Cardiac Physiology

Front 1

3 layers of heart

Back 1

endothelium, myocardium, endocardium

Front 2

Largest layer of heart that contracts

Back 2

myocardium

Front 3

Innermost layer of heart

Back 3

endothelium

Front 4

Pressure is greater in atria than in the ventricles, what valve opens?

Back 4

AV valves

Front 5

When the ventricle starts to contract, what happens to the AV valves and why?

Back 5

slam shut to prevent backflow into atria

Front 6

When the ventricle contracts more, what valves opens?

Back 6

semilunar valves

Front 7

The pressure in the aorta and pulmonary arteries is greater than the ventricle, what happens?

Back 7

semilunar valves slam shut

Front 8

AV valve is between what?

Back 8

Atria and ventricle

Front 9

The Chordae tendinae does/does not open and shut AV valve

Back 9

does not, it prevents backflow

Front 10

Where do you find semilunar valves

Back 10

juncture where major arteries leave ventricles

Front 11

When ventricular pressure is greater than arterial pressure, what happens

Back 11

semilunar valves open

Front 12

When do semilunar valves slam shut?

Back 12

When arterial pressure is greater than ventricular pressure

Front 13

Are there valves between the atria and veins?

Back 13

no

Front 14

2 types of cardiac muscle cells

Back 14

autorhythmic, contractile

Front 15

Do autorhythmic cells contract? What is their function?

Back 15

No, Specialized for initiating and conducting action potentials responsible for contraction of working cells

Front 16

What cells do the mechanical work of pumping?

Back 16

contractile

Front 17

Do contractile cells initiate their own action potentials?

Back 17

No

Front 18

autorhythmic action potential process

Back 18

Potassium channels close, potassium leaks out, funny sodium channels (are always open) and sodium goes in, cell depolarizes and channels open,, calcium channels open, calcium in, potassium channels open, potassium out, hits "rest"

Front 19

autorhythmic cells have ___ sodium channels, two types of ____ channels which are ___ and ____.

Back 19

funny (stay open), calcium, T-type (transient), L-type (long-lasting)

Front 20

SA node controls contractions of ___ and av node controls contractions of ____

Back 20

atria, ventricle

Front 21

Spread of Excitation

Back 21

interarterial pathway, internodal pathway, AV node transmission, ventricular excitation

Front 22

What contracts first in ventricle?

Back 22

apex

Front 23

Similarities between skeletal and cardiac muscle

Back 23

both are striated, sarcomeres, both use troponin and tropomyosin, both have T-tubules (spread quickly), sarcoplasmic reticulum, oxidative fibers

Front 24

Differences between skeletal and cardiac muscle

Back 24

intercalated disks (w/ gap junctions), desmosomes for stretching, innervated by Autonomic, influenced by hormones, calcium comes from ECF and sarcoplasmic reticulum

Front 25

Does summation or tetanus occur in cardiac muscle? Why or why not?

Back 25

No, because of the long refractory period and plateau phase

Front 26

L-Type calcium channels cause long ____ ____ in cardiac muscle

Back 26

refractory period

Front 27

What 3 ways is calcium removed from the cytosol?

Back 27

Ca ATPase in SR, Ca ATPase on plasma membrane, Na-Ca exchanger on plasma membrane

Front 28

Which is longer, diastole or systole

Back 28

diastole

Front 29

Mechanical activity consisting of alternate periods of_____ which is _____ and ______ which is _______

Back 29

systole, contraction, diastole, relaxing

Front 30

Four phases of Cardiac Cycle

Back 30

Ventricular filling, Isovolumetric ventricular contraction, Ventricular ejection, and Isovolumetric ventricular relaxation

Front 31

SV = EDV -ESV. When you increase End diastole volume, you ____ stroke volume. When you increase end systole volume, you _____ stroke volume

Back 31

increase, decrease

Front 32

First heart sound

Back 32

AV valves closing

Front 33

Second heart sound

Back 33

Semilunar valves closing

Front 34

Which sound is louder and why?

Back 34

Second heart sound because semilunar valves are under more pressure

Front 35

AV closing is at the beginning of isovolumetric ____ ____ , whereas the semilunar closing is at the beginning of the ____ ____ ____

Back 35

ventricular contraction, isovolumetric ventricular relaxation

Front 36

Formula for Cardiac output

Back 36

CO = HR X SV

Front 37

What is the main determinant of Cardiac output

Back 37

heartrate because you can change heartrate more than stroke volume

Front 38

What parts of the heart does the parasympathetic system innervate?

Back 38

SA node, AV node to slow heartrate

Front 39

What parts of the heart does the sympathetic system innervate?

Back 39

SA node, AV node to speed heartrate, ventricular myocardium

Front 40

Without parasympathetic, what would the heartrate be?

Back 40

100

Front 41

Effects of sympathetic ns on heart rate

Back 41

increased sympathetic activity, Beta adrenergic receptors on SA node, increase funny Na channels and opens Ca channels, increased rate of depolarization, increased hr

Front 42

Effects of sympathetic ns on heart rate

Back 42

increased parasympathetic activity, muscurinic cholinergic receptors in SA node, increase open state of K channels and closed state of Ca channels, decrease in spontaneous depolarization, decreased hr

Front 43

Stroke volume is influenced by 2 types of controls, ___ and ___ which are ___ and ____ respectively

Back 43

intrinsic, extrinsic, changes in end diastolic volume, sympathetic ns and hormones

Front 44

an increase of ___ ___ by increasing ____ ____

Back 44

stroke volume, contraction strength

Front 45

drop in arterial pressure will cause a/an ____ in stroke volume

Back 45

increase

Front 46

___ controls heart rate and sa node whereas ____ only controls heart rate

Back 46

sympathetic, parasympathetic

Front 47

Which part of the heart has the greatest musculature?

Back 47

Ventricle

Front 48

The opening of the AV and semilunar valves is driven by what?

Back 48

pressure differences

Front 49

The rising phase of the action potential that spontaneously occurs in the autorhythmic cells is due to

Back 49

Opening of L-type Ca channels

Front 50

What do L-type Ca channels do in the contractile cell?

Back 50

cause plateau phase

Front 51

99% of myocardial cells are

Back 51

contractile

Front 52

What is the conduction pathway through the heart?

Back 52

SA node, AV node, Bundle of His, Purkinje system

Front 53

Why can't tetanus of the heart occur?

Back 53

long refractory, prolonged plateau, ensure alternating contraction and relaxation

Front 54

During which phase of the cardiac cycle are both AV valves and semilunar valves open

Back 54

never

Front 55

what is occuring during ventricular ejections

Back 55

semilunar valves open, ventricle is contracting, blood is leaving the ventricle

Front 56

What would decrease cardiac output?

Back 56

CO = SV * HR