CARDIO 4

Question 1

what are the steps in myocardial relaxation (7)

Answer 1

1. L type Ca channels closes
2. SR stops releasing Ca
3. SERCA takes up Ca into SR
4. NCX moves Ca out of cell in exchange for Na
5. Troponin stops binding Ca

Question 2

REFRACTORY PERIOD what is refractory period

Answer 2

period of time in which excitable mem cannot be re-excited

Question 3

REFRACTORY PERIOD what allows mem of myocytes to enter refractory period

Answer 3

fast Na channels inactivate

Question 4

REFRACTORY PERIOD when do fast Na channels inactivate

Answer 4

when fast Na channels close

Question 5

REFRACTORY PERIOD what is the purpose of refractory period

Answer 5

prevent tetanus

Question 6

what happens when SA node becomes damaged

Answer 6

diff parts of conducting system can act as pace maker

Question 7

when SA node becomes damaged what takes over as pace maker

Answer 7

AV node

Question 8

what does long AP in ventricles allow

Answer 8

long refractory period

Question 9

when Na current fails what takes over

Answer 9

L type Ca channels

Question 10

what does lack of fast Na channels in AV node myocytes allow

Answer 10

AV delay

Question 11

CARDIAC CYCLE what are 2 parts of cardiac cycle

Answer 11

1. systole

2. diastole

Question 12

what is systole

Answer 12

ventricular contraction

Question 13

what is diastole

Answer 13

ventricular relaxation

Question 14

what is length of cardiac cycle

Answer 14

• beginning of one heart beat

- beginning of next heart beat

Question 15

what does one hear beat involve

Answer 15

• 1 systole

- 1 diastole

Question 16

where is more time // where is less time spent

Answer 16

• more time spend in diastole

- less time spend in systole

Question 17

why is it important that more time is spend in diastole

Answer 17

ventricular filling

Question 18

SYSTOLE what are 2 phases of systole

Answer 18

1. iso volumetric contraction

2. ventricular ejection

Question 19

SYSTOLE what happens during iso volumetric contraction

Answer 19

1. pressure rises in ventricles
2. blood flows back towards atria
3. pressure gradient closes AV valve

Question 20

SYSTOLE what is happening to valves during iso volumetric contraction

Answer 20

1. AV valve closed

2. SL valve closed

Question 21

SYSTOLE what is happening to muscle during iso volumetric contraction

Answer 21

muscle generates tension but cannot shorten

Question 22

SYSTOLE what happens during ejection

Answer 22

1. pressure in ventricles becomes greater than pressure in arteries
2. ventricles eject blood into arteries

Question 23

SYSTOLE what is happening to valves during ejection

Answer 23

1. AV valve closed

2. SL valve opened

Question 24

what is stroke vol

Answer 24

vol of blood ejected from each ventricle during systole

Question 25

how does stroke vol of L and R ventricle compare

Answer 25

same - R ventricle pumps same vol of blood w less pressure - L ventricle pumps same vol of blood w more pressure

Question 26

DIASTOLE what are 2 phases of diastole

Answer 26

1. iso volumetric relaxation | 2. filling

Question 27

DIASTOLE what happens during iso volumetric relaxation

Answer 27

1. pressure decreases in ventricles 2. blood flows back towards ventricles 3. pressure gradient closes SL valve

Question 28

DIASTOLE what is happening to valves during iso volumetric relaxation

Answer 28

1. AV valve closed | 2. SL valve closed

Question 29

DIASTOLE what happens during filling

Answer 29

1. pressure in atria becomes greater than pressure in ventricles 2. blood flows from relaxed arteries to relaxed ventricles

Question 30

DIASTOLE what is happening to valves during filling

Answer 30

1. AV valves open | 2. SL valves closed

Question 31

how much ventricular filling does passive account for

Answer 31

70 percent

Question 32

how much ventricular filling does atrial contraction / atrial kick account for

Answer 32

30 percent

Question 33

what phase is atria in during atrial kick // what phase are ventricles in during atrial kick

Answer 33

- atria ==> systole | - ventricles ==> diastole

Question 34

how does pressure of atria and ventricles compare during passive ventricular filing

Answer 34

- atria, high pressure | - ventricles, low pressure

Question 35

why do atria have higher pressure than ventricles

Answer 35

atria full of blood

Question 36

when is pressure generated (2)

Answer 36

1. chamber contracts | 2. chamber fills (w blood)

Question 37

what direction does blood flow

Answer 37

from region of higher pressure to region of lower pressure

Question 38

what causes valves to open and close

Answer 38

pressure gradient - forward pressure gradient opens valve - backward pressure gradient closes valve

Question 39

what is end diastolic volume

Answer 39

vol of blood in each ventricle at end of diastole

Question 40

what is end systolic volume

Answer 40

vol of blood in each ventricle at end of systole

Question 41

how to calculate stroke volume

Answer 41

end diastolic volume - end systolic vol

Question 42

what happens to atria during diastole

Answer 42

receive blood from veins

Question 43

how does ventricular ejection occur

Answer 43

fast to slow

Question 44

what happens to aortic pressure during ventricular ejection

Answer 44

high to low

Question 45

what is 1st heart sound

Answer 45

lub

Question 46

what causes lub

Answer 46

closure of AV valve

Question 47

when do AV valves close to cause lub sound

Answer 47

beginning of systole

Question 48

what is 2nd heart sound

Answer 48

dub

Question 49

what causes dub

Answer 49

closure of SL valve

Question 50

when do SL valves close to cause dub sound

Answer 50

beginning of diastole

Question 51

what is compliance

Answer 51

ability to expand and increase vol with increasing pressure

Question 52

what is compliance formula

Answer 52

change in vol / change in pressure

Question 53

what is compliance of rigid tube

Answer 53

no compliance

Question 54

what does no compliance mean

Answer 54

increase in pressure = infinity increase in vol = 0

Question 55

what is compliance of no resistance tube

Answer 55

infinite compliance

Question 56

what does infinite compliance mean

Answer 56

increase in pressure = 0 increase in vol = infinity

Question 57

what kind of compliance do walls of blood vessels have

Answer 57

finite

Question 58

what does finite compliance mean

Answer 58

- increase in vol | - increase in pressure

Question 59

what determines bp

Answer 59

1. vol of blood in vessels | 2. compliance of vessels

Question 60

what happens to walls of arteries during systole

Answer 60

increase diameter . increase vol (aorta walls expand)

Question 61

what happens to walls of arteries during diastole

Answer 61

decrease diameter / decrease vol (aorta walls recoil)

Question 62

why do arteries have compliance

Answer 62

able to increase vol + expand w increased pressure

Question 63

what happens to some of the blood that ventricles pump into arteries during systole

Answer 63

remains in arteries

Question 64

what happens to blood that remains in arteries during diastole

Answer 64

moves into arterioles