2nd 25

Question 1

In the action potential of a myocardial cell, the Ca2+ gates close

Answer 1

at the end of the voltage plateau.

Question 2

If the electrocardiogram exhibits a nodal rhythm

Answer 2

he heart is beating at a slow rate set by the AV node.

Question 3

The average resting cardiac cycle takes about 0.8 sec, including 0.1 sec for atrial systole, 0.3 sec for ventricular systole, and 0.4 sec for

Answer 3

the quiescent period.

Question 4

If the heart’s normal pacemaker is nonfunctional and the AV node takes over, the heart beats at a rate of 40-60 bpm called

Answer 4

Nodal Rhythm

Question 5

Blood is carried to capillaries in the myocardium by way of

Answer 5

Coronary Arteries

Question 6

Which of the following is NOT part of the conduction system of the heart?

Answer 6

The AV Valve

Question 7

The protective sac that surrounds the heart is called the

Answer 7

Pericardium

Question 8

The thick, muscular layer of the heart is the

Answer 8

Myocardium

Question 9

The majority of venous blood is received by the

Answer 9

Right Atrium

Question 10

Which heart chamber serves as the pump for the systemic circulation?

Answer 10

Left Atrium

Question 11

The heart is located in what cavity?

Answer 11

Mediastinal Cavity

Question 12

The enlarged coronary vessel outside the heart that empties blood from the myocardium into the right atrium is the

Answer 12

Coronary Sinus

Question 13

If the chordae tendineae of an animal’s heart were cut, the most likely effect would be

Answer 13

Valvular Prolapse

Question 14

Blood normally leaves the right ventricle through the

Answer 14

Pulmonary Semilunar Valve

Question 15

A heart rate of 45 bpm and an absense of P waves from the electrocardiogram would suggest what?

Answer 15

Damage to the SA node

Question 16

The fast-rising phase of the SA node action potential is due to

Answer 16

Calcium Influx

Question 17

Which of the following would result in friction?

Answer 17

a deficiency of pericardial fluid.

Question 18

Artificial pacemakers replace a function normally served by

Answer 18

SA Node

Question 19

The amount of blood (mL) coming from one ventricle in one heartbeat is called

Answer 19

Stroke Volume

Question 20

Atrial systole begins immediately after the

Answer 20

The P Wave

Question 21

The first heart sound (lub) is created by the

Answer 21

Closing of the Atrioventricular Valves

Question 22

The cardiac center, which modifies the heart rate, is located in the

Answer 22

Medulla Oblongata

Question 23

At the end of ventricular contraction, the amount of blood remaining in the ventricle is

Answer 23

End - Systolic Volume

Question 24

The heart’s normal ___ of 54% can rise to as high as 90% during strenuous exercise.

Answer 24

Ejection Fraction

Question 25

Pressure in the arteries that opposes the opening of the semilunar valves is called

Answer 25

Afterload