exercise also lead to tachycardia and tachypnea
Dive Reflex
bradycardia and vasoconstriction in all organs except brain and heart
when diving
prolongs how long person is able to be submerged, decreased O2 consumption
What is unique to dive reflex
parasympathetic –> heart
sympathetic –> peripheral vascular system
Emotion-Blushing Reflex
selective loss of sympathetic tone
Vasovagal Syncope
sudden dramatic loss of sympathetic tone
increased parasympathetic activity
Central Command
cortical input
Pain effect on arterial pressure
+ or - effect
superficial pain: + BP
deep pain: - BP
–> part of shock mechanism in serious injuries
Major electrolyte in fluid control
Na+
What is the mechanism responsible for low BP in some cases of MI?
cardiopulmonary baroreceptors
atria, ventricles, coronary arteries, lungs
RAAS in blood pressure control
renin –> angiotensin –> aldosterone
system
What enzymes function to convert RAAS products?
renin
angiotensinogen –> angiotensin I
ACE
angiotensin I –> angiotensin II
angiotensin II causes release of aldosterone
aldosterone –> Na+ absorbtion
Vasopressin/ADH is released by…
posterior pituitary
How does BP affect urine production?
high BP –> high urine output