A&P ch 18

Define cardiac regurgitation. (Module 18.7A)

Cardiac regurgitation is the backflow of blood into the atria when the ventricles contract.

What is the first phase of the cardiac cycle?

atrial systole

The bicuspid, or mitral, valve is located

between left atrium and left ventricle

Which valve(s) close(s) during ventricular contraction?

both AV valves

The function of the atrium is to

collect blood and pump blood to the ventricle

The P wave of the electrocardiogram is a signal from

depolarization of the atria.

As the heart rate slows, ________ get(s) longer.

diastole

The ________ is the volume of blood in a ventricle at the beginning of systole.

end-diastolic volume Submit

The ________ separate(s) the two ventricles.

interventricular septum

The circumflex branch and the anterior interventricular artery are branches of the

left coronary artery. Submit

The left border of the heart is formed by the

left ventricle to the left atrium

The ________ has a greater workload than the ________.

left ventricle; right ventricle

The coronary sulcus is a groove that

marks the border between the atria and ventricles.

When the semilunar valves close, the AV valves then

open

The cavity that contains only the heart is the

pericardial cavity

Blood leaves the right ventricle by passing through the

pulmonary valve.

The right atrium receives blood from all of the following except the

pulmonary veins.

The right ventricle pumps blood to the

right and left lungs

Coronary veins empty into the

right atrium

The normal pacemaker of the heart is located in

the sinoatrial node.

If the connection between the SA node and AV node becomes blocked,

the ventricles will beat more slowly.

The cavity that contains the lungs, the heart, great vessels, thymus, esophagus, and trachea is called the

thoracic cavity.

Muscular ridges on the inner surface of the ventricles are called

trabeculae carneae.

Compare arteriosclerosis with atherosclerosis. (Module 18.8A)

Arteriosclerosis is any thickening and toughening of arterial walls; atherosclerosis is a type of arteriosclerosis characterized by changes in the endothelial lining and the formation of fatty deposits (plaque) in the tunica media. Submit

Why does tetany not occur in cardiac muscle? (Module 18.11A)

Tetany does not occur because cardiac muscle has a long refractory period that continues until relaxation is well under way so summation cannot occur, and thus tetany cannot occur.

Compare the base of the heart with the apex. (Module 18.1B)

The base of the heart is the superior portion where the largest veins and arteries are attached. The apex of the heart is located on the inferior aspect of the heart.

The ________ separate(s) the two atria.

interatrial septum

Blood returning to the heart from the pulmonary circuit first enters the

left atrium.

Blood is supplied to the left atrium by the

left coronary artery

Cardiac muscle cells are __________.

mechanically, chemically, and electrically connected to one another.

Heart rate is controlled by neurons of the cardiovascular center located in the

medulla oblongata

The interventricular sulci and coronary sulcus contain all of the following except

nerves.

Describe the location and position of the heart. (Module 18.1A)

The heart is located near the anterior chest wall, directly behind the sternum.

Describe the heart's location in the body.

The heart is surrounded by the pericardium in the anterior mediastinum, deep to the sternum and superior to the diaphragm.

If the cells of the SA node failed to function, how would the heart rate be affected? (Module 18.12B)

The heart would beat slower because the AV node would be the pacemaker.

Why is the left ventricle more muscular than the right ventricle? (Module 18.6A)

The left ventricle must generate enough force to propel blood through the systemic circuit, whereas the right ventricle must generate only enough force to propel blood the short distance from the heart to the lungs in the pulmonary circuit.

Define mediastinum. (Module 18.2A)

The mediastinum is the region between the two pleural cavities that contains the heart, along with the great vessels, thymus, esophagus, and trachea.

The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as

cardiac tamponade.

The first heart sound ("lubb") is associated with

closing of the mitral valve

The first blood vessels to branch from the aorta are the ________ arteries.

coronary

The ________ is the amount of blood in a ventricle after it has contracted and before it begins to refill.

end-systolic volume Submit

Averaged over a few heartbeats, venous return is ________ cardiac output.

equal to

There are ________ pulmonary veins.

four

________ is to contraction as ________ is to relaxation.

Systole; diastole

The heart beats approximately ________ times each day.

100,000

The heart pumps approximately ________ milliliters of blood each minute.

6,000

Which ECG event demonstrates the depolarization of the atria?

P wave

Why is ventricular fibrillation fatal?

Ventricular fibrillation is fatal because the ventricles quiver and do not pump blood to the systemic circulation.

Intercalated discs serve to transfer all of the following from cell to cell except

Z-lines.

What factor would decrease stroke volume?

an increase in afterload

What superficial landmark identifies the boundary between the left and right ventricles?

anterior interventricular sulcus

The left ventricle pumps blood to the

aorta

Name the four chambers of the heart. (Module 18.1C)

left atrium, left ventricle, right atrium, right ventricle

The amount of blood returning to the heart is the

venous return

The wall(s) of the ________ rest(s) on the diaphragm.

right ventricle

Identify the correct sequence for blood flow through the heart.

right ventricle, through pulmonary valve, pulmonary trunk, pulmonary arteries

The volume of blood ejected from each ventricle during a contraction is called the

stroke volume.

A faster-than-normal heart rate is called

tachycardia

The relaxation phase of the lower chambers of the heart is called

ventricular diastole.

The T wave on an ECG tracing represents

ventricular repolarization

During which phase of the cardiac cycle is the blood pumped to the body?

ventricular systole

During ventricular systole, the

AV valves are closed

Define electrocardiogram. (Module 18.13A)

An electrocardiogram is a recording of the electrical activity of the heart. Submit

Define autorhythmicity.

Autorhythmicity is the ability of the heart to contract without neural or hormonal stimulation. Submit

Compare bradycardia with tachycardia. (Module 18.14A)

Bradycardia is a heart rate below 60 beats per minute and tachycardia is a heart rate above 100 beats per minute.

The ________ deliver(s) blood to the myocardium.

both right coronary artery and left coronary artery

What is coronary ischemia? (Module 18.8B)

Coronary ischemia is a condition in which the blood supply of the coronary arteries is reduced. Submit

Define heart failure. (Module 18.16A)

Heart failure is a condition where the heart can no longer meet the oxygen and nutrient demands of peripheral tissues.

Which of these would cause stroke volume to increase?

both when venous return is increased and when diastolic blood pressure is decreased

What do semilunar valves prevent? (Module 18.7C)

Semilunar valves prevent backflow of blood into the ventricles. Submit

List the phases of the cardiac cycle.

atrial systole, atrial diastole, ventricular systole, ventricular diastole

The contraction phase of the upper chambers of the heart is called

atrial systole.

The earlike extension of the atrium is the

auricle

The heart is innervated by ________ nerves.

both parasympathetic and sympathetic

Damage to the semilunar valve on the right side of the heart would affect blood flow to which vessel? (Module 18.6B)

pulmonary trunk

As blood leaves the right ventricle, it passes through the ________ and then into the pulmonary trunk.

pulmonary valve

List the three stages of an action potential in a cardiac muscle cell. (Module 18.11B)

rapid depolarization, plateau, and repolarization

During the T wave of the electrocardiogram, the ventricles are electrically ________ and functionally ________.

repolarizing; relaxing

The anterior view of the heart is dominated by which chambers? (Module 18.4A)

right atrium and right ventricle