chapter 18 homework

Compare the volume of blood each circuit receives from contraction of the ventricles.

Both circuits receive the same volume of blood

Which parts of the following statement are true? The AV node delivers the stimulus to the AV bundle, located within the interventricular septum.

Both parts of the statement are true

Veins are more prone to inappropriate stretching and twisting than arteries, because

Veins have thinner walls than arteries

What is coronary ischemia?

a condition in which the blood supply of the coronary arteries is reduced

Which of the following does NOT contribute to the partial or complete blockage of the coronary arteries that causes coronary ischemia?

a stent

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

anterior interventricular sulcus

The left ventricle pumps blood to the

aorta

The inferior point of the heart is called the

apex

Which of the following descriptions matches the phrase "near the left fifth intercostal space"?

apex of the heart

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

both AV valves

The ________ separate(s) the two ventricles.

interventricular septum

Define cardiac regurgitation

is the backflow of blood into the atria when the ventricles contract

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.

isovolumetric contraction, ventricular ejection, isovolumetric relaxation

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

left coronary artery

Which vessel(s) supplies/supply the left ventricle, left atrium, and the interventricular septum?

left coronary artery

Most of the mass of the heart lies to the ________ the midline.

left of

Which chamber pumps oxygenated blood out the aorta to the systemic circuit?

left ventricle

The ________ has a greater workload than the ________.

left ventricle; right ventricle

The pulmonary arteries carry blood to the

lungs

Which structure provides a rapid-conduction path that tenses the papillary muscles before the ventricular myocardium contracts, preventing "slamming" of the right AV cusps?

moderator band

The muscle layer of the heart is the

myocardium

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

nerves

When the semilunar valves close, the AV valves then

open

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

pulmonary veins

Compared to the right ventricle, the left ventricle has all the following characteristics except that it

pumps a greater volume

If a patient's tricuspid valve was leaking during systole, what would happen?

regurgitation back into the right atrium

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

repolarizing; relaxing

The right ventricle pumps blood to the

right and left lungs

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

right atrium

Which chamber receives blood from the superior and inferior vena cavae?

right atrium

The marginal branch and posterior interventricular branch are branches of the

right coronary artery

The ________ deliver(s) blood to the myocardium.

right coronary artery and left coronary artery

The pulmonary semilunar valve prevents backward flow into the

right ventricle

Which heart chamber pumps unoxygenated blood out the pulmonary trunk?

right ventricle

Identify the correct sequence for blood flow through the heart.

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

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

thoracic cavity

Blood flowing into the heart from the venae cavae flows next through the ________ valve.

tricuspid

The heart is actually (one, two, or three) pumps?

two pumps

The pulmonary veins carry blood to the

heart

David suffers from a prolapsed mitral valve. This condition would cause

increased effort by the left ventricle and regurgitation

The ________ separate(s) the two atria.

interatrial septum

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

left atrium

Which heart chamber receives blood from the lungs?

left atrium

Which heart chamber receives blood from the pulmonary veins?

left atrium

Name the four chambers of the heart.

left atrium, left ventricle, right atrium, right ventricle

The coronary sulcus is a groove that

marks the border between the atria and ventricles

Cardiac muscle cells are __________.

mechanically, chemically, and electrically connected to one another

The earlike extension of the atrium is the

auricle

From superficial to deep, name the layers of the heart wall.

pericardium, myocardium, endocardium

What do semilunar valves prevent?

prevent backflow of blood into the ventricles

Damage to the semilunar valve on the right side of the heart would affect blood flow to which vessel?

pulmonary trunk

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

pulmonary valve

Blood leaves the right ventricle by passing through the

pulmonary valve

Muscular ridges on the inner surface of the ventricles are called

trabeculae carneae

Which of the following statements most accurately defines what is happening during the second phase of ventricular systole of the cardiac cycle?

Blood is being ejected from the ventricles through open semilunar valves

In an ECG recording, which of the following coincides with ventricular repolarization?

T-wave

Compare the base of the heart with the apex

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.

Which structures collect blood from the myocardium, and into which heart chamber does this blood flow?

Coronary veins collect blood from the myocardium and carry it to the right atrium

Describe the location and position of the heart.

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

Which statement is correct regarding the intrinsic heart rate?

During parasympathetic stimulation, acetylcholine released by parasympathetic neurons opens chemically gated potassium channels in the plasma membrane

Which of the following is correct about the filling of the ventricles?

Most blood flows passively into the ventricles through open AV valves

Depolarization of the atria corresponds to the ECG's

P wave

In the non-exercising heart, which event of the cardiac cycle lasts the longest?

atrial diastole

When the ventricles contract, what pushes the cusps of the AV together, closing them to prevent backflow from the ventricles into the atria?

blood from inside the ventricles

There are ________ pulmonary veins.

4

Complications related to arteriosclerosis account for roughly ________ percent of deaths in the United States.

50

The first heart sound is heard when the

AV valves close

How would properly functioning valves prevent varicose veins?

Valves prevent backward flow of blood

The bicuspid, or mitral, valve is located

between the left atrium and left ventricle

The ________ valve prevents backward flow into the left atrium.

bicuspid

The P wave of the electrocardiogram is a signal from

depolarization of the atria

Arteriosclerosis can lead to all of the following except

diabetes

What causes the aortic semilunar valve to close?

greater pressure in the aorta than in the left ventricle

Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.

ventricular diastole

The mitral valve closing is associated with all of the following except

when the left atrial pressure exceeds the left ventricular pressure

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

z-lines

Increased pressure in the ventricles would close what valve(s)?

AV valves only

Compare arteriosclerosis with atherosclerosis

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

Which event does NOT happen during ventricular diastole?

Atrioventricular valves close because of the contracting ventricles

Why is it important that cardiac tissue contain many mitochondria and capillaries?

Cardiac tissue is metabolically active and dependent on mitochondrial activity to use aerobic respiration to generate ATP and capillaries provide the oxygen and nutrients for this process

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.

Pressure in the atria would be greater than the pressure in the ventricles

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.

QRS complex

Depolarization of the ventricles is represented on an electrocardiogram by the

QRS complex

Comparing the left ventricle with the right ventricle, which of the following is true?

The left ventricle does more work than the right ventricle

Why is the left ventricle more muscular than the right ventricle?

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

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

cardiac tamponade

The cusps (leaflets) of atrioventricular valves attach directly to

chordae tendineae

Which artery curves to the left around the coronary sulcus, eventually meeting and fusing with small branches of the right coronary artery?

circumflex artery

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

closing of the mitral valve

The function of the atrium is to

collect blood and pump blood to the ventricle

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

coronary

Blood is supplied to the myocardium by

coronary arteries

The great and middle cardiac veins drain blood into the

coronary sinus

Which exterior heart structure returns "used" blood collected from the heart muscle itself (myocardium) back into the flow of blood to be delivered to the pulmonary circuit?

coronary sinus

Given the description of Tran's varicose veins, what is the name of one of the affected vessels in his legs?

great saphenous vein

The atrioventricular valves permit blood flow

in one direction only

Which description correctly describes the location of the heart?

in the mediastinum, superior to the diaphragm