Question 1

The _____ period follows depolarization of the myocardium and represents a period during which no new cardiac potential can be propagated.
A) absolute refractory
B) hyperpolarization
C) resting
D) threshold

Accepted Answer

During the absolute refractory period, the myocardium is completely depolarized and unable to respond to any new stimuli, thus preventing the propagation of new cardiac potential.

Question 2

A 52-year-old female is admitted to the cardiac unit with a diagnosis of pericarditis. She asks the nurse to explain where the infection is. In providing an accurate description, the nurse states that the pericardium is:
A) the outer muscular layer of the heart.
B) the innermost lining of the heart chambers.
C) a membranous sac that encloses the heart.
D) the heart's fibrous skeleton.

Accepted Answer

The pericardium is a membranous sac that encloses the heart. Pericarditis is an inflammation of this sac, which can be caused by an infection or other underlying condition.

Question 3

Depolarization of a cardiac muscle cell occurs as the result of:
A) a decrease in the permeability of the cell membrane to ions.
B) the rapid movement of ions across the cell membrane.
C) a blockade by calcium ions.
D) stimuli instigated during the refractory period.

Accepted Answer

Depolarization of a cardiac muscle cell occurs due to the rapid movement of ions across the cell membrane, specifically the movement of sodium (Na+) ions into the cell. This influx of positive ions causes the cell membrane potential to become more positive, leading to depolarization.

Question 4

Oxygenated blood flows through the:
A) superior vena cava.
B) pulmonary veins.
C) pulmonary artery.
D) cardiac veins.

Accepted Answer

The pulmonary veins are the only vessels that carry oxygenated blood from the lungs to the heart.

Question 5

The chamber that receives blood from the systemic circulation is the:
A) right atrium.
B) right ventricle.
C) left atrium.
D) left ventricle.

Accepted Answer

The right atrium receives blood from the systemic circulation.

Question 6

In a normal electrocardiogram, the P-R interval represents:
A) atrial depolarization.
B) ventricular depolarization.
C) onset of atrial activation to onset of ventricular activity.
D) "electrical systole" of the ventricles.

Accepted Answer

The P-R interval on an electrocardiogram represents the time from the onset of atrial activation to the onset of ventricular activity. This is measured from the beginning of the P-wave to the beginning of the QRS complex. Atrial depolarization is represented by the P-wave alone, and ventricular depolarization is represented by the QRS complex alone. The P-R interval reflects the delay between the activation of the atria and the activation of the ventricles, allowing time for the atria to contract and fill the ventricles before they contract.

Question 7

The _____ represents the sum of all ventricular muscle cell depolarization.
A) PR interval
B) QRS complex
C) QT interval
D) P wave

Accepted Answer

The QRS complex represents the depolarization of the ventricular muscle cells, which sum up to produce a large electrical signal that is recorded on an electrocardiogram (ECG). The PR interval represents the time it takes for the electrical signal to travel from the atria to the ventricles, the QT interval represents the duration of ventricular depolarization and repolarization, and the P wave represents the atrial depolarization.

Question 8

A 65-year-old male develops blockage in the pulmonary artery. As a result, blood would first back up into the:
A) aorta.
B) left ventricle.
C) pulmonary veins.
D) right ventricle.

Accepted Answer

The pulmonary artery carries blood from the right ventricle to the lungs, so if there is a blockage in the pulmonary artery, blood would back up into the right ventricle.

Question 9

A 50-year-old female received trauma to the chest that caused severe impairment of the primary pacemaker cells of the heart. Which of the following areas received the greatest damage?
A) AV node
B) SA node
C) Bundle of His
D) Ventricles

Accepted Answer

The SA node (sinoatrial node) is the primary pacemaker of the heart and initiates the heartbeat. Damage to this area would cause the most severe impairment of the primary pacemaker cells. The AV node (atrioventricular node) and Bundle of His can also generate impulses, but not as rapidly as the SA node. Damage to the ventricles would affect the contraction of the heart muscle, but not necessarily the generation of impulses.

Question 10

The _____ artery travels down the interventricular septum and delivers blood to portions of the left and right ventricle.
A) right coronary
B) circumflex
C) left anterior descending
D) cardiac

Accepted Answer

The left anterior descending artery (also known as the anterior interventricular artery) travels down the interventricular septum and delivers blood to portions of the left and right ventricle.

Question 11

A function of the pericardium is to:
A) provide a barrier against extracardial infections.
B) improve blood flow through the heart.
C) play a role in cardiac conduction.
D) assist in cardiac contraction.

Accepted Answer

The pericardium serves as a protective sac that surrounds and isolates the heart from other organs, tissues, and infections in the body.

Question 12

A 54-year-old male is diagnosed with left bundle branch block. Which of the following structures would not receive an electrical impulse?
A) AV node
B) SA node
C) Bundle of His
D) The left ventricles

Accepted Answer

The left bundle branch block (LBBB) affects the electrical conduction to the left ventricle, preventing it from receiving the impulse directly through the normal conduction pathway.

Question 13

A 20-year-old male underwent an echocardiogram to assess chest pain. Results revealed a congenital defect in papillary muscles. Which of the following would occur?
A) Semilunar valve closure
B) Backward expulsion of the atrioventricular valves
C) Atrioventricular valve closure
D) Backward expulsion of the semilunar valves

Accepted Answer

Papillary muscles are responsible for holding the atrioventricular valves in place during ventricular contraction. If there is a congenital defect in the papillary muscles, they may not be able to maintain the valve closure during systole (ventricular contraction), leading to regurgitation (backflow) of blood into the atria. Therefore, backward expulsion of the atrioventricular valves is the most likely outcome in this case.

Question 14

A 13-year-old female took a weight loss drug that activated the sympathetic nervous system. Which of the following would be expected?
A) Decreased myocardial contraction
B) Decreased heart rate
C) Increased cardiac cycle speed
D) Increased intranodal conduction time

Accepted Answer

Activation of the sympathetic nervous system causes an increase in heart rate and cardiac output, leading to an increase in cardiac cycle speed. A decrease in myocardial contraction or heart rate would not be expected with sympathetic activation. Intranodal conduction time may decrease with sympathetic activation, not increase.

Question 15

Venous blood from the coronary circulation drains into the:
A) superior vena cava.
B) inferior vena cava.
C) right atrium.
D) left atrium.

Accepted Answer

Venous blood from the coronary circulation drains into the right atrium via the coronary sinus.

Question 16

The coronary ostia (the openings to the coronary arteries) are found in the:
A) left ventricle.
B) inferior vena cava.
C) coronary sinus.
D) aorta.

Accepted Answer

The coronary ostia are the openings to the coronary arteries and they are located in the aorta, which is responsible for supplying oxygenated blood to the body.

Question 17

A 65-year-old male is transported to the ER for chest pain. An electrocardiogram reveals a prolonged QRS interval. This result indicates:
A) increased ejection time.
B) increased isovolumetric contraction time.
C) mitral valve opening.
D) aortic valve closing.

Accepted Answer

A prolonged QRS interval on an electrocardiogram indicates an increased isovolumetric contraction time, which may be indicative of a conduction abnormality within the heart's electrical system. This can lead to impaired ventricular function and decreased cardiac output.

Question 18

_____ are the anchors of the atrioventricular valves.
A) Chordae tendineae cordis
B) Great vessels
C) Coronary ostia
D) Trabeculae carneae

Accepted Answer

Chordae tendineae cordis are thin, strong, fibrous strings that connect the AV valves (mitral/tricuspid) to the papillary muscles in the ventricles, preventing them from flipping inside out during ventricular contraction.

Question 19

The chamber of the heart that generates the highest pressure is the:
A) right atrium.
B) left atrium.
C) left ventricle.
D) right ventricle.

Accepted Answer

The left ventricle generates the highest pressure in order to pump oxygen-rich blood out to the rest of the body through the aorta. This is because the left ventricle has thicker muscular walls than the right ventricle to generate higher pressure. The right ventricle, on the other hand, pumps blood to the lungs and doesn't need as much pressure to do so. Therefore, the left ventricle is responsible for generating the highest pressure in the heart.

Question 20

The _____ conducts action potentials down the atrioventricular septum.
A) Bachmann bundle
B) bundle of His
C) sinoatrial node
D) atrioventricular node

Accepted Answer

The bundle of His conducts action potentials down the atrioventricular septum, separating into the left and right bundle branches to continue the signal down to the Purkinje fibers and into the ventricles. The Bachmann bundle conducts action potentials between the two atria, while the sinoatrial node generates the initial action potential and the atrioventricular node delays the signal to allow for proper atrial contraction before ventricular contraction.

Quiz 22: Structure and Function of the Cardiovascular and Lymphatic Systems

The _____ period follows depolarization of the myocardium and represents a period during which no new cardiac potential can be propagated.

A 52-year-old female is admitted to the cardiac unit with a diagnosis of pericarditis. She asks the nurse to explain where the infection is. In providing an accurate description, the nurse states that the pericardium is:

Depolarization of a cardiac muscle cell occurs as the result of:

Oxygenated blood flows through the:

The chamber that receives blood from the systemic circulation is the:

In a normal electrocardiogram, the P-R interval represents:

The _____ represents the sum of all ventricular muscle cell depolarization.

A 65-year-old male develops blockage in the pulmonary artery. As a result, blood would first back up into the:

A 50-year-old female received trauma to the chest that caused severe impairment of the primary pacemaker cells of the heart. Which of the following areas received the greatest damage?

The _____ artery travels down the interventricular septum and delivers blood to portions of the left and right ventricle.

A function of the pericardium is to:

A 54-year-old male is diagnosed with left bundle branch block. Which of the following structures would not receive an electrical impulse?

A 20-year-old male underwent an echocardiogram to assess chest pain. Results revealed a congenital defect in papillary muscles. Which of the following would occur?

A 13-year-old female took a weight loss drug that activated the sympathetic nervous system. Which of the following would be expected?

Venous blood from the coronary circulation drains into the:

The coronary ostia (the openings to the coronary arteries) are found in the:

A 65-year-old male is transported to the ER for chest pain. An electrocardiogram reveals a prolonged QRS interval. This result indicates:

_____ are the anchors of the atrioventricular valves.

The chamber of the heart that generates the highest pressure is the:

The _____ conducts action potentials down the atrioventricular septum.