Question 1

________ is the term used to indicate a heart rate that is slower than normal.

Accepted Answer

Bradycardia is the term used to indicate a heart rate that is slower than normal. Cardiac tamponade is a condition in which there is accumulation of fluid in the pericardial sac and it compresses the heart, leading to decreased cardiac output. Angina is chest pain due to reduced blood flow to the heart muscle. Tachycardia is a term that indicates a heart rate that is faster than normal. Coronary ischemia is a condition in which there is reduced blood flow to the heart muscle due to narrowing of the coronary arteries.

Question 2

The sinoatrial node, or cardiac pacemaker, is ________.

Accepted Answer

The sinoatrial node, or cardiac pacemaker, is embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava. It is responsible for initiating the electrical impulses that regulate the heart rate and rhythm.

Question 3

Which of the following is a major component of the cardiac conduction system located in the interventricular septum, and extends toward the apex of the heart?

Accepted Answer

The bundle branches are a major component of the cardiac conduction system located in the interventricular septum and extend toward the apex of the heart, conducting electrical impulses to the ventricles.

Question 4

Which branch(es)of the right coronary artery extends toward the apex along the anterior surface of the right ventricle of the heart?

Accepted Answer

The right marginal branch extends toward the apex along the anterior surface of the right ventricle.

Question 5

Which of the following associations is correct?

Accepted Answer

The mitral valve is located between the left atrium and left ventricle, making it an atrioventricular valve.

Answer: E
 The pulmonary valve is located between the right ventricle and pulmonary artery, making it a semilunar valve. The chordae tendineae are located in the ventricles and attach to the cusps of the atrioventricular valves (the mitral and tricuspid valves). Therefore, there is no association between the pulmonary valve and chordae tendineae.

Therefore, the correct choice is A.

Question 6

Which coronary vein receives blood from the posterior surfaces of the right atrium and ventricle?

Accepted Answer

The small cardiac vein runs along the heart's right margin, collecting blood from the posterior surfaces of the right atrium and ventricle before draining into the coronary sinus.

Question 7

Structures in the heart that carry electrical signals from the SA node to the AV node are called ________.

Accepted Answer

The structures in the heart that carry electrical signals from the SA node to the AV node are called internodal pathways.

Question 8

If the cusps of an atrioventricular valve are damaged or functionally impaired so that they do not close completely during the normal point in the cardiac cycle, blood may flow backwards. This is called ________.

Accepted Answer

When the cusps of an atrioventricular valve do not close completely during the normal point in the cardiac cycle, blood may flow backwards. This is called regurgitation. Ischemia refers to lack of blood flow to tissue, thrombosis refers to blood clots, automaticity refers to the ability of certain cells to generate their own electrical activity, and nodal depolarization refers to the electrical activity of the heart's pacemaker cells. None of these options describe the situation of defective valve cusps that results in blood flowing backwards.

Question 9

Which vessel gives rise to a circumflex branch and an anterior interventricular branch?

Accepted Answer

The left coronary artery gives rise to the circumflex branch (which supplies the lateral walls of the left ventricle and left atrium) and the anterior interventricular branch (which supplies the interventricular septum and anterior walls of the ventricles).

Question 10

Which of the following is true regarding contractions of the heart?

Accepted Answer

Cardiac contractions are coordinated by specialized conducting cells, known as the cardiac conduction system, which distribute the stimulus to cardiac muscle cells. This ensures that the contractions occur in a precise, coordinated sequence, allowing for efficient pumping of blood. The rate of contractions is also established by the conducting fibers within this system. The atria do contract first, but only by a fraction of a second before the ventricles.

Question 11

Valves of the heart open and close due to ________.

Accepted Answer

Valves of the heart open and close due to pressure changes. When the pressure on one side of the valve is greater than the pressure on the other side, the valve opens. When the pressure on the other side is greater, the valve closes. The pressure changes are caused by the contracting and relaxing of the heart muscle.

Question 12

The inherent ability of cardiac muscle tissue to contract in the absence of neural or hormonal stimulation is called ________.

Accepted Answer

The inherent ability of cardiac muscle tissue to contract in the absence of neural or hormonal stimulation is called autorhythmicity.

Question 13

There are many interconnections between the arterial branches of the coronary circulation, which function to maintain a constant blood supply to the muscle of the heart. These connections are called ________.

Accepted Answer

The connections between the arterial branches of the coronary circulation that maintain a constant blood supply to the heart muscle are called anastomoses. This allows for blood to flow through alternate pathways in case of blockages or decreased blood flow in a particular vessel. Syncytium, intercalation, prolapse, and autorhythmicity are not related to the interconnections between coronary arteries.

Question 14

The rapidly depolarizing cells, called pacemaker cells, are found in the ________, which is embedded in the posterior wall of the right atrium.

Accepted Answer

The statement describes the SA (sinoatrial) node, which is located in the posterior wall of the right atrium and is responsible for initiating the electrical impulses that regulate the heartbeat. Choice A describes a part of the heart's electrical conduction system that helps to distribute impulses to the ventricles. Choice B describes a junctional area between the atria and ventricles that helps to delay impulses and coordinate their arrival in the ventricles. Choice C describes another part of the heart's electrical conduction system that helps to distribute impulses to the ventricles. Choice D describes the pathways that connect the SA node to the AV node.

Question 15

Which of the following is true of the coronary arteries?

Accepted Answer

The coronary arteries originate at the base of the ascending aorta and are the first branches off this vessel, providing oxygenated blood to the heart muscle.

Answer: B
 Although the heart muscle is relatively small compared to other organs, it requires a large supply of oxygen to function properly. The coronary arteries are responsible for delivering this oxygen-rich blood to a small portion of the cardiac muscle.

Therefore, both choices B and C are true statements about the coronary arteries.

Question 16

The right border of the heart is supplied by the ________.

Accepted Answer

The right marginal artery supplies the right border of the heart.

Question 17

The left atrium receives oxygen-rich blood from the ________.

Accepted Answer

The left atrium receives oxygen-rich blood from the pulmonary veins, which bring oxygenated blood from the lungs.

Question 18

Which of the following vessels drains the anterior surface of the right ventricle and empties directly into the right atrium?

Accepted Answer

The anterior cardiac veins drain the anterior surface of the right ventricle and empty directly into the right atrium.

Question 19

Which event occurs during the first phase of ventricular systole?

Accepted Answer

During the first phase of ventricular systole, the atrioventricular valves (mitral and tricuspid valves) close to prevent the backflow of blood into the atria, which is why the chordae tendineae become tense, not loose, to support the closed position of these valves. The semilunar valves (aortic and pulmonary valves) have not yet opened because the pressure in the ventricles has not exceeded the pressure in the arteries. The volume of the ventricles does not change dramatically at this initial stage; this phase is known as isovolumetric contraction because the volume within the ventricles remains constant as the pressure increases. Blood exits the ventricles during the later phase of ventricular systole, not the first phase.

Question 20

Which of the following structures is a large, thin-walled vein that lies in the posterior portion of the coronary sulcus?

Accepted Answer

The coronary sinus is a large, thin-walled vein located in the posterior portion of the coronary sulcus, which collects blood from the heart muscle (myocardium) and returns it to the right atrium.

Quiz 21: The Cardiovascular System: The Heart