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Flashcards in Regulation of Arterial Pressure Deck (20)
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1
Q

What comprises the afferent component of short term arterial pressure regulation?

A

arterial baroreceptor reflex in the carotid and aorta

2
Q

How do the arterial receptors initially respond to a decrease in blood pressure? over a long period of time?

A

decreased firing activity,

they adapt and return to the “normal” baseline firing rate

3
Q

What comprises the efferent component of the short term arterial pressure regulation?

A

the SNS and PNS

4
Q

What is the role of the medulla in the baroreceptor reflex?

A

coordinating the afferent and efferent components to adjust HR and vascular resistance

5
Q

What is the goal of carotid massage?

A

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

6
Q

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?

A

they all increase MAP

7
Q

How do the cardiopulmonary baroreceptors keep the arterial pressure low/homeostatic?

A

they have a tonic inhibitory affect on the SNS

8
Q

What is the Cushing reflex?

A

the increase in arterial pressure with an increase in ICP (to ensure adequate perfusion in the case of an obstruction causing ICP)

9
Q

What is the dive reflex?

A

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

10
Q

Describe the mechanism for vasovagal syncope

A

an event triggering activation in the medulla decreases SNS input (vasodilation) and greatly increases PNS input (bradycardia, decreased cardiac contractility)

11
Q

What is the affect of deep pain on arterial pressure?

A

decrease in SNS and increase in PNS cause a decrease in arterial pressure such as in cases of shock

12
Q

Which has more impact on arterial pressure: temperature or exercise?

A

temperature
(hypothalamus to SNS to cutaneous vessels; overheated -> vasodilation and decreased MAP, hypothermic -> vasoconstriction and incrased MAP

13
Q

What controls the long term regulation of arterial pressure?

A

the fluid balance maintained by the kidneys

14
Q

Explain how urinary output can be a negative feedback loop in controlling MAP

A

increased MAP-> increased urinary output-> decreased blood volume-> decreased CO-> decreased MAP

15
Q

glomerular filtration rate subtracted from the renal fluid reabsorption rate will give you what?

A

the urinary output rate

16
Q

What enzyme is responsible for converting angiotensin to angiotensin I and where is it located?

A

Renin in the kidneys

17
Q

What is the role of ACE (angiotensin converting enzyme) in the RAAS pathway?

A

to convert inactive angiotensin I to active angiotensin II

18
Q

What does angiotensin do?

A

triggers release of aldosterone from the adrenal gland to increase sodium reabsorption in the kidneys

19
Q

When is renin released?

A

1- increased renal SNS
2- decreased glomerular filtration rate
3- SNS vasoconstriction to renal arterioles (causes 2)

20
Q

How does vasopressin (ADH) increase MAP?

A

increases water permeability in the collecting duct-> decrease urinary output -> increase blood volume-> increase CO-> increase MAP