Question 1

Alex goes to the hospital for a checkup after experiencing severe chest pain.After a preliminary physical examination,a health care professional asks Alex to lie down,places small metal disc electrodes on his body,and hooks the electrodes up to a machine that starts recording the electrical activity of Alex's heart.After the procedure,the health care professional hands over the recording to a doctor for analysis.This recording is known as a(n)_____.

Accepted Answer

A recording of the electrical activity of the heart results in a characteristic waveform known as the electrocardiogram (ECG). An ECG records the electrical activity of the heart from 12 different body locations or leads. Each lead position provides a different electrical view of the heart.

Question 2

Identify an accurate statement about the electrocardiogram (ECG).

Accepted Answer

A recording of the electrical activity of the heart results in a characteristic waveform known as the electrocardiogram (ECG).

Question 3

The _____ is the muscular layer of the heart.

Accepted Answer

The myocardium is the muscular layer of the heart that is responsible for cardiac muscle contraction. Contraction of cardiac muscle, the myocardium, generates the arterial blood pressure, which is necessary to distribute blood through the circulatory system.

Question 4

Identify the chamber of the heart from which deoxygenated blood is pumped through the pulmonary arteries into the lungs.

Accepted Answer

The right ventricle pumps deoxygenated blood through the pulmonary arteries to the lungs, where it gets oxygenated.

Question 5

Identify an accurate statement about the conduction system of the heart.

Accepted Answer

The Purkinje fibers of the heart distribute excitation through the ventricular myocardium.

Question 6

An increase in heart rate primarily begins with stimulation of which part of the conduction system?

Accepted Answer

Normally, an electrical impulse is generated within the sinoatrial (SA) node, referred to as the pacemaker. This impulse continues through both atria to the atrioventricular (AV) node. The AV node transmits the impulse down through the AV bundle (bundle of His) and through the left and right bundle branches and Purkinje fibers. This impulse conduction results in electrical excitation and subsequent contraction of both atria, followed by excitation and contraction of both ventricles.

Question 7

The _____ of the heart is commonly referred to as the pacemaker.

Accepted Answer

Normally, an electrical impulse is generated within the sinoatrial (SA) node, referred to as the pacemaker.

Question 8

In an electrocardiogram,the repolarization of the ventricles is represented by the:

Accepted Answer

In an electrocardiogram, the repolarization of the ventricles is represented by the T wave.

Question 9

The P wave of an electrocardiogram (ECG)represents the:

Accepted Answer

Depolarization of the atria produces the P wave of the electrocardiogram (ECG).

Question 10

What does the QRS wave of an electrocardiogram (ECG)represent?

Accepted Answer

The depolarization of the ventricles produces the QRS wave (AV node through Purkinje fibers) of the electrocardiogram.

Question 11

Deoxygenated blood passes from the right atrium into the right ventricle through the _____.

Accepted Answer

Deoxygenated blood passes through the tricuspid valve into the right ventricle. The right ventricle pumps the blood through the pulmonary arteries to the lungs, where it gets oxygenated.

Question 12

Select a true statement about the heart.

Accepted Answer

The heart is a muscular organ whose main function is to generate the force that pumps the blood through the circulatory system.

Question 13

The unique property of the heart that allows it to initiate its own electrical stimulation is known as _____.

Accepted Answer

Conduction tissue has a unique property known as autorhythmicity. This property enables the heart to initiate its own electrical stimulation.

Question 14

Which of the following statements is true of an electrocardiogram (ECG)?

Accepted Answer

Repolarization of the ventricles is represented by the T wave. The QT interval represents the time required for both depolarization and repolarization of the ventricles.

Question 15

When Janice,a patient,complains of chest pain and dizziness,Dr.Hendrick suspects that Janice is suffering from arrhythmia.Which of the following will help Dr.Hendrick confirm his suspicion?

Accepted Answer

An electrocardiogram (ECG) records the electrical activity of the heart from 12 different body locations or leads. Each lead position provides a different electrical view of the heart. This is important for detecting abnormalities and cardiac arrhythmias. The pattern of the ECG reflects depolarization and repolarization of cardiac tissue.

Question 16

The _____ carry all the deoxygenated blood from the body and drain it into the right atrium of the heart.

Accepted Answer

The superior and inferior venae cavae receive all of the venous blood from the body and drain it into the right atrium of the heart.

Question 17

Dr.Calvin is giving a lecture on the properties of cardiac tissue.During the lecture,he states that the conduction tissue of the heart does not require any external stimulus to initiate its contractions.It has the ability to initiate its own electrical stimulation.To demonstrate this property,Dr.Calvin dissects a frog and places its heart in a petri dish with Ringer's solution.He then asks his students to observe how the frog's heart continues to beat without any external stimulation.Based on the information provided in this scenario,which property of the heart is Dr.Calvin trying to demonstrate?

Accepted Answer

Dr. Calvin is trying to demonstrate the property of autorhythmicity. The conduction tissue of the heart has a unique property known as autorhythmicity. This property enables the heart to initiate its own electrical stimulation.

Question 18

Which of the following statements is true of the blood flow through the heart?

Accepted Answer

The right ventricle pumps the blood through the pulmonary arteries to the lungs, where it gets oxygenated. From the lungs the blood passes through the pulmonary veins back to the left atrium.

Question 19

Which of the following chambers of the heart pumps the blood out of the heart into the aorta,where it then gets distributed to the rest of the body?

Accepted Answer

The left ventricle pumps the blood out of the heart into the aorta, where it then gets distributed to the rest of the body.

Question 20

The excitation and contraction of the heart begins with the:

Accepted Answer

Impulse conduction through the heart results in the electrical excitation and subsequent contraction of both atria, followed by the excitation and contraction of both ventricles.

Quiz 21: Cardiac Glycosides and the Treatment of Congestive Heart Failure

Identify an accurate statement about the electrocardiogram (ECG) .