Cardiac Cycle

Question 1

Refractory period:

Answer 1

Occurs during an action potential.

The membrane is less responsive to another action potential.

Question 2

Skeletal muscle fiber:

Answer 2

Have a very short action potential.

2msec.

Question 3

Each action potential leads to:

Answer 3

EC Coupling.

Filament sliding.

Muscle fiber contractions.

Question 4

Each action potential causes the release of :

Answer 4

Ca++ into the sarcoplasm.

Question 5

Closely spaced action potential results in:

Answer 5

A higher Ca++ concentration in the sarcoplasm.

They prolong the contraction and increase the force of contraction.

Question 6

When an action potential reaches a certain frequency

Answer 6

A single sustained contraction is maintained.

Question 7

What are the basics for all body movements:

Answer 7

Sustained contractions.

Question 8

The prolonged action potential in cardiac cells ensures that:

Answer 8

Sustained contractions cannot occur in cardiac muscle cells.

Question 9

The contraction and action potential in a cardiac cell is completed:

Answer 9

At about the same time.

Question 10

Cardiac muscle must _____ before they can contract:

Answer 10

Relax.

Question 11

Cardiac cycle:

Answer 11

The events that occur within the heart during one heartbeat.

Question 12

What gets released during an action potential:

Answer 12

Ca++

Question 13

Systole is the term for:

Answer 13

Contraction.

Question 14

Diastole is the term for:

Answer 14

Relaxation.

Question 15

At resting heart rate, diastole:

Answer 15

Lasts longer than systole.

Question 16

Systole & Diastole:

Answer 16

Alter the blood pressure within the heart chambers and create pressure gradients that drive blood flow through the heart and vasculature.

Question 17

Pressure differences can also:

Answer 17

Open and close the heart valves.

Question 18

Semilunar valves:

Answer 18

Valves between ventricles and arteries.

Question 19

The right semi-lunar valve lies:

Answer 19

Between the right ventricle & Pulmonary trunk.

Question 20

The left semi-lunar valve lies:

Answer 20

Between the left ventricle & aorta.

Question 21

When the AV valve is open:

Answer 21

There is higher pressure in the atrium.

There is lower pressure in the ventricle.

Question 22

When the semi-lunar valve is open:

Answer 22

There is higher pressure in the ventricle.

There is lower pressure in the atries.

Question 23

When the AV valve is closed:

Answer 23

There is lower pressure in the atrium.

There is higher pressure in the ventricle.

Question 24

When the semi-lunar valve is closed:

Answer 24

There is lower pressure in the ventricle.

There is higher pressure in the atries.

Question 25

Number of phases in the cardiac cycle:

Answer 25

4.

Question 26

Phase 1 ( Ventricular filling):