Deck 46: Cardiac Cycle

Question 1

The AV node controls the basic rhythm of the heart, so it is called the pacemaker, but the SA node can modify heart rate when necessary.

Answer 1

False

Question 2

Which of the following structures of the cardiac conduction system transmits electrical signals directly to the Purkinje fibers?

A)AV node
B)Internodal fibers
C)Right and left bundle branches
D)AV bundle
E)SA node

Answer 2

C

Question 3

During the cardiac cycle, the semilunar valves close during ventricular diastole.

Answer 3

True

Question 4

During the cardiac cycle, ventricular depolarization and repolarization both begin at the apex of the heart and progress superiorly.

Question 5

The AV bundle and the bundle branches are located in the ________ of the heart.

A)right atrium
B)interventricular septum
C)aorta
D)left atrium
E)interatrial septum

Question 6

Sounds associated with the mitral valve can best be heard by listening with a stethoscope in the

A)second intercostal space, to the right of the sternum.
B)fifth intercostal space, just to the right of the sternum.
C)directly over the middle of the sternum.
D)second intercostal space, to the left of the sternum.
E)fifth intercostal space, to the left of the sternum, along the nipple line.

Question 7

The lead arrangement known as Einthoven's triangle, which is used to record an ECG, involves placing recording electrodes on

A)both wrists and the left ankle.
B)both ankles and the right wrist.
C)both ankles and the left wrist.
D)the left and right shoulders and the navel.
E)both wrists and the right ankle.

Question 8

The time required for the ventricles to contract is represented by the ________ of the ECG.

A)P-Q segment
B)QRS complex
C)T wave
D)P wave
E)S-T segment

Question 9

Which of the following events is not observed in the ECG, because it is hidden in the QRS complex?

A)Atrial depolarization
B)Ventricular repolarization
C)Atrial systole
D)Atrial repolarization
E)Ventricular depolarization

Question 10

In the cardiac cycle, the atria relax while the ventricles are contracting.

Question 11

In the ECG pattern, how do segments differ from intervals?

A)Intervals do not include waves or intervals, while segments do.
B)Segments are much longer in duration than intervals.
C)Segments involve important cardiac cycle events, while intervals have no significance.
D)Segments do not include waves or complexes, while intervals do.
E)Intervals involve important cardiac cycle events, while segments have no significance.

Question 12

Which of the following shows the components of the cardiac conduction system in the correct sequence?

A)AV bundle, left and right bundle branches, SA node, AV node, Purkinje fibers
B)AV node, SA node, Purkinje fibers, AV bundle, left and right bundle branches
C)SA node, AV node, AV bundle, left and right bundle branches, Purkinje fibers
D)Purkinje fibers, left and right bundle branches, AV bundle, SA node, AV node
E)SA node, Purkinje fibers, AV node, AV bundle, left and right bundle branches

Question 13

The first and second heart sounds are derived from the opening of the heart valves.

Question 14

In the ECG pattern, the P wave is soon followed by the P-Q segment, which represents

A)atrial systole.
B)ventricular diastole.
C)atrial repolarization.
D)atrial diastole.
E)ventricular systole.

Question 15

In the standard leads I, II, and III used in this lab exercise, which location is used as the ground?

A)The left ankle
B)The right wrist
C)The right ankle
D)The left wrist
E)Either wrist or either ankle can be used as the ground.