Chapter 9 & 10 - Cardiac Physiology

Question 0

Dark areas crossing the cardiac muscles. They are actually cell membranes that separate individual cardiac muscles cells from one another.

Answer 0

Intercalated discs

Question 1

3 major types of cardiac muscles in the heart

Answer 1

1. Atrial muscle
2. Ventricular muscle
3. Specialized excitatory & conductive muscle fibers

Question 2

The heart is composed of 2 syncitiums. What are those?

Answer 2

1. Atrial syncitium

2. Ventricular syncitium

Question 3

2 types of channels that cause an action potential in cardiac muscles

Answer 3

1. The same fast sodium channels as those in skeletal muscles
2. Slow calcium channels aka calcium sodium channels

Question 4

It is the interval of time during which a normal cardiac impulse cannot reexcite an already excited area of cardiac muscle

Answer 4

Refractory period of the heart

Question 5

The mechanism by which the action potential causes the myofibrils of the muscles to contract

Answer 5

Excitation-contraction coupling

Question 6

The cardiac events that occur from the beginning of one heartbeat to the beginning of the next

Answer 6

Cardiac cycle

Question 7

A period of relaxation in the cardiac cycle during which the heart fills with blood

Answer 7

Diastole

Question 8

A period of contraction in the cardiac cycle

Answer 8

Systole

Question 9

Atrioventricular valves

Answer 9

Tricuspid valve

Mitral valve

Question 10

Semilunar valves

Answer 10

Aortic valve

Pulmonary artery valve

Question 11

They do not help the valves close but instead they pull the vanes of of the valves inward toward the ventricles to prevent their bulging too far back toward the atria during ventricular contraction

Answer 11

Papillary muscles

Question 12

The ____ valves are supported by the chordae tendinae

Answer 12

AV valves

Question 13

Amount of energy that the heart converts to work during each heartbeat while pumping blood into the arteries

Answer 13

Stroke work output

Question 14

The total amount of energy converted to work in 1 minute, hpthis is equal to the stroke workoutput times heart rate per minute

Answer 14

Minute work output

Question 15

Load against which the muscle exerts its contractile force

Answer 15

Afterload

Question 16

Degree of tension on the muscle when it begins to contract

Answer 16

Preload

Question 17

End diastolic pressure when the ventricle has become filled

Answer 17

Preload

Question 18

Pressure in the aorta leading from the ventricle

Answer 18

Afterload

Question 19

Basic means by which the volume pumped by the heart is regulated

Answer 19

1. Intrinsic cardiac regulation of pumping in response to changes in volume of blood flowing into the heart
2. Control of heart rate & strength if pumping by ANS

Question 20

The intrinsic ability of the heart to adapt to increasing volumes of inflowing blood

Answer 20

Frank-starling mechanism of the heart

Otto Frank & Ernest Starling

Question 21

The greater the heart muscle is stretched durimg filling, the greater is the force of contraction and the greater the quantity of pumped blood into the aorta

Answer 21

Frank-Starling mechanism

Question 22

Within physiologic limits, the heart pumps all the blood that returns to it by the way of the veins

Answer 22

Frank-Starling mechanism

Question 23

Amount of blood pumped each minute

Answer 23

Cardiac output

Question 24

A process that can cause automatic rhythmical discharge & contraction

Answer 24

Self-excitation

Question 25

Pacemaker of the heart

Answer 25

SA node / sinoatrial node

Question 26

A pacemaker elsewhere than sinus node. It causes an abnormal sequence of contraction of different parts of the heart and can cause significant debility of heart pumping

Answer 26

Ectopic pacemaker