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Flashcards in systemic circulation Deck (34):
1

in blood vessels, as volume increases what does pressure do?

increase

2

what is the compliance equation?

C= change in volume/change in transmural pressure

3

what is the elastance equation?

E= 1/C
= change in transmural pressure/change in volume

4

describe the structure of an artery

very round, thick wall, a lot of collagen, a lot of extracellular material

5

describe the structure of a vein

“floppy”, thin walled

6

can compliance be homeostatically regulated?

NO

7

about what is the compliance for the aorta?

~2mL/mmHg

8

about what is the compliance for veins?

100 mL/mmHg

9

arteries or veins, what does this statement describe
"small pressure changes have large volume changes"

describing the high compliance of veins

10

how much more volume do veins have than arteries?

about 3x

11

how much more distensible are veins than arteries?

8x

12

when will blood pressure drop to zero?

if blood volume dorps below 400 mL

13

veins or arteries; which has lower pressure?

veins

14

veins or arteries; which has higher blood volume?

veins

15

what happens to compliance as a person ages?

it decreases

16

what is 1 consequence of reduced compliance?

the heart must work harder to pump blood through stiffer vessels

17

describe the windkessel effect

the aorta, pulmonary artery and their major branches store a volume of blood (and elastic energy) during systole and then deliver the blood to the periphery during diastole to maintain blood flow in the body

18

in systemic circulation what is one word that describes pressure on the arterial side?

pulsatile

19

where is the greatest pulse pressure?

left ventricle

20

what happens to pressure with increasing distance from the heart?

it decreases

21

what happens to pulse pressure with age?

increases

22

what happens to stroke volume with age?

goes up

23

why does the dicrotic notch (incisura) occur?

there is a reversal of pressure (ventricle pressure is lower than aortic pressure) causing a momentary reversal of blood flow which closes aortic valves and creases a transient increase in aortic pressure

24

the reversal of flow seen directly before the aortic valve closure is important for what?

perfusion of the coronary arteries

25

what is the equation for tension?

T= transmural pressure x radius

26

define tension

a force exerting its effect along the wall circumference and is often described as “the force that would pull apart a LONGITUDINAL slit in the wall”

27

how do blood vessels respond to pressure changes?

by expanding or contracting their vessel
or by increasing the opposing force by smooth muscle contraction

28

what is a possible consequence of increased tension

aneurism

29

without any sympathetic stimulation, at what pressure will flow completely stop?

~ 6mmHg

30

vasoconstriction in response to hemorrhage can do what?

mobilize blood from the venous reseve

31

a sympathetic response to hemorrhaging would do what to a compliance curve?

shift it to the left so that BP can be maintained at a lower volume

32

what is raynaud's disorder?

Brief episodes of vasospasm (narrowing of the blood vessel diameter)

33

in raynaud's disorder what commonly triggers the vasospasms?

cold temperature or emotional stress

34

what is the typical sequence of a reynaud's attack

digits first turn white (ischemia), blue (deoxygenation) then red (reprofusion). After it subsides, blood flow can return but can be with discomfort