Regulation of Arterial Pressure Flashcards
What comprises the afferent component of short term arterial pressure regulation?
arterial baroreceptor reflex in the carotid and aorta
How do the arterial receptors initially respond to a decrease in blood pressure? over a long period of time?
decreased firing activity,
they adapt and return to the “normal” baseline firing rate
What comprises the efferent component of the short term arterial pressure regulation?
the SNS and PNS
What is the role of the medulla in the baroreceptor reflex?
coordinating the afferent and efferent components to adjust HR and vascular resistance
What is the goal of carotid massage?
To simulate an increase in pressure in the carotid artery, increasing firing rate of the carotid baroreceptor to activate the PNS and kick someone out of a-fib
The cushing reflex, decreased pO2 and increased pCO2, exercise, emotional excitement, central command input, cutaneous pain, and vasoconstriction for heat conservation have what affect on arterial pressure?
they all increase MAP
How do the cardiopulmonary baroreceptors keep the arterial pressure low/homeostatic?
they have a tonic inhibitory affect on the SNS
What is the Cushing reflex?
the increase in arterial pressure with an increase in ICP (to ensure adequate perfusion in the case of an obstruction causing ICP)
What is the dive reflex?
a reflex triggered by cold water on the face that decreases HR (bradycardia-PNS) and causes vasoconstriction (SNS) everywhere but the heart and brain to decrease O2 metabolism and allow to stay underwater longer
Describe the mechanism for vasovagal syncope
an event triggering activation in the medulla decreases SNS input (vasodilation) and greatly increases PNS input (bradycardia, decreased cardiac contractility)
What is the affect of deep pain on arterial pressure?
decrease in SNS and increase in PNS cause a decrease in arterial pressure such as in cases of shock
Which has more impact on arterial pressure: temperature or exercise?
temperature
(hypothalamus to SNS to cutaneous vessels; overheated -> vasodilation and decreased MAP, hypothermic -> vasoconstriction and incrased MAP
What controls the long term regulation of arterial pressure?
the fluid balance maintained by the kidneys
Explain how urinary output can be a negative feedback loop in controlling MAP
increased MAP-> increased urinary output-> decreased blood volume-> decreased CO-> decreased MAP
glomerular filtration rate subtracted from the renal fluid reabsorption rate will give you what?
the urinary output rate
