chapter 20

Question 1

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

/relaxation of both atria
/contraction of both atria
/contraction of the left atrium
/contraction of the right atrium

Answer 1

contraction of both atrium

Question 2

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

/end-systolic volume
/end-diastolic volume
/cardiac reserve
/stroke volume

Answer 2

End-Systolic volume

Question 3

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

 /end-diastolic volume
 /cardiac output
 /end-systolic volume
 /ejection fraction

Answer 3

Cardiac output

Question 4

The epicardium is also known as the __________.

 /endocardium
 /visceral pericardium
 /parietal pericardium
 /myocardium

Answer 4

visceral pericardium

Question 5

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

 /Cardiac muscle can't be tetanized.
 /Cardiac muscle contracts spontaneously.
 /Cardiac muscle lacks troponin.
 /Skeletal muscle is striated.

Answer 5

Cardiac muscle can’t be tetanized.

Question 6

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

 /right atrium
 /left atrium
 /pulmonary valve
 /pulmonary trunk

Answer 6

left atrium

Question 7

The papillary muscles function to __________.

 /prevent the AV valves from reversing into the atria
 /close the AV valves
 /eject blood from the ventricles
 /push blood from the atria into the ventricles

Answer 7

prevent the AV valves from reversing into the atria

Question 8

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

/ tricuspid
 /pulmonic
 /bicuspid
 /aortic

Answer 8

aortic

Question 9

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

/ right ventricle
 /right atrium
 /left atrium
 /left ventricle

Answer 9

right atrium

Question 10

Excess fluid in the ________ causes cardiac tamponade.

	 /visceral pericardium
	 /both atria
	 /left ventricle
	 /pericardial cavity
	 /apex of heart

Answer 10

pericardial cavity

Question 11

Intercalated discs serve to transfer ________ from cell to cell.

	/ electrical signals
	 /ionic currents
	 /the force of contraction
	 /action potentials
	 /All of the answers are correct.

Answer 11

All of the answers are correct.

Question 12

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

/ Cardiac muscle cells branch.
 /Cardiac muscle cells have a single, centered nucleus.
 /Skeletal muscle cells lack intercalated discs.
 /Cardiac muscle cells are smaller in size.
 /Cardiac muscle cells lack transverse tubules.

Answer 12

Cardiac muscle cells lack transverse tubules.

Question 13

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

	 /conus arteriosus.
	 /right ventricle.
	 /left atrium.
	 /right atrium.
	 /left ventricle.

Answer 13

right atrium.

Question 14

The cusps (leaflets) of atrioventricular valves attach directly to

	/ trabeculae carneae.
	 /papillary muscles.
	 /coronary sulci.
	 /interatrial septa.
	 /chordae tendineae.

Answer 14

chordae tendineae.

Question 15

The right ventricle pumps blood to the

	 /left atrium.
	 /left ventricle.
	 /right and left lungs.
	 /right atrium.
	 /aorta.

Answer 15

right and left lungs.

Question 16

The left ventricle pumps blood to the

	 /pulmonary circuit.
	 /aorta.
	 /right atrium.
	 /lungs.
	 /right ventricle.

Answer 16

aorta.

Question 17

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

	/ myocardial infarction.
	 /pulmonary embolism.
	 /coronary thrombosis.
	 /coronary spasm.
	 /angina pectoris.

Answer 17

coronary thrombosis.

Question 18

The first heart sound is heard when the

	/ semilunar valves close.
	 /blood enters the aorta.
	 /AV valves close.
	 /atria contract.
	 /AV valves open.

Answer 18

AV valves close.

Question 19

The pulmonary arteries carry blood to the

	/ brain.
	 /lungs.
	 /liver.
	 /intestines.
	 /heart.

Answer 19

lungs.

Question 20

The pulmonary veins carry blood to the

	/ heart.
	 /lungs.
	 /liver.
	 /brain.
	 /intestines.

Answer 20

heart.

Question 21

The foramen ovale in the fetal heart is located in the

	/ left ventricle.
	 /right atrium.
	 /right ventricle.
	 /interatrial septum.
	 /left atrium.

Answer 21

interatrial septum.

Question 22

Blood is supplied to the myocardium by

/ the coronary arteries.
 /the coronary sinus.
 /arteries that branch from the pulmonary arteries.
 /arteries that branch off the subclavian arteries.
 /contact with blood in the pumping chambers.

Answer 22

the coronary arteries.

Question 23

Heart rate is controlled by __________.

/ the right vagus nerve
 /sympathetic nerves in the cardiac plexus
 /both the right vagus and sympathetic nerves
 /the phrenic nerves

Answer 23

both the right vagus and sympathetic nerves

Question 24

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

/ PR segment
 /QRS complex
 /T wave
 /P wave

Answer 24

QRS complex

Question 25

The plateau phase of the ventricular action potential corresponds to the __________ phase of the electrocardiogram. / ST segment /T wave /PR interval

Answer 25

ST segment

Question 26

During the plateau phase of the cardiac action potential, which ion is entering the cardiac muscle cell? / potassium /calcium /hydrogen /sodium

Answer 26

calcium

Question 27

The conducting system in the heart begins in the __________. / SA node /AV node /AV bundle /Purkinje fibers

Answer 27

SA node

Question 28

The ________ deliver(s) blood to the myocardium. ``` / cardiac veins /superior vena cava /carotid arteries /coronary sinus /coronary arteries ```

Answer 28

coronary arteries

Question 29

Blood is supplied to the left atrium by the ``` / brachiocephalic artery. /pulmonary arteries. /right coronary artery. /left coronary artery. /phrenic arteries. ```

Answer 29

left coronary artery.

Question 30

The bicuspid or mitral valve is located / between the left atrium and left ventricle. /between the right atrium and right ventricle. /in the opening of the pulmonary trunk. /in the opening of the aorta. /where the venae cavae join the right atrium.

Answer 30

between the left atrium and left ventricle.

Question 31

The function of an atrium is to ``` / pump blood to the lungs. /pump blood into the systemic circuit. /pump blood to the ventricle. /collect blood then pump it to the ventricle. /collect blood. ```

Answer 31

collect blood then pump it to the ventricle.

Question 32

The normal pacemaker of the heart is located in ``` / the sinoatrial node. /the atrioventricular node. /the wall of the left ventricle. /the Purkinje fibers. /both the left and right ventricles. ```

Answer 32

the sinoatrial node.

Question 33

If the pacemaker cells in the SA node become more permeable to potassium ions, the ``` / heart rate will decrease and cells will hyperpolarize. /cells will hyperpolarize. /heart rate will increase. /cells will depolarize. /heart rate will decrease. ```

Answer 33

heart rate will decrease and cells will hyperpolarize.

Question 34

If the connection between the SA node and AV node becomes blocked, / the ventricles will beat more slowly. /the ventricles will beat faster. /the atria will contract more forcefully. /cardiac output will increase. /the ventricular beat will remain unchanged.

Answer 34

the ventricles will beat more slowly.

Question 35

Depolarization of the ventricles is represented on an electrocardiogram by the ``` / S wave. /P wave. /PR complex. /QRS complex. /T wave. ```

Answer 35

QRS complex.

Question 36

The one-way nature of the left AV valve prevents blood flow from _________. / the left ventricle to the left atrium /the aorta to the left ventricle /the left ventricle to the aorta /the left atrium to the left ventricle

Answer 36

the left ventricle to the left atrium

Question 37

The closing of the left AV valve occurs near the beginning of __________. / isovolumetric relaxation /ventricular diastole /atrial systole /ventricular systole

Answer 37

ventricular systole

Question 38

A heart murmur might be caused by ``` / aortic valve insufficiency. /swirling of blood in the ventricle. / mitral valve insufficiency. /pulmonic valve insufficiency. /All of the answers are correct. ```

Answer 38

All of the answers are correct.

Question 39

During ventricular systole, the / atria are contracting. /blood is entering the ventricles. /pressure in the aorta remains constant. /AV valves are closed. /pressure in the ventricles remains constant.

Answer 39

AV valves are closed.

Question 40

Which of the following will not increase heart rate? / increased levels of circulating epinephrine /faster rise of the pacemaker potential /increased parasympathetic stimulation of the SA node /increased sympathetic stimulation of the SA node

Answer 40

increased parasympathetic stimulation of the SA node

Question 41

Which of these changes will not increase cardiac output? / increased end-diastolic volume /increased stroke volume /increased heart rate /increased afterload

Answer 41

increased afterload

Question 42

An increase in the rate of action potentials from baroreceptors will trigger a reflex to / decrease in blood pressure. /increase in heart rate. / decrease in heart rate. /both decrease heart rate and decrease pressure. /both increase heart rate and increase pressure.

Answer 42

both decrease heart rate and decrease pressure.

Question 43

Which of the following would increase heart rate? / faster depolarization of the pacemaker potential /increased levels of epinephrine /increased sympathetic stimulation of SA node /decreased parasympathetic stimulation of nodal fibers /All of the answers are correct.

Answer 43

All of the answers are correct.

Question 44

Stroke volume depends on ``` / venous return of blood to the heart. /end diastolic volume. /the contractility of the ventricle. /the pressure required to pump blood into the aorta. /All of the answers are correct. ```

Answer 44

All of the answers are correct.

Question 45

Heart rate is controlled by neurons of the cardiovascular center located in the ``` / thalamus. /hypothalamus. /medulla oblongata. /higher centers. /pons. ```

Answer 45

medulla oblongata.