Question 1

An ECG provides direct information about valve function.

Accepted Answer

An ECG measures the electrical activity of the heart and can detect irregularities in heart rhythm, but it does not provide direct information about valve function. Other imaging tests such as echocardiogram or MRI are required to assess valve function.

Question 2

The left ventricular wall of the heart is thicker than the right wall in order to ________.
A) accommodate a greater volume of blood
B) expand the thoracic cage during diastole
C) pump blood with greater pressure
D) pump blood through a smaller valve

Accepted Answer

The left ventricular wall is thicker than the right because it needs to pump blood with greater pressure in order to push the blood out into the systemic circulation. The right ventricle only needs to pump blood to the lungs, which is a much shorter distance and therefore requires less pressure. Therefore, choice C is the best answer.

Question 3

The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the AV valve flaps.

Accepted Answer

The answer of The papillary muscles contract after the other...

Question 4

Hemorrhage with a large loss of blood causes ________.
A) a lowering of blood pressure due to change in cardiac output
B) a rise in blood pressure due to change in cardiac output
C) no change in blood pressure but a slower heart rate
D) no change in blood pressure but a change in respiration

Accepted Answer

Hemorrhage with a large loss of blood causes a decrease in blood volume, which leads to a decrease in cardiac output and ultimately a lowering of blood pressure.

Question 5

Damage to the ________ is referred to as heart block.
A) SA node
B) AV valves
C) AV bundle
D) AV node

Accepted Answer

Heart block refers to a condition where the electrical impulse that controls heartbeat is delayed or blocked as it travels from the atria to the ventricles. This delay or block can occur at different points in the pathway, but most often it is at the AV node. Damage to the SA node or AV valves would not typically cause heart block, and damage to the AV bundle can cause heart block but it is less common than when it occurs in the AV node.

Question 6

Which of the events below does not occur when the semilunar valves are open?
A) Ventricles are in diastole.
B) Blood enters pulmonary arteries and the aorta.
C) AV valves are closed.
D) Ventricles are in systole.

Accepted Answer

When the semilunar valves are open, blood enters the pulmonary arteries and the aorta which occurs during ventricular systole, not diastole. Therefore, the correct answer is A - ventricles are in diastole.

Question 7

Blood within the pulmonary veins returns to the ________.
A) right atrium
B) left atrium
C) right ventricle
D) left ventricle

Accepted Answer

Blood within the pulmonary veins returns to the left atrium. This is because the pulmonary veins carry oxygenated blood from the lungs back to the heart, and the left atrium receives this blood before it is pumped out to the rest of the body by the left ventricle.

Question 8

As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve.

Accepted Answer

As pressure in the aorta rises due to atherosclerosis, the aortic valve becomes stiffer and more resistant to opening, requiring increased ventricular pressure to open it.

Question 9

The left side of the heart pumps the same volume of blood as the right.

Accepted Answer

The left side of the heart pumps the same volume of blood as the right because they are connected by the pulmonary veins and arteries, creating a closed circulatory system. This means that blood flows continuously from the heart to the lungs and back to the heart, and then out to the rest of the body and back to the heart again. Therefore, the same amount of blood must be pumped from the left and right sides of the heart.

Question 10

Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues.

Accepted Answer

Congestive heart failure is a condition where the heart is unable to pump blood efficiently, leading to inadequate delivery of blood to the body tissues.

Question 11

Auricles slightly increase blood volume in the ventricles.

Accepted Answer

The answer of Auricles slightly increase blood volume in the...

Question 12

Normal heart sounds are caused by which of the following events?
A) excitation of the SA node
B) closure of the heart valves
C) friction of blood against the chamber walls
D) opening and closing of the heart valves

Accepted Answer

Normal heart sounds are primarily caused by the closure of the heart valves, specifically the atrioventricular valves (producing the first heart sound, S1) and the semilunar valves (producing the second heart sound, S2).

Question 13

The "lub" sounds of the heart are valuable in diagnosis because they provide information about the function of the heart's pulmonary and aortic valves.

Accepted Answer

The answer of The "lub" sounds of the heart are...

Question 14

The condition where fluid compresses the heart and limits its ability to contract is called ________.
A) pericarditis
B) cardiac tamponade
C) myocardial infarction
D) angina pectoris

Accepted Answer

Cardiac tamponade occurs when fluid builds up in the pericardial sac around the heart, putting pressure on the heart and limiting its ability to contract effectively. Pericarditis involves inflammation of the pericardium, but does not necessarily involve fluid buildup. Myocardial infarction (heart attack) and angina pectoris both involve blockages or restrictions of blood flow to the heart, but do not involve fluid buildup around the heart.

Question 15

Tissues damaged by myocardial infarction are replaced by connective tissue.

Accepted Answer

Connective tissue is formed during the healing process after myocardial infarction in order to provide structural support to the damaged area, but it does not replace the original cardiac muscle tissue. The formation of connective tissue can lead to a decrease in cardiac function and an increased risk of future cardiac events.

Question 16

Blood in the heart chambers provides some nutrients to the heart muscle cells.

Accepted Answer

Blood in the heart chambers contains oxygen and nutrients, including glucose and electrolytes, which are necessary for the heart muscle cells to function properly.

Question 17

Chronic release of excess thyroxine can cause a sustained increase in heart rate and a weakened heart.

Accepted Answer

Chronic release of excess thyroxine can cause hyperthyroidism, which can lead to an increase in heart rate and weakened heart muscle, among other symptoms.

Question 18

Autonomic regulation of heart rate is via two reflex centers found in the pons.

Accepted Answer

Autonomic regulation of heart rate is primarily controlled by the medulla oblongata, not the pons. The medulla oblongata contains the cardiac control center, which regulates heart rate through the sympathetic and parasympathetic nervous systems.

Question 19

The P wave of a normal electrocardiogram indicates ________.
A) ventricular repolarization
B) ventricular depolarization
C) atrial repolarization
D) atrial depolarization

Accepted Answer

The P wave of a normal electrocardiogram indicates atrial depolarization.

Question 20

Arterial blood supply to heart muscle is continuous whether the heart is in systole or diastole.

Accepted Answer

During systole, the contraction of the heart muscle compresses the coronary arteries and temporarily restricts blood flow. Blood flow to the heart muscle primarily occurs during diastole when the heart is relaxed and the coronary vessels are open and unobstructed.

Quiz 17: The Cardiovascular System: the Heart

An ECG provides direct information about valve function.

The left ventricular wall of the heart is thicker than the right wall in order to ________.

The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the AV valve flaps.

Hemorrhage with a large loss of blood causes ________.

Damage to the ________ is referred to as heart block.

Which of the events below does not occur when the semilunar valves are open?

Blood within the pulmonary veins returns to the ________.