Dani - ch 9

Question 1

cardiac and skeletal muscle both fibers have a ___ appearance

Answer 1

striated

Question 2

cardiac and skeletal muscle both rely on the opening of ___ ___ channels to initiate the action potential for contraction

Answer 2

fast sodium

Question 3

cardiac and skeletal muscle contraction both are based on ____ filaments

Answer 3

sliding

Question 4

cardiac muscle is most similar to ___ __ fibers

Answer 4

type I

Question 5

Type I fibers are ___ twitch fibers, have more ___, and have ____ conducting neurons

Answer 5

slow
mitochondria
slow

Question 6

cardiac muscle is ___ while skeletal is ____

Answer 6

involuntary

voluntary

Question 7

cardiac fibers are interconnected by ___ disks

Answer 7

intercalated

Question 8

the heart is divided into two functional ____ which allows the atria to contract before the ventricles

Answer 8

synctia

Question 9

cardiac muscle has ___ ___ channels that must open to achieve action potentials

Answer 9

slow calcium

Question 10

slow calcium channels of cardiac muscles cause a ____ in the action potential

Answer 10

plateau

Question 11

duration of cardiac contraction is ~___ times longer for cardiac muscle than skeletal muscle

Answer 11

10

Question 12

intercalated disks serve to fuse the cells together to form ___ ___ allowing for rapid diffusion of ions

Answer 12

gap junctions

Question 13

gap junctions allow the action potential to travel rapidly from one cardiac ___ to the next

Answer 13

myoctye

Question 14

at rest, the intracellular surface is ~___mV and if threshold is reached, it continues to ____mV at the peak of the AP

Answer 14

-85

20

Question 15

for cardiac muscle, once the AP spikes at about ____mV, it begins to repolarize but ____ before it completely repolarizes

Answer 15

20

plateaus

Question 16

the plateau is the reason why cardiac contraction is significantly ____ than skeletal

Answer 16

longer

Question 17

phase 0 of AP

- opening of ___ ____ channels –> rapid _____

Answer 17

fast sodium

depolarization

Question 18

phase 1 of AP

- at peak, repolarization begins = short ____ interval betweek peak and beginning of plateau

Answer 18

downward

Question 19

phase 2 of AP

- opening of ___ ___ channels and continues sodium influx = ____

Answer 19

slow calcium

plateau

Question 20

phase 2 of AP

- when slow calcium channels open, decrease outflux of sodium –> ____

Answer 20

plateau

Question 21

phase 3 of AP

- ___ ____ channels close so increase of potassium outflow –> rapid ____

Answer 21

slow calcium

repolarization

Question 22

___ ____ ___: the interval during the AP when a “normal” electrical impulse cannot re-excite the already excited area

Answer 22

absolute refractory period

Question 23

___ ___ ___: a stronger than normal stimulus can re-excite the area

Answer 23

relative refractory period

Question 24

there is no ___ ___ in cardiac muscle from premature contractions

Answer 24

wave summation

Question 25

unlike skeletal myofibrils, cardiac myocytes rely on ___ ____ for contraction to occur

Answer 25

extracellular calcium

Question 26

extracellular calcium enter the cardiac __ ____ and then enter the ___ via voltage gated calcium channels

Answer 26

t-tubules | sarcoplam

Question 27

the influx of calcium activates the ____ recpetors on the SR membrane which triggers the SR to release ____

Answer 27

ryanodine | calcium

Question 28

at the end of contraction, calcium is pumped back into the SR via the ___-____ pump

Answer 28

calcium-ATPase

Question 29

calcium exits the sarcoplasm via the ___-___ exchanger

Answer 29

sodium-calcium

Question 30

the sodium entering through the sodium-calcium pump is transported back out of the cell via ____-___ exchange pump

Answer 30

sodium-potassium

Question 31

sodium-potassium pump - __ sodium out - __ potassium in

Answer 31

3 | 2

Question 32

duration of atrial contraction

Answer 32

.2 sec

Question 33

duration of ventricular contraction

Answer 33

.3sec

Question 34

____ ____: series of events that occur from the onset of one heart beat to the beginning of the next heart beat

Answer 34

cardiac cycle

Question 35

cardiac cycle is often defined as __ wave to __ wave

Answer 35

P | P

Question 36

calculate total duration of a single cardiac cycle as a ___ of ___ ____

Answer 36

reciprocal | heart rate

Question 37

RHR = __/___

Answer 37

1/HR

Question 38

duration of systole at rest is about __% of total duration

Answer 38

40

Question 39

when HR increases, the total duration of cardiac cycle decreases but the relative time spent in ventricular systole actually ___

Answer 39

increases

Question 40

duration of systole at elevated HR is about __% of total duration

Answer 40

65

Question 41

1st heart sound is marked by the ___ valves closing

Answer 41

AV

Question 42

isovolumic contraction after the ___ valve close and before the ___ valve opens

Answer 42

AV | aortic

Question 43

isovolumic relaxation is after the ___ valves close and before ___ valve opens

Answer 43

aortic | AV

Question 44

you have to have ventricular contraction for the ___ valve to open

Answer 44

aortic

Question 45

QRS complex happens during the ___ heart sound

Answer 45

1st

Question 46

as ventricle contrace, the AV valves close = ___ heart sound

Answer 46

first

Question 47

first heart sound is ___ pitched and ___ lasting

Answer 47

low | long

Question 48

at the end of ventricular systole, the aortic and pulmonary valves snap shut = __ heart sound

Answer 48

2nd

Question 49

2nd heart sound is ____

Answer 49

short

Question 50

at the end of rapid filling. the AV valves opened and blood rushes from the atrium to the ventricles, the ventricle walls expand and is though it is the sound of blood against the ventricle walls = ___ heart sound

Answer 50

3rd

Question 51

3rd heart sound = often ___ heard

Answer 51

isnt

Question 52

p wave = depolarization of the ___

Answer 52

atria

Question 53

p wave = atrial contraction follows which causes a slight ___ on the atrial pressure curve

Answer 53

increase

Question 54

QRS complex = depolarization of the ___

Answer 54

ventricles

Question 55

QRS complex = ventricular contraction follows causing the significant ____ on the ventricular pressure curve

Answer 55

increase

Question 56

T wave = repolarization of the ____ occurs before ventricular contraction is complete

Answer 56

ventricles

Question 57

T wave = followed by relaxation of ventricles with a significant ____ on the ventricular pressure curve

Answer 57

decrease

Question 58

isovolumetric contraction = when ventricular ___ begins; ventricular pressure must rapidly ___ to build up pressure to push open the ___ valves against arterial pressure

Answer 58

contraction increase semilunar

Question 59

isovolumetric contraction = tension has ___ without a shortening of the cardiac fibers

Answer 59

increased

Question 60

2 periods of ejection

Answer 60

rapid | slow

Question 61

rapid ejection = ventricular pressure reaches __mmHg which pushes open the semilunar valves

Answer 61

80

Question 62

rapid ejection = about __% of the blood volume that is ejected during a single contraction pours out of the ventricles during the first __/__ of the ejection period

Answer 62

70 | 1/3

Question 63

slow ejection = the remaining __% of the blood volume ejected takes the remaining __/__ of the ejection period

Answer 63

30 | 2/3

Question 64

isovolumetric relaxation = at the end of ventricular ___, intraventricular pressure ___ rapidly and the pressure in the great arteries ___ which pushes blood back toward the ventricles and the semilunar valves ___ ___

Answer 64

contraction decreases increase snap shut

Question 65

isovolumetric relaxation = ventricular volume ___ changed, the ventricles _____. intraventricular pressures continue to ____ rapidly and the ___ valves open to begin filling ventricles again

Answer 65

hasn't relax decrease AV

Question 66

first 1/3 of filling of the ventricles is called ____ filling

Answer 66

rapid

Question 67

during systole, AV valves are closed so when systole ends and the pressure in the ventricles ___ and the blood accumulated in the atria ___ atrial pressure and pushes the ___ valves open so blood rapidly flows into the ventricles

Answer 67

decrease increase AV

Question 68

second 1/3 of ventricular filling = blood returning to the heart continues to pass ____ through the atria into the ventricles

Answer 68

directly

Question 69

last 1/3 of ventricular filling = ___ contract giving last push of blood into the ventricles. accounts for about __% of total filling

Answer 69

atria | 20

Question 70

a wave of atrial pressure changes = caused by ___ contraction so occurs after the ___ wave on the ECG

Answer 70

atrial | P

Question 71

c wave of atrial pressure changes = caused by beginning of ___ contraction

Answer 71

ventricular

Question 72

c wave of atrial pressure changes = rapid ___ in ventricular pressure causes the closed ___ valves to bulge back toward the atria

Answer 72

increase | AV

Question 73

v wave of atrial pressure changes = occurs at the end of ___ contraction while the ___ valves are still closed as more blood is returning to the atria from the great veins

Answer 73

ventricular | AV

Question 74

blood returning to the heart from the great veins first goes to the atria but __% passes right through the open ___ valves into the ventricles

Answer 74

80 | AV

Question 75

the atria are called ___ pumps because the ___ of these upper chambers only provides the last __% to fill the ventricles

Answer 75

primer contraction 20

Question 76

if the atria fail to contract properly, there __ enough blood in the ventricles to pump to the peripheral organs to meet the demands under resting conditions

Answer 76

is

Question 77

aorta and systemic arteries work at a __ pressure compared to the pulmonary arteries

Answer 77

higher

Question 78

pressure in the ventricles has to be more than the ___ pressure

Answer 78

aortic

Question 79

after the peak of the ejection period, aortic pressure begins to ___ similar to the __ in ventricular pressure

Answer 79

decrease | decrease

Question 80

when aortic valve closes there is a slight __ in pressure called the ___

Answer 80

incisure

Question 81

incisura is caused by the cessation of ___ of blood when the valve snaps shut

Answer 81

backflow

Question 82

___ ____ ___ = at the end of ventricular diastole, the volume of blood in each ventricle ~120mmHg

Answer 82

end diastolic volume

Question 83

___ ___ ___ = the volume of blood remaining in the ventricles after contraction is ~50mmHg

Answer 83

end systolic volume

Question 84

___ ___ = the volume of blood ejected from the ventricles during systole is ~70mmHg

Answer 84

stroke volume

Question 85

___ ___ = the fraction of the EDV that is ejected during systole

Answer 85

ejection fraction

Question 86

ways to increase SV during exercise= - ___ EDV w/ ___ heart - ___ ESV

Answer 86

increase stronger ESV

Question 87

___ and ___: terms used to assess the contractile properties of a muscle fiber

Answer 87

preload | afterload

Question 88

___ = tension on the muscle fibers at the onset of contraction

Answer 88

preload

Question 89

preload is the ___ pressure resulting resulting from EDV

Answer 89

diastolic

Question 90

___ = the pressure in the LV to overcome the pressure in the aorta the ventricle can eject blood into the aorta

Answer 90

afterload

Question 91

cardiac muscle has a high number of ___

Answer 91

mitochondria

Question 92

heart metabolizeds ___ ___, __ and __

Answer 92

FA glucose lactate

Question 93

___ ___: the additional work required for a contraction to move toward completely emptying the LV

Answer 93

potential work

Question 94

__-__% of chemical energy is converted into work energy and ___-__% to heat

Answer 94

20-25 | 75-80

Question 95

avg person pumps __-__ liters of blood out of the heart per minute which is CO

Answer 95

4-6

Question 96

__ ___: amount of blood flowing into the RA from the great veins

Answer 96

venous return

Question 97

sympathetic stimulation increases ___ __ and __ __

Answer 97

heart rate | stroke volume

Question 98

PS stimulation: serves to ___ the heart rate

Answer 98

slow

Question 99

vagal stimulation primarily effects the ___

Answer 99

atria