Chapter 13 (Part 3)

Question 1

what is the opposite of arterial contraction?

Answer 1

vein smooth muscles contract to increase blood flow rate back to the heart.

Question 2

why is venous contraction like putting my thumb over a garden hose?

Answer 2

if veins constrict, the same amout of blood delivered by the arteries needs to move faster through the smaller venous diameter

Question 3

veins serve as a… what?

Answer 3

blood reservoir

Question 4

which has higher compliance: veins or arteries?

Answer 4

veins

Question 5

what does higher compliance mean?

Answer 5

can be expanded easier to hold more blood

Question 6

why do veins have higher compliance than arteries? (2)

Answer 6

• more blood is held in veins than arteries
• veins are more elastic due to thinner walls

Question 7

name two causes of lower stroke volume / pulse pressure / pulse value

Answer 7

1. trauma
2. congestive heart failure

Question 8

why does trauma result in lower pulse value?

Answer 8

blood loss = lower BP = lower pulse value

Question 9

what causes congestive heart failure?

Answer 9

fluid around the heart limits pumping

Question 10

what two things influence MAP? and what does MAP even stand for?

Answer 10

Mean Arterial Pressure:
1. CO
2. TPR

Question 11

what is CO?

Answer 11

cardiac output; how hard your heart is working

Question 12

what is TPR?

Answer 12

total peripheral resistance;

Question 13

combination of constriction in one place and dilation in another can result in what?

Answer 13

no change, or even a decrease in TPR

Question 14

carotid and aortic baroreceptors are…. what kind of receptors?

Answer 14

tonic sensory receptors

Question 15

name two kinds of tonic sensory receptors

Answer 15

carotid and aortic baroreceptors

Question 16

where are baroreceptor APs sent, and where is that located?

Answer 16

cardiovascular control center in the medulla oblongata of the brain stem

Question 17

what is the primary way to change TPR?

Answer 17

depends on radius of peripheral arterioles

vasodilation = decreased TPR
vasoconstriction = increased TPR

Question 18

what is orthostatic hypotension? how does it lead to lower blood volume?

Answer 18

• when lying flat, blood gets evenly distributed throughout your body
• standing causes blood to pool in lower extremities
• bedrest or zero gravity = blood is evenly distributed all the time = no more blood pooling = greater venous return all the time
• body responds by triggering the kidneys to excrete what is perceived as excess fluid to lower blood volume

Question 19

why doesn’t MAP increase a lot during light exercise?

Answer 19

because total peripheral resistance decreases

Question 20

why can a stressed-out life lead to hypertension?

Answer 20

increased CO without a physical need to do so

vasodilation does not occur in muscles

end result is increased TPR

over time, this can lead to high BP

baroreceptors reset to higher baseline BP and treat it as normal rather than respond to try and lower BP

Question 21

what is the cause of renal failure?

Answer 21

kidney glomeruli ruptured by high BP

Question 22

why would kidney glomeruli rupture by high BP?

Answer 22

long term hypertension