CV2

Question 1

what are the two determinants of flow

Answer 1

pressure gradient
resistance

Question 2

why does resistance oppose flow

Answer 2

friction

Question 3

______ is inversely proportional to resistance

Answer 3

flow (higher resistance, less flow)

Question 4

___________ is directly proportional to flow

Answer 4

pressure gradient (higher flow, higher pressure gradient)

Question 5

what is flow?

Answer 5

flow is the volume of fluid over a certain time. it is not how fast the liquid is flowing

Question 6

larger radius = less _________

Answer 6

resistance

Question 7

whats the primary determinant of resistance within the cardiovascular system

Answer 7

changes in radius (because of r^4)

Question 8

resistance is proportional to what (that equation)

Answer 8

resistance is directly proportional to 1/radius^4

Question 9

flow is proportional to what (that equation)

Answer 9

flow is directly proportional to 1/resistance

Question 10

what is the resistance equation

Answer 10

R= 8nl/Pi(r^4)

Question 11

a shorter length tube will have _____ resistance and _______ flow

Answer 11

less, more

Question 12

what would happen to velocity is a vessel with a small constricted area

Answer 12

it would speed up velocity

Question 13

at the same flow, would velocity be faster through a constricted vessel or a thicker vessel

Answer 13

it would be faster in a constricted vessel

Question 14

what is considered the workhouse of the body

Answer 14

the heart

Question 15

in one minute, the heart performs the equivalent work of lifting a ________ pound weight

Answer 15

5

Question 16

where does the heart lay

Answer 16

the centre of the thorax

Question 17

what is the top of the heart called

Answer 17

the base

Question 18

what is the bottom of the heart called

Answer 18

the apex

Question 19

what is the pericardium

Answer 19

a double walled sac filled with a thin layer of clear pericardial fluid

Question 20

what does pericardial fluid do?

Answer 20

lubricates the hearts external surface as it beats within the sac

Question 21

what is the heart mostly composed of

Answer 21

myocardium (cardiac muscle)

Question 22

what do atrioventricular valves do

Answer 22

allow flow from the atria into the ventricles

Question 23

what is one way flow through the heart ensured by

Answer 23

2 sets of valves
1. in heart
2. In veins

Question 24

what side of the heart is the tricuspid valve on

Answer 24

right side

Question 25

what side of the heart is the bicuspid (mitral) valve on

Answer 25

left side

Question 26

why is it called the bicuspid valve

Answer 26

there are 2 flaps

Question 27

what is the chordae tendinae

Answer 27

the tendon that attaches the AV valves to the papillary muscles on the walls of the ventricles

Question 28

do the chordae tendinaes open to valve

Answer 28

no

Question 29

what do papillary muscles do

Answer 29

they are structural muscles to supply stability to the valve

Question 30

what are semilunar valves

Answer 30

one way valves that exist between the ventricle and outflow artery

Question 31

how are semilunar valves composed

Answer 31

3 cup like leaflets

Question 32

do semilunar valves require connective tendons

Answer 32

no because their shape prevents prolapse

Question 33

what is the atrioventricular ring

Answer 33

it is the attachment point to muscle for the valves

Question 34

what does the atrioventricular ring do

Answer 34

electrically isolates the atria from the ventricles

Question 35

what is the cardia conduction system

Answer 35

a network of autorythmic cells in the heart

Question 36

where does cardiac action potential originate

Answer 36

in a group of cells in the SA node

Question 37

what else has slower pacemaker activity

Answer 37

AV node and Pukinje fibres

Question 38

what passes through the atrioventricular ring

Answer 38

bundle of His

Question 39

av bundle is also what

Answer 39

bundle of his

Question 40

whats the order of the conduction system in the heart

Answer 40

SA node internodal pathways AV node Av bundle = bundle of his bundle branches purkinje fibres

Question 41

what would take over if SA node stopped working

Answer 41

AV node

Question 42

the more HCN channels, the what

Answer 42

the faster the depolarization

Question 43

what sets the heart rate

Answer 43

the autorythmic cells with the most rapid pacemaker activity