🌟Anatomy and Physiology Chapter 20 (The Heart)

The P wave of the electrocardiogram is closely followed by __________.

a) contraction of both atria

b) contraction of the left atrium

c) relaxation of both atria

d) contraction of the right atrium

a) contraction of both atria

The volume of blood remaining in the ventricle as diastole begins is called the __________.

a) end-diastolic volume

b) end-systolic volume

c) cardiac reserve

d) stroke volume

b) end-systolic volume

If you know both the heart rate and stroke volume, you can calculate the __________.

a) ejection fraction

b) end-systolic volume

c) cardiac output

d) end-diastolic volume

c) cardiac output

The epicardium is also known as the __________.

a) visceral pericardium

b) myocardium

c) endocardium

d) parietal pericardium

a) visceral pericardium

Which of these is an important difference between cardiac muscle and skeletal muscle?

a) Skeletal muscle is striated.

b) Cardiac muscle lacks troponin.

c) Cardiac muscle contracts spontaneously.

d) Cardiac muscle can't be tetanized.

d) cardiac muscle can't be tetanized

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

a) pulmonary valve

b) left atrium

c) pulmonary trunk

d) right atrium

b) left atrium

The papillary muscles function to __________.

a) close the AV valves

b) push blood from the atria into the ventricles

c) prevent the AV valves from reversing into the atria

d) eject blood from the ventricles

c) prevent the AV valves from reversing into the atria

The __________ valve prevents backward flow of blood into the left ventricle.

a) tricuspid

b) bicuspid

c) aortic

d) pulmonic

c) aortic

Blood flowing in the vena cava will next enter the __________.

a) left ventricle

b) right ventricle

c) left atrium

d) right atrium

d) right atrium

Excess fluid in the ________ causes cardiac tamponade.

a) both atria

b) left ventricle

c) pericardial cavity

d) apex of heart

e) visceral pericardium

c) pericardial cavity

Intercalated discs serve to transfer ________ from cell to cell.

a) action potentials

b) electrical signals

c) the force of contraction

d) ionic currents

e) All of the answers are correct.

e) All of the answers are correct

Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them?

a) Cardiac muscle cells branch.

b) Skeletal muscle cells lack intercalated discs.

c) Cardiac muscle cells are smaller in size.

d) Cardiac muscle cells have a single, centered nucleus.

e) Cardiac muscle cells lack transverse tubules.

e) Cardiac muscle cells lack transverse tubules.

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

a) conus arteriosus.

b) left atrium.

c) left ventricle.

d) right ventricle.

e) right atrium.

e) right atrium

The cusps (leaflets) of atrioventricular valves attach directly to

a) interatrial septa.

b) papillary muscles.

c) trabeculae carneae.

d) coronary sulci.

e) chordae tendineae.

e) chordae tendineae

The right ventricle pumps blood to the

a) right and left lungs.

b) aorta.

c) left atrium.

d) right atrium.

e) left ventricle.

a) right and left lungs

The left ventricle pumps blood to the

a) pulmonary circuit.

b) right ventricle.

c) aorta.

d) right atrium.

e) lungs.

c) aorta

When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n)

a) myocardial infarction.

b) coronary spasm.

c) angina pectoris.

d) coronary thrombosis.

e) pulmonary embolism.

d) coronary thrombosis

The first heart sound is heard when the

a) AV valves open.

b) semilunar valves close.

c) blood enters the aorta.

d) AV valves close.

e) atria contract.

d) AV valves close

The pulmonary arteries carry blood to the

a) heart.

b) liver.

c) intestines.

d) brain.

e) lungs

e) lungs

The pulmonary veins carry blood to the

a) liver.

b) intestines.

c) brain.

d) lungs.

e) heart.

e) heart

The foramen ovale in the fetal heart is located in the

a) left atrium.

b) interatrial septum.

c) left ventricle.

d) right atrium.

e) right ventricle.

b) interatrial septum

Blood is supplied to the myocardium by

a) the coronary sinus.

b) contact with blood in the pumping chambers.

c) the coronary arteries.

d) arteries that branch off the subclavian arteries.

e) arteries that branch from the pulmonary arteries.

c) coronary arteries

Heart rate is controlled by __________.

a) the phrenic nerves

b) both the right vagus and sympathetic nerves

c) sympathetic nerves in the cardiac plexus

d) the right vagus nerve

b) both the right vagus and sympathetic nerves

The rapid depolarization phase in the ventricular action potential appears in the electrocardiogram as the __________.

a) QRS complex

b) P wave

c) PR segment

d) T wave

a) QRS complex

The plateau phase of the ventricular action potential corresponds to the __________ phase of the electrocardiogram.

a) PR interval

b) ST segment

c) T wave

b) ST segment

During the plateau phase of the cardiac action potential, which ion is entering the cardiac muscle cell?

a) hydrogen

b) potassium

c) calcium

d) sodium

c) calcium

The conducting system in the heart begins in the __________.

a) AV bundle

b) AV node

c) SA node

d) Purkinje fibers

c) SA node

The ________ deliver(s) blood to the myocardium.

a) carotid arteries

b) coronary sinus

c) superior vena cava

d) cardiac veins

e) coronary arteries

e) coronary arteries

Blood is supplied to the left atrium by the

a) phrenic arteries.

b) right coronary artery.

c) brachiocephalic artery.

d) left coronary artery.

e) pulmonary arteries.

d) left coronary artery

The bicuspid or mitral valve is located

a) in the opening of the aorta.

b) where the venae cavae join the right atrium.

c) between the left atrium and left ventricle.

d) between the right atrium and right ventricle.

e) in the opening of the pulmonary trunk.

c) between the left atrium and left ventricle

The function of an atrium is to

a) collect blood.

b) pump blood to the lungs.

c) collect blood then pump it to the ventricle.

d) pump blood to the ventricle.

e) pump blood into the systemic circuit.

c) collect blood then pump it to the ventricle

The normal pacemaker of the heart is located in

a) the sinoatrial node.

b) the Purkinje fibers.

c) both the left and right ventricles.

d) the atrioventricular node.

e) the wall of the left ventricle.

a) the sinoatrial node

If the pacemaker cells in the SA node become more permeable to potassium ions, the

a) cells will depolarize.

b) cells will hyperpolarize.

c) heart rate will decrease and cells will hyperpolarize.

d) heart rate will decrease.

e) heart rate will increase

c) heart rate will decrease and cells will hyperpolarize

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

a) the ventricles will beat more slowly.

b) the atria will contract more forcefully.

c) the ventricles will beat faster.

d) the ventricular beat will remain unchanged.

e) cardiac output will increase.

a) the ventricles will beat more slowly

Depolarization of the ventricles is represented on an electrocardiogram by the

a) QRS complex.

b) S wave.

c) P wave.

d) T wave.

PR complex.

a) QRS complex

What is the relaxed state of the ventricle called?

a) systole

b) ventricular filling

c) ventricular ejection

d) diastole

d) diastole

The one-way nature of the left AV valve prevents blood flow from _________.

a) the left ventricle to the aorta

b) the left atrium to the left ventricle

c) the left ventricle to the left atrium

d) the aorta to the left ventricle

c) the left ventricle to the left atrium

The closing of the left AV valve occurs near the beginning of __________.

a) atrial systole

b) ventricular systole

c) isovolumetric relaxation

d) ventricular diastole

b) ventricular systole

The majority of ventricular filling occurs while the ventricles and atria are in what state(s)?

a) ventricular diastole and atrial systole

b) ventricular systole and atrial systole

c) ventricular and atrial diastole

d) ventricular systole and atrial diastole

c) ventricular and atrial diastole

Which of the following most correctly describes end-diastolic volume?

a) the volume of the ventricle when it is most full

b) the volume of the ventricle when it is least full

c) the increase in ventricular volume during atrial systole

d) the volume of the ventricle at the end of atrial diastole

a) the volume of the ventricle when it is most full

Left ventricular filling occurs __________.

a) while the AV valve is open

b) during isovolumetric relaxation

c) during ventricular systole

d) while the semilunar valve is open

a) while the AV valve is open

Heart valves are in what state during isovolumetric contraction?

a) The AV valves and semilunar valves are open.

b) The AV valves and semilunar valves are closed.

c) The AV valves are closed, and the semilunar valves are open.

d) The AV valves are open, and the semilunar valves are closed.

b) The AV valves and semilunar valves are closed

The decrease in left ventricular pressure at the end of ventricular systole causes __________.

a) the semilunar valve to close

b) the semilunar valve to open

c) the AV valve to close

d) isovolumetric contraction

a) the semilunar valve to close

Ventricular diastole begins with the closing of the semilunar valves. What phase of the cardiac cycle happens between this event and the later opening of the AV valves?

a) isovolumetric relaxation

b) atrial systole

c) ventricular ejection

d) isovolumetric contraction

a) isovolumetric relaxation

A heart murmur might be caused by

a) aortic valve insufficiency.

b) pulmonic valve insufficiency.

c) mitral valve insufficiency.

d) swirling of blood in the ventricle.

e) All of the answers are correct.

e) All of the answers are correct

During ventricular systole, the

a) atria are contracting.

b) blood is entering the ventricles.

c) pressure in the ventricles remains constant.

d) pressure in the aorta remains constant.

e) AV valves are closed.

e) AV valves are closed

Which of the following will not increase heart rate?

a) increased parasympathetic stimulation of the SA node

b) faster rise of the pacemaker potential

c) increased levels of circulating epinephrine

d) increased sympathetic stimulation of the SA node

a) increased parasympathetic stimulation of the SA node

Which of these changes will not increase cardiac output?

a) increased stroke volume

b) increased heart rate

c) increased end-diastolic volume

d) increased afterload

d) increased afterload

An increase in the rate of action potentials from baroreceptors will trigger a reflex to

a) decrease in blood pressure.

b) decrease in heart rate.

c) increase in heart rate.

d) both decrease heart rate and decrease pressure.

e) both increase heart rate and increase pressure.

d) both decrease heart rate and decrease pressure

Which of the following would increase heart rate?

a) increased sympathetic stimulation of SA node

b) decreased parasympathetic stimulation of nodal fibers

c) increased levels of epinephrine

d) faster depolarization of the pacemaker potential

e) All of the answers are correct.

e) All of the answers are correct

Stroke volume depends on

a) the pressure required to pump blood into the aorta.

b) the contractility of the ventricle.

c) venous return of blood to the heart.

d) end diastolic volume.

e) All of the answers are correct.

e) All of the answers are correct

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

a) pons.

b) higher centers.

c) medulla oblongata.

d) hypothalamus.

e) thalamus.

c) medulla oblongata