Lecture 3

Question 1

Cardiac output

Answer 1

Volume of blood pumped out by each ventricle
per minute

Question 2

Question 3

Regulating blood pressure
Short term (seconds)

Answer 3

Cardiac output & total peripheral resistance → autonomic nervous system

Question 4

Regulating blood pressure
Long term (minutes to days)

Answer 4

Adjusting the volume of blood → restoring salt & water balance → impact on urine output and thirst

Question 5

Short term responses are stimulated by

Answer 5

Baroreceptors

Carotid sinus
Aortic arch

Respond to mean
and pulse pressure

Question 6

Question 7

Question 8

Arterioles have major resistance, why?

Answer 8

Small radius

Question 9

Arterioles regulate resistance, how?

Answer 9

Smooth muscle cells run circulatory around the vessel- constrict = higher pressure = higher resistance

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Venus return

Answer 16

Volume of blood entering each atrium per minute

Question 17

Veins stretch but don’t

Answer 17

recoil like arteries

Question 18

Veins act as a

Answer 18

Blood reservoir (at rest contain more than 60% of blood)

Question 19

Smooth muscle of veins

Answer 19

Vasoconstriction

– Increases resistance but large radius of veins means
extra resistance has little effect

– Moderately increases venous pressure

Question 20

Vein valves

Answer 20

Constricting veins – one way blood flow

Question 21

Question 22

Question 23

What happens if a person stands still for a very long time with no movement?
Valves help keep the person upright
Vasoconstriction keeps the person upright
The person doesn’t stay upright
Two of these option

Question 24

Gravity on venous pressure

Question 25

Question 26

Question 27

Question 28

Question 29

Question 30

AV valves open and close together

Semilunar valves open and close together

Question 31

What happens to the valves when the papillary muscle contracts?

Answer 31

The papillary muscles are “nipple” like projections of the myocardia and contract when the myocardia contracts. As a result, they pull on the chordae tendinae and help to prevent prolapsing of the AV valves.

Question 32