Cardiology

Which statement does not accurately describe the pericardium?

a. The pericardium is a double-walled membranous sac that encloses the heart.

b. It is made up of connective tissue and a surface layer of squamous cells.

c. The pericardium protects the heart against infection and inflammation from the

lungs and pleural space.

d. It contains pain and mechanoreceptors that can elicit reflex changes in blood

pressure and heart rate.

ANS: B

The pericardium is made up of a surface layer of mesothelium over a thin layer of

connective tissue. The remaining options accurately describe the pericardium.

Which cardiac chamber has the thinnest wall and why?

a. The right and left atria; they are low-pressure chambers that serve as storage units

and conduits for blood.

b. The right and left atria; they are not directly involved in the preload, contractility,

or afterload of the heart.

c. The left ventricle; the mean pressure of blood coming into this ventricle is from the

lung, which has a low pressure.

d. The right ventricle; it pumps blood into the pulmonary capillaries, which have a

lower pressure compared with the systemic circulation.

ANS: A

The two atria have the thinnest walls because they are low-pressure chambers that serve as

storage units and conduits for blood that is emptied into the ventricles. This selection is the

only option that correctly identifies which heart chambers have the thinnest walls and why

that helps cardiac function.

Regarding the heart's valves, what is a function of the papillary muscles?

a. The papillary muscles close the semilunar valve.

b. These muscles prevent backward expulsion of the atrioventricular valve.

c. They close the atrioventricular valve.

d. The papillary muscles open the semilunar valve.

ANS: B

The papillary muscles are extensions of the myocardium that pull the cusps together and

downward at the onset of ventricular contraction, thus preventing their backward

expulsion into the atria. This selection is the only option that correctly describes the

function of the papillary muscles.

The significance of the atrial kick is that it affects the contraction of the:

a. Right atria, which is necessary to open the tricuspid valve.

b. Right atria, which is necessary to increase the blood volume from the vena cava.

c. Left atria, which increases the blood volume into the ventricle.

d. Left atria, that is necessary to open the mitral valve.

ANS: C

Left atrial contraction, the atrial kick, provides a significant increase of blood to the left

ventricle.

Occlusion of the left anterior descending artery during a myocardial infarction would

interrupt blood supply to which structures?

a. Left and right ventricles and much of the interventricular septum

b. Left atrium and the lateral wall of the left ventricle

c. Upper right ventricle, right marginal branch, and right ventricle to the apex

d. Posterior interventricular sulcus and the smaller branches of both ventricles

ANS: A

The left anterior descending artery (LAD), also called the anterior interventricular artery,

delivers blood to portions of the left and right ventricles and much of the interventricular

septum. This selection is the only option affected by the occlusion described.

Occlusion of the circumflex artery during a myocardial infarction would interrupt blood

supply to which area?

a. Left and right ventricles and much of the interventricular septum

b. Posterior interventricular sulcus and the smaller branches of both ventricles

c. Upper right ventricle, right marginal branch, and right ventricle to the apex

d. Left atrium and the lateral wall of the left ventricle

ANS: D

The circumflex artery supplies blood to the left atrium and the lateral wall of the left

ventricle. The circumflex artery often branches to the posterior surfaces of the left atrium

and left ventricle. This selection is the only option affected by the occlusion described.

The coronary sinus empties into which cardiac structure?

a. Right atrium

b. Left atrium

c. Superior vena cava

d. Aorta

ANS: A

The cardiac veins empty only into the right atrium through another ostium, the opening of

a large vein called the coronary sinus.

During the cardiac cycle, which structure directly delivers action potential to the

ventricular myocardium?

a. Sinoatrial (SA) node

b. Atrioventricular (AV) node

c. Purkinje fibers

d. Bundle branches

ANS: C

Each cardiac action potential travels from the SA node to the AV node to the bundle of His

(AV bundle), through the bundle branches, and finally to the Purkinje fibers and the

ventricular myocardium, where the impulse is stopped. The refractory period of cells that

have just been polarized prevents the impulse from reversing its path. The refractory

period ensures that diastole (relaxation) will occur, thereby completing the cardiac cycle.

This selection is the only option that accurately describes the structure that delivers the

action potential directly to the myocardium.

What causes depolarization of a cardiac muscle cell to occur?

a. Decrease in the permeability of the cell membrane to potassium

b. Rapid movement of sodium into the cell

c. Decrease in the movement of sodium out of the cell

d. Rapid movement of calcium out of the cell

ANS: B

Phase 0 consists of depolarization, which lasts 1 to 2 milliseconds (ms) and represents

rapid sodium entry into the cell. This selection is the only option that accurately describes

the cause of cardiac muscle cell depolarization.

Which event occurs during phase 1 of the normal myocardial cell depolarization and

repolarization?

a. Repolarization when potassium moves out of the cells

b. Repolarization when sodium rapidly enters into the cells

c. Early repolarization when sodium slowly enters the cells

d. Early repolarization when calcium slowly enters the cells

ANS: D

Phase 1 is early repolarization and the only time during which calcium slowly enters the

cell.

Which phase of the normal myocardial cell depolarization and repolarization correlates

with diastole?

a. Phase 1

b. Phase 2

c. Phase 3

d. Phase 4

ANS: D

Potassium is moved out of the cell during phase 3, with a return to resting membrane

potential only in phase 4. The time between action potentials corresponds to diastole.

Which chamber of the heart endures the highest pressures?

a. Right atrium

c. Left ventricle

b. Left atrium

d. Right ventricle

ANS: C

Pressure is greatest in the systemic circulation, driven by the left ventricle.

What is the process that ensures mitral and tricuspid valve closure after the ventricles are

filled with blood?

a. Chordae tendineae relax, which allows the valves to close.

b. Increased pressure in the ventricles pushes the valves to close.

c. Trabeculae carneae contract, which pulls the valves closed.

d. Reduced pressure in the atria creates a negative pressure that pulls the valves

closed.

ANS: B

During ventricular relaxation, the two atrioventricular valves open and blood flows from

the higher pressure atria to the relaxed ventricles. With increasing ventricular pressure,

these valves close and prevent backflow into the atria as the ventricles contract. This

selection is the only option that correctly identifies the process that ensures closing of the

mitral and tricuspid valves.

During the cardiac cycle, why do the aortic and pulmonic valves close after the ventricles

relax?

a. Papillary muscles relax, which allows the valves to close.

b. Chordae tendineae contract, which pulls the valves closed.

c. Reduced pressure in the ventricles creates a negative pressure, which pulls the

valves closed.

d. Blood fills the cusps of the valves and causes the edges to merge, closing the

valves.

ANS: D

When the ventricles relax, blood fills the cusps and causes their free edges to meet in the

middle of the vessel, closing the valve and preventing any backflow. This selection is the

only option that accurately explains why the aortic and pulmonic valves close after the

ventricles contract.

Oxygenated blood flows through which vessel?

a. Superior vena cava

b. Pulmonary veins

c. Pulmonary artery

d. Coronary veins

ANS: B

Only the four pulmonary veins, two from the right lung and two from the left lung, carry

oxygenated blood from the lungs to the left side of the heart.

The coronary ostia are located in the:

a. Left ventricle

b. Aortic valve

c. Coronary sinus

d. Aorta

ANS: D

Coronary arteries receive blood through openings in the aorta, called the coronary ostia.

What is the ratio of coronary capillaries to cardiac muscle cells?

a. 1:1 (one capillary per one muscle cell)

b. 1:2 (one capillary per two muscle cells)

c. 1:4 (one capillary per four muscle cells)

d. 1:10 (one capillary per ten muscle cells)

ANS: A

The heart has an extensive capillary network, with approximately 3300 capillaries per

square millimeter (ca/mm2

) or approximately one capillary per one muscle cell (muscle

fiber).

In the normal electrocardiogram, what does the PR interval represent?

a. Atrial depolarization

b. Ventricular depolarization

c. Atrial activation to onset of ventricular activity

d. Electrical systole of the ventricles

ANS: C

The PR interval is a measure of time from the onset of atrial activation to the onset of

ventricular activation; it normally ranges from 0.12 to 0.20 second. The PR interval

represents the time necessary to travel from the sinus node through the atrium, the

atrioventricular (AV) node, and the His-Purkinje system to activate ventricular myocardial

cells. This selection is the only option that accurately describes the PR interval.

The cardiac electrical impulse normally begins spontaneously in the sinoatrial (SA) node

because it:

a. Has a superior location in the right atrium.

b. Is the only area of the heart capable of spontaneous depolarization.

c. Has rich sympathetic innervation via the vagus nerve.

d. Depolarizes more rapidly than other automatic cells of the heart.

ANS: D

The electrical impulse normally begins in the SA node because its cells depolarize more

rapidly than other automatic cells. This selection is the only option that accurately explains

why cardiac electrical impulses normally begin spontaneously in the SA node.

What period follows depolarization of the myocardium and represents a period during

which no new cardiac potential can be propagated?

a. Refractory

b. Hyperpolarization

c. Threshold

d. Sinoatrial (SA)

ANS: A

During the refractory period, no new cardiac action potential can be initiated by a

stimulus. This selection is the only option that accurately identifies the period described in

the question.

Which complex (wave) represents the sum of all ventricular muscle cell depolarizations?

a. PRS

b. QRS

c. QT interval

d. P

ANS: B

Only the QRS complex represents the sum of all ventricular muscle cell depolarizations.

What can shorten the conduction time of action potential through the atrioventricular (AV)

node?

a. Parasympathetic nervous system

b. Catecholamines

c. Vagal stimulation

d. Sinoatrial node (SA)

ANS: B

Catecholamines speed the heart rate, shorten the conduction time through the AV node,

and increase the rhythmicity of the AV pacemaker fibers. This selection is the only option

that can perform that function.

If the sinoatrial (SA) node fails, then at what rate (depolarizations per minute) can the

atrioventricular (AV) node depolarize?

a. 60 to 70

b. 40 to 60

c. 30 to 40

d. 10 to 20

ANS: B

If the SA node is damaged, then the AV node will become the heart's pacemaker at a rate

of approximately 40 to 60 spontaneous depolarizations per minute.

What is the effect of epinephrine on E3 receptors on the heart?

a. Decreases coronary blood flow.

b. Supplements the effects of both E1 and E2 receptors.

c. Increases the strength of myocardial contraction.

d. Prevents overstimulation of the heart by the sympathetic nervous system.

ANS: D

E3 receptors are found in the myocardium and coronary vessels. In the heart, stimulation of

these receptors opposes the effects of E1- and E2-receptor stimulation and negative

inotropic effect. Thus E3 receptors may provide a safety mechanism that decreases

myocardial contractility to prevent overstimulation of the heart by the sympathetic nervous

system. This selection is the only option that accurately describes the effect of epinephrine

on E2 receptors on the heart.

Where in the heart are the receptors for neurotransmitters located?

a. Semilunar and atrioventricular (AV) valves

b. Endocardium and sinoatrial (SA) node

c. Myocardium and coronary vessels

d. Epicardium and AV node

ANS: C

Sympathetic neural stimulation of the myocardium and coronary vessels depends on the

presence of adrenergic receptors, which specifically bind with neurotransmitters of the

sympathetic nervous system. The E1 receptors are found mostly in the heart, specifically

the conduction system (AV and SA nodes, Purkinje fibers) and the atrial and ventricular

myocardium, whereas the E2 receptors are found in the heart and also on vascular smooth

muscle. E3 receptors are also found in the myocardium and coronary vessels. This

selection is the only option that accurately identifies the location of the receptors for

neurotransmitters.

What enables electrical impulses to travel in a continuous cell-to-cell fashion in

myocardial cells?

a. Sarcolemma sclerotic plaques

b. Intercalated disks

c. Trabeculae carneae

d. Bachmann bundles

ANS: B

Only intercalated disks, thickened portions of the sarcolemma, enable electrical impulses

to spread quickly in a continuous cell-to-cell (syncytial) fashion.

Within a physiologic range, what does an increase in left ventricular end-diastolic volume

(preload) result in?

a. Increase in force of contraction

b. Decrease in refractory time

c. Increase in afterload

d. Decrease in repolarization

ANS: A

This concept is expressed in the Frank-Starling law; the cardiac muscle, like other

muscles, increases its strength of contraction when it is stretched. This selection is the only

option that accurately describes the result of an increase in preload.

As stated in the Frank-Starling law, a direct relationship exists between the _____ of the

blood in the heart at the end of diastole and the _____ of contraction during the next

systole.

a. Pressure; force

b. Volume; strength

c. Viscosity; force

d. Viscosity; strength

ANS: B

As stated in the Frank-Starling law, the volume of blood in the heart at the end of diastole

(the length of its muscle fibers) is directly related to the force (strength) of contraction

during the next systole. This selection is the only option that accurately describes the

relationship associated with the Frank-Starling law.

Pressure in the left ventricle must exceed pressure in which structure before the left

ventricle can eject blood?

a. Superior vena cava

b. Aorta

c. Inferior vena cava

d. Pulmonary veins

ANS: B

Pressure in the ventricle must exceed aortic pressure before blood can be pumped out

during systole. The aorta is the only structure in which pressure must be less than the

amount of blood in the left ventricle for ejection to occur.

Continuous increases in left ventricular filing pressures result in which disorder?

a. Mitral regurgitation

b. Mitral stenosis

c. Pulmonary edema

d. Jugular vein distention

ANS: C

Pressure changes are important because increased left ventricular filling pressures back up

into the pulmonary circulation, where they force plasma out through vessel walls, causing

fluid to accumulate in lung tissues (pulmonary edema). This selection is the only option

that accurately identifies the disorder described in the question.

When the volume of blood in the ventricle at the end of diastole increases, the force of the

myocardial contraction during the next systole will also increase, which is an example of

which law or theory about the heart?

a. Laplace's law

b. Poiseuille law

c. Cross-bridge theory

d. Frank-Starling law

ANS: D

This concept is expressed only in the Frank-Starling law; the cardiac muscle, like other

muscles, increases its strength of contraction when it is stretched.

The resting heart rate in a healthy person is primarily under the control of which nervous

system?

a. Sympathetic

b. Parasympathetic

c. Somatic

d. Spinal

ANS: B

The resting heart rate in healthy individuals is primarily under the control of

parasympathetic stimulation. This selection is the only option that accurately identifies the

nervous system responsible for the healthy resting heart.

The Bainbridge reflex is thought to be initiated by sensory neurons in which cardiac

location?

a. Atria

b. Aorta

c. Sinoatrial (SA) node

d. Ventricles

ANS: A

The Bainbridge reflex causes changes in the heart rate after intravenous infusions of blood

or other fluid. The changes in heart rate are thought to be caused by a reflex mediated by

volume receptors found only in the atria that are innervated by the vagus nerve.

After the baroreceptor reflex is stimulated, the resulting impulse is transmitted from the

carotid artery by which sequence of events?

a. Vagus nerve to the medulla to increase parasympathetic activity and to decrease

sympathetic activity

b. Glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase

sympathetic activity and to decrease parasympathetic activity

c. Glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase

parasympathetic activity and to decrease sympathetic activity

d. Glossopharyngeal cranial nerve through the vagus nerve to the hypothalamus to

increase parasympathetic activity and to decrease sympathetic activity

ANS: C

Neural impulses are transmitted over the glossopharyngeal nerve (ninth cranial nerve)

from the carotid artery and through the vagus nerve from the aorta to the cardiovascular

control centers in the medulla. These centers initiate an increase in parasympathetic

activity and a decrease in sympathetic activity, causing blood vessels to dilate and the

heart rate to decrease. This selection is the only option that accurately describes the correct

sequence of events asked for in the question.

Reflex control of total cardiac output and total peripheral resistance is controlled by what

mechanism?

a. Parasympathetic stimulation of the heart, arterioles, and veins

b. Sympathetic stimulation of the heart, arterioles, and veins

c. Autonomic control of the heart only

d. Somatic control of the heart, arterioles, and veins

ANS: B

Reflex control of total cardiac output and peripheral resistance includes (1) sympathetic

stimulation of the heart, arterioles, and veins; and (2) parasympathetic stimulation of the

heart only. Neither autonomic nor somatic controls are involved in this process.

What is the most important negative inotropic agent?

a. Norepinephrine

b. Epinephrine

c. Acetylcholine

d. Dopamine

ANS: C

Chemicals affecting contractility are called inotropic agents. The most important negative

inotropic agent is acetylcholine released from the vagus nerve. The most important

positive inotropic agents produced by the body are norepinephrine released from the

sympathetic nerves that supply the heart and epinephrine released by the adrenal cortex.

Other positive inotropes include thyroid hormone and dopamine. Many medications have

positive or negative inotropic properties that can have profound effects on cardiac

function. This selection is the only option that accurately identifies the regulation that is

involved in the described process.

The right lymphatic duct drains into which structure?

a. Right subclavian artery

b. Right atrium

c. Right subclavian vein

d. Superior vena cava

ANS: C

The right lymphatic duct drains lymph only into the right subclavian vein.

Where is the major cardiovascular center in the central nervous system?

a. Frontal lobe

b. Thalamus

c. Brainstem

d. Hypothalamus

ANS: C

The major cardiovascular control center is in the brainstem in the medulla with secondary

areas in the hypothalamus, the cerebral cortex, the thalamus, and the complex networks of

exciting or inhibiting interneurons (connecting neurons) throughout the brain. This

selection is the only option that accurately identifies the cardiovascular control center.

What is an expected change in the cardiovascular system that occurs with aging?

a. Arterial stiffening

b. Decreased left ventricular wall tension

c. Decreased aortic wall thickness

d. Arteriosclerosis

ANS: A

Arterial stiffening occurs with aging even in the absence of clinical hypertension. Aging is

not responsible for the other conditions.

What is the major determinant of the resistance that blood encounters as it flows through

the systemic circulation?

a. Volume of blood in the systemic circulation

b. Muscle layer of the metarterioles

c. Muscle layer of the arterioles

d. Force of ventricular contraction

ANS: C

Of the options available, only the thick, smooth muscle layer of the arterioles is a major

determinant of the resistance blood encounters as it flows through the systemic circulation.

Which function of the cardiovascular system is often affected by ischemia?

a. Cardiac output (CO)

b. Stroke volume (SV)

c. Heart rate (HR)

d. Cardiac index (CI)

ANS: C

Common causes of an abnormal heart rate include ischemia, electrolyte imbalance, and

drug toxicity. The other options are related to vascular resistance changes.

What physical sign is the result of turbulent blood flow through a vessel?

a. Increased blood pressure during periods of stress

b. Bounding pulse felt on palpation

c. Cyanosis observed on excretion

d. Murmur heard on auscultation

ANS: D

Where flow is obstructed, the vessel turns or blood flows over rough surfaces. The flow

becomes turbulent with whorls or eddy currents that produce noise, causing a murmur to

be heard on auscultation, such as occurs during blood pressure measurement with a

sphygomanometer. This selection is the only option that accurately identifies the physical

sign of turbulent vascular blood flow.

What is the major effect of a calcium channel blocker such as verapamil on cardiac

contractions?

a. Increases the rate of cardiac contractions.

b. Decreases the strength of cardiac contractions.

c. Stabilizes the rhythm of cardiac contractions.

d. Stabilizes the vasodilation during cardiac contractions.

ANS: B

The L-type, or long-lasting, channels are the predominant type of calcium channels and are

the channels blocked by calcium channel-blocking drugs (verapamil, nifedipine,

diltiazem). The major effect of these medications is to decrease the strength of cardiac

contraction. This selection is the only option that accurately identifies the effect of a

calcium channel blocker on the cardiac contractions.

An early diastole peak caused by filling of the atrium from peripheral veins is identified by

which intracardiac pressure?

a. A wave

b. V wave

c. C wave

d. X descent

ANS: B

The V wave is an early diastolic peak caused by the filling of the atrium from the

peripheral veins. This event is not identified by any of the other options.

Which intracardiac pressure is generated by the atrial contraction?

a. A wave

b. C wave

c. Y descent

d. X descent

ANS: A

Atrial pressure curves are made up of only the A wave, which is generated by atrial

contraction.

Which intracardiac pressure is produced because of the descent of the tricuspid valve ring

and by the ejection of blood from both ventricles?

a. V wave

b. C wave

c. Y descent

d. X descent

ANS: D

The X descent follows an A wave and is produced because of the descent of the tricuspid

valve ring and by the ejection of blood from both ventricles.

Which statements are true concerning the method in which substances pass between

capillaries and the interstitial fluid? (Select all that apply.)

a. Substances pass through junctions between endothelial cells.

b. Substances pass through pores or oval windows (fenestrations).

c. Substances pass between vesicles by active transport across the endothelial cell

membrane.

d. Substances pass across the endothelial cell membrane by osmosis.

e. Substances pass through endothelial cell membranes by diffusion.

ANS: A, B, C, E

Substances pass between the capillary lumen and the interstitial fluid in several ways: (1)

through junctions between endothelial cells, (2) through fenestrations in endothelial cells,

(3) in vesicles moved by active transport across the endothelial cell membrane, or (4) by

diffusion through the endothelial cell membrane.

Poiseuille law

Poiseuille law for resistance to fluid flow through a tube takes into account the length of the

tube, the viscosity of the fluid, and the radius of the tube's lumen.

Cross-bridge theory

With the attachment of actin to myosin at the cross-bridge, the myosin head molecule

undergoes a position change, exerting traction on the rest of the myosin bridge, causing the thin

filaments to slide past the thick filaments. During contraction, each cross-bridge undergoes cycles

of attachment, movement, and dissociation from the thin filaments.

Frank-Starling law

states that the cardiac muscle, like other muscles, increases its

strength of contraction when it is stretched.

Laplace's law

wall tension is directly related to the product of intraventricular pressure

and internal radius and inversely to the wall thickness.

Bainbridge reflex

causes changes in the heart rate after intravenous infusions of blood

or other fluid.

What is the initiating event that leads to the development of atherosclerosis?

a. Release of the inflammatory cytokines

b. Macrophages adhere to vessel walls.

c. Injury to the endothelial cells that line the artery walls

d. Release of the platelet-deprived growth factor

ANS: C

Atherosclerosis begins with an injury to the endothelial cells that line the arterial walls.

Possible causes of endothelial injury include the common risk factors for atherosclerosis,

such as smoking, hypertension, diabetes, increased levels of low-density lipoprotein

(LDL), decreased levels of high-density lipoprotein (HDL), and autoimmunity. The

remaining options occur only after the endothelial cells are injured.

What is the effect of oxidized low-density lipoproteins (LDLs) in atherosclerosis?

a. LDLs cause smooth muscle proliferation.

b. LDLs cause regression of atherosclerotic plaques.

c. LDLs increase levels of inflammatory cytokines.

d. LDLs direct macrophages to the site in the endothelium.

ANS: A

Oxidized LDLs are toxic to endothelial cells, cause smooth muscle proliferation, and

activate further immune and inflammatory responses. This selection is the only option that

accurately identifies the effects of LDLs.

Which inflammatory cytokines are released when endothelial cells are injured?

a. Granulocyte-macrophage colony-stimulating factor (GM-CSF)

b. Interferon-beta (IFN-E), interleukin 6 (IL-6), and granulocyte colony-stimulating

factor (G-CSF)

c. Tumor necrosis factor-alpha (TNF-D), interferon-gamma (IFN-J), and interleukin

1 (IL-1)

d. Interferon-alpha (IFN-D), interleukin-12 (IL-12), and macrophage

colony-stimulating factor (M-CSF)

ANS: C

Numerous inflammatory cytokines are released, including TNF-D, IFN-J, IL-1, toxic

oxygen radicals, and heat shock proteins. This selection is the only option that accurately

identifies which inflammatory cytokines are associated with endothelial cell injury.

When endothelia cells are injured, what alteration contributes to atherosclerosis?

a. The release of toxic oxygen radicals that oxidize low-density lipoproteins (LDLs).

b. Cells are unable to make the normal amount of vasodilating cytokines.

c. Cells produce an increased amount of antithrombotic cytokines.

d. Cells develop a hypersensitivity to homocysteine and lipids.

ANS: B

Injured endothelial cells become inflamed and cannot make normal amounts of

antithrombotic and vasodilating cytokines. This selection is the only option that accurately

identifies the factor that contributes to atherosclerosis.

Which factor is responsible for the hypertrophy of the myocardium associated with

hypertension?

a. Increased norepinephrine

b. Adducin

c. Angiotensin II

d. Insulin resistance

ANS: C

Of the available options, only angiotensin II is responsible for the hypertrophy of the

myocardium and much of the renal damage associated with hypertension.

What pathologic change occurs to the kidney's glomeruli as a result of hypertension?

a. Compression of the renal tubules

b. Ischemia of the tubule

c. Increased pressure from within the tubule

d. Obstruction of the renal tubule

ANS: B

In the kidney, vasoconstriction and resultant decreased renal perfusion cause tubular

ischemia and preglomerular arteriopathy. This selection is the only option that accurately

identifies the pathologic change to the kidney that occurs as a result of hypertension.

What effect does atherosclerosis have on the development of an aneurysm?

a. Atherosclerosis causes ischemia of the intima.

b. It increases nitric oxide.

c. Atherosclerosis erodes the vessel wall.

d. It obstructs the vessel.

ANS: C

Atherosclerosis is a common cause of aneurysms because plaque formation erodes the

vessel wall. This selection is the only option that accurately identifies the effect that

atherosclerosis has on aneurysm development.

Regarding the endothelium, what is the difference between healthy vessel walls and those

that promote clot formation?

a. Inflammation and roughening of the endothelium of the artery are present.

b. Hypertrophy and vasoconstriction of the endothelium of the artery are present.

c. Excessive clot formation and lipid accumulation in the endothelium of the artery

are present.

d. Evidence of age-related changes that weaken the endothelium of the artery are

present.

ANS: A

Invasion of the tunica intima by an infectious agent also roughens the normally smooth

lining of the artery, causing platelets to adhere readily. This selection is the only option

that accurately describes the mechanism that supports abnormal clot formation.

What is the usual source of pulmonary emboli?

a. Deep venous thrombosis

b. Endocarditis

c. Valvular disease

d. Left heart failure

ANS: A

Pulmonary emboli originate in the venous circulation (mostly from the deep veins of the

legs) or in the right heart. This selection is the only option that accurately identifies the

usual source of pulmonary emboli.

Which factor can trigger an immune response in the bloodstream that may result in an

embolus?

a. Amniotic fluid

b. Fat

c. Bacteria

d. Air

ANS: A

Of the options available, only amniotic fluid displaces blood, thereby reducing oxygen,

nutrients, and waste exchange; however, it also introduces antigens, cells, and protein

aggregates that trigger inflammation, coagulation, and the immune response in the

bloodstream.

Which statement best describes thromboangiitis obliterans (Buerger disease)?

a. Inflammatory disorder of small- and medium-size arteries in the feet and

sometimes in the hands

b. Vasospastic disorder of the small arteries and arterioles of the fingers and, less

commonly, of the toes

c. Autoimmune disorder of the large arteries and veins of the upper and lower

extremities

d. Neoplastic disorder of the lining of the arteries and veins of the upper extremities

ANS: A

Buerger disease is an inflammatory disease of the peripheral arteries. Inflammation,

thrombus formation, and vasospasm can eventually occlude and obliterate portions of

small- and medium-size arteries. The digital, tibial, and plantar arteries of the feet and the

digital, palmar, and ulnar arteries of the hands are typically affected. This selection is the

only option that accurately describes Buerger disease.

Which statement best describes Raynaud disease?

a. Inflammatory disorder of small- and medium-size arteries in the feet and

sometimes in the hands

b. Neoplastic disorder of the lining of the arteries and veins of the upper extremities

c. Vasospastic disorder of the small arteries and arterioles of the fingers and, less

commonly, of the toes

d. Autoimmune disorder of the large arteries and veins of the upper and lower

extremities

ANS: C

Attacks of vasospasm in the small arteries and arterioles of the fingers and, less

commonly, of the toes characterize Raynaud phenomenon and Raynaud disease and is the

only option that accurately describes this disease.

What change in a vein supports the development of varicose veins?

a. Increase in osmotic pressure

b. Damage to the valves in veins

c. Damage to the venous endothelium

d. Increase in hydrostatic pressure

ANS: B

If a valve is damaged, permitting backflow, then a section of the vein is subjected to the

pressure exerted by a larger volume of blood under the influence of gravity. The vein

swells as it becomes engorged, and the surrounding tissue becomes edematous because

increased hydrostatic pressure pushes plasma through the stretched vessel wall. This

selection is the only option that accurately describes the development of varicose veins.

Superior vena cava syndrome is a result of a progressive increase of which process?

a. Inflammation

b. Occlusion

c. Distention

d. Sclerosis

ANS: B

Superior vena cava syndrome (SVCS) is a progressive occlusion of the superior vena cava

(SVC) that leads to venous distention in the upper extremities and head. The remaining

options are not associated with this disorder.

What term is used to identify when a cell is temporarily deprived of blood supply?

a. Infarction

b. Ischemia

c. Necrosis

d. Inflammation

ANS: B

Coronary artery disease (CAD) can diminish the myocardial blood supply until deprivation

impairs myocardial metabolism enough to cause ischemia, a local state in which the cells

are temporarily deprived of blood supply. This term is the only option that is used to

identify a temporarily deprived blood supply.

The risk of developing coronary artery disease is increased up to threefold by which

factor?

a. Diabetes mellitus

b. Hypertension

c. Obesity

d. High alcohol consumption

ANS: B

Hypertension is the only factor responsible for a twofold-to-threefold increased risk of

atherosclerotic cardiovascular disease.

Which risk factor is associated with coronary artery disease (CAD) because of its

relationship with the alteration of hepatic lipoprotein?

a. Diabetes mellitus

b. Hypertension

c. Obesity

d. High alcohol consumption

ANS: A

Of the available options, only diabetes mellitus is associated with CAD because of the

resulting alteration of hepatic lipoprotein synthesis; it increases triglyceride levels and is

involved in low-density lipoprotein oxidation.

Nicotine increases atherosclerosis by the release of which neurotransmitter?

a. Histamine

b. Nitric oxide

c. Angiotensin II

d. Epinephrine

ANS: D

Nicotine stimulates the release of catecholamines (e.g., epinephrine, norepinephrine),

which increases the heart rate and causes peripheral vascular constriction. As a result,

blood pressure increases, as do both cardiac workload and oxygen demand. None of the

other options are associated with this mechanism.

Which substance is manufactured by the liver and primarily contains cholesterol and

protein?

a. Very low-density lipoproteins (VLDLs)

b. Low-density lipoproteins (LDLs)

c. High-density lipoproteins (HDLs)

d. Triglycerides

ANS: B

A series of chemical reactions in the liver results in the production of several lipoproteins

that vary in density and function. These include VLDLs, primarily triglycerides and

protein; LDLs, mostly cholesterol and protein; and HDLs, mainly phospholipids and

protein. LDLs are the only lipoproteins that are manufactured by the liver and primarily

contain cholesterol and protein.

Which elevated value may be protective of the development of atherosclerosis?

a. Very low-density lipoproteins (VLDLs)

b. Low-density lipoproteins (LDLs)

c. High-density lipoproteins (HDLs

d. Triglycerides

ANS: C

Low levels of HDL cholesterol are also a strong indicator of coronary risk, whereas high

levels of HDLs may be more protective for the development of atherosclerosis than low

levels of LDLs. Neither VLDLs nor elevated triglycerides are associated with a protective

mechanism.

Which laboratory test is an indirect measure of atherosclerotic plaque?

a. Homocysteine

b. Low-density lipoprotein (LDL)

c. Erythrocyte sedimentation rate (ESR)

d. C-reactive protein (CRP)

ANS: D

Highly sensitive CRP (hs-CRP) is an acute phase reactant or protein mostly synthesized in

the liver and, of the available options, is an indirect measure of atherosclerotic

plaque-related inflammation.

Cardiac cells can withstand ischemic conditions and still return to a viable state for how

many minutes?

a. 10

b. 15

c. 20

d. 25

ANS: C

Cardiac cells remain viable for approximately 20 minutes under ischemic conditions. If

blood flow is restored, then aerobic metabolism resumes, contractility is restored, and

cellular repair begins. If the coronary artery occlusion persists beyond 20 minutes, then

myocardial infarction (MI) occurs.

Which form of angina occurs most often during sleep as a result of vasospasms of one or

more coronary arteries?

a. Unstable

b. Stable

c. Silent

d. Prinzmetal

ANS: D

Of the options available, only Prinzmetal angina (also called variant angina) is chest pain

attributable to transient ischemia of the myocardium that occurs unpredictably and almost

exclusively at rest.

When is the scar tissue that is formed after a myocardial infarction (MI) most vulnerable to

injury?

a. Between 5 and 9 days

b. Between 10 and 14 days

c. Between 15 and 20 days

d. Between 20 and 30 days

ANS: B

During the recovery period (10 to 14 days after infarction), individuals feel more capable

of increasing activities and thus may stress the newly formed scar tissue. After 6 weeks,

the necrotic area is completely replaced by scar tissue, which is strong but unable to

contract and relax like healthy myocardial tissue.

An individual who is demonstrating elevated levels of troponin, creatine

kinase-isoenzyme MB (CK-MB), and lactic dehydrogenase (LDH) is exhibiting indicators

associated with which condition?

a. Myocardial ischemia

b. Hypertension

c. Myocardial infarction (MI)

d. Coronary artery disease (CAD)

ANS: C

Cardiac troponins (troponin I and troponin T) are the most specific indicators of MI. Other

biomarkers released by myocardial cells include CK-MB and LDH, but they are not

associated with the other options.

What is the expected electrocardiogram (ECG) pattern when a thrombus in a coronary

artery permanently lodges in the vessel and the infarction extends through the myocardium

from the endocardium to the epicardium?

a. Prolonged QT interval

b. ST elevation myocardial infarction (STEMI)

c. ST depression myocardial infarction (STDMI)

d. Non-ST elevation myocardial infarction (non-STEMI)

ANS: B

Individuals with this pattern on an ECG usually have significant elevations in the ST

segments and are categorized as having STEMI. The other options are not associated with

the described pathologic condition.

How does angiotensin II increase the workload of the heart after a myocardial infarction

(MI)?

a. By increasing the peripheral vasoconstriction

b. By causing dysrhythmias as a result of hyperkalemia

c. By reducing the contractility of the myocardium

d. By stimulating the sympathetic nervous system

ANS: A

Angiotensin II is released during myocardial ischemia and contributes to the pathogenesis

of a myocardial infarction (MI) in several ways. First, it results in the systemic effects of

peripheral vasoconstriction and fluid retention. These homeostatic responses are

counterproductive in that they increase myocardial work and thus exacerbate the effects of

the loss of myocyte contractility. Angiotensin II is also locally released, where it is a

growth factor for vascular smooth muscle cells, myocytes, and cardiac fibroblasts;

promotes catecholamine release; and causes coronary artery spasm. This selection is the

only option that accurately describes how angiotensin II increases workload after a MI.

The pulsus paradoxus that occurs as a result of pericardial effusion is caused by a

dysfunction in which mechanism?

a. Diastolic filling pressures of the right ventricle and reduction of blood volume in

both ventricles

b. Blood ejected from the right atrium and reduction of blood volume in the right

ventricle

c. Blood ejected from the left atrium and reduction of blood volume in the left

ventricle

d. Diastolic filling pressures of the left ventricle and reduction of blood volume in all

four heart chambers.

ANS: D

Pulsus paradoxus means that the arterial blood pressure during expiration exceeds arterial

pressure during inspiration by more than 10 mm Hg. This clinical finding reflects

impairment of diastolic filling of the left ventricle plus a reduction of blood volume within

all four cardiac chambers. This selection is the only option that accurately describes the

mechanism.

A patient reports sudden onset of severe chest pain that radiates to the back and worsens

with respiratory movement and when lying down. These clinical manifestations describe:

a. Myocardial infarction (MI)

b. Pericardial effusion

c. Restrictive pericarditis

d. Acute pericarditis

ANS: D

Most individuals with acute pericarditis describe several days of fever, myalgias, and

malaise, followed by the sudden onset of severe chest pain that worsens with respiratory

movements and with lying down. Although the pain may radiate to the back, it is generally

felt in the anterior chest and may be initially confused with the pain of an acute MI.

Individuals with acute pericarditis also may report dysphagia, restlessness, irritability,

anxiety, and weakness. This selection is the only option with these symptoms.

Ventricular dilation and grossly impaired systolic function, leading to dilated heart failure,

characterize which form of cardiomyopathy?

a. Congestive

b. Hypertrophic

c. Septal

d. Dystrophic

ANS: A

Only dilated cardiomyopathy (congestive cardiomyopathy) is characterized by ventricular

dilation and grossly impaired systolic function, leading to dilated heart failure.

A disproportionate thickening of the interventricular septum is the hallmark of which form

of cardiomyopathy?

a. Dystrophic

b. Hypertrophic

c. Restrictive

d. Dilated

ANS: B

Only hypertrophic cardiomyopathy is characterized by a thickening of the septal wall,

which may cause outflow obstruction to the left ventricle outflow tract.

Amyloidosis, hemochromatosis, or glycogen storage disease usually causes which form of

cardiomyopathy?

a. Infiltrative

b. Restrictive

c. Septal

d. Hypertrophic

ANS: B

Restrictive cardiomyopathy may occur idiopathically or as a cardiac manifestation of

systemic diseases, such as scleroderma, amyloidosis, sarcoidosis, lymphoma, and

hemochromatosis, or a number of inherited storage diseases. This characterization is not

true of the other forms of cardiomyopathy.

Which condition is a cause of acquired aortic regurgitation?

a. Congenital malformation

b. Cardiac failure

c. Rheumatic fever

d. Coronary artery disease (CAD)

ANS: C

Rheumatic heart disease, bacterial endocarditis, syphilis, hypertension, connective tissue

disorders (e.g., Marfan syndrome, ankylosing spondylitis), appetite suppressing

medications, trauma, or atherosclerosis can cause acquired aortic regurgitation. This

selection is the only available option that is known to cause acquired aortic regurgitation.

Which predominantly female valvular disorder is thought to have an autosomal dominant

inheritance pattern, as well as being associated with connective tissue disease?

a. Mitral valve prolapse

b. Tricuspid stenosis

c. Tricuspid valve prolapse

d. Aortic insufficiency

ANS: A

Mitral valve prolapse tends to be most prevalent in young women. Studies suggest an

autosomal dominant and X-linked inheritance pattern. Because mitral valve prolapse often

is associated with other inherited connective tissue disorders (e.g., Marfan syndrome,

Ehlers-Danlos syndrome, osteogenesis imperfecta), it is thought to result from a genetic or

environmental disruption of valvular development during the fifth or sixth week of

gestation. This provided history is not associated with any of the other options.

Which disorder causes a transitory truncal rash that is nonpruritic and pink with

erythematous macules that may fade in the center, making them appear as a ringworm?

a. Fat emboli

b. Rheumatic fever

c. Bacterial endocarditis

d. Myocarditis of acquired immunodeficiency syndrome

ANS: B

Erythema marginatum is a distinctive truncal rash that often accompanies acute rheumatic

fever. It consists of nonpruritic, pink erythematous macules that never occur on the face or

hands. This presentation is not associated with any of the other options.

What is the most common cause of infective endocarditis?

a. Virus

b. Fungus

c. Bacterium

d. Rickettsiae

ANS: C

Infective endocarditis is a general term used to describe infection and inflammation of the

endocardium—especially the cardiac valves. Bacteria are the most common cause of

infective endocarditis, especially streptococci, staphylococci, or enterococci.

What is the most common cardiac disorder associated with acquired immunodeficiency

syndrome (AIDS)

a. Cardiomyopathy

b. Myocarditis

c. Left heart failure

d. Heart block

ANS: C

Pericardial effusion and left heart failure are the most common complications of human

immunodeficiency virus (HIV) infection. Other conditions include cardiomyopathy,

myocarditis, tuberculous pericarditis, infective and nonbacterial endocarditis, heart block,

pulmonary hypertension, and nonantiretroviral drug-related cardiotoxicity.

A patient is diagnosed with pulmonary disease and elevated pulmonary vascular

resistance. Which form of heart failure may result from pulmonary disease and elevated

pulmonary vascular resistance?

a. Right heart failure

b. Left heart failure

c. Low-output failure

d. High-output failure

ANS: A

Right heart failure is defined as the inability of the right ventricle to provide adequate

blood flow into the pulmonary circulation at a normal central venous pressure. This

condition is often a result of pulmonary disease and the resulting elevated pulmonary

vascular resistance.

What cardiac pathologic condition contributes to ventricular remodeling?

a. Left ventricular hypertrophy

b. Right ventricular failure

c. Myocardial ischemia

d. Contractile dysfunction

ANS: C

Of the options available, myocardial ischemia contributes to inflammatory, immune, and

neurohumoral changes that mediate a process called ventricular remodeling.

In systolic heart failure, what effect does the renin-angiotensin-aldosterone system

(RAAS) have on stroke volume?

a. Increases preload and decreases afterload.

b. Increases preload and increases afterload.

c. Decreases preload and increases afterload.

d. Decreases preload and decreases afterload.

ANS: B

Activation of the RAAS not only causes an increase in preload and afterload, but it also

causes direct toxicity to the myocardium. This selection is the only option that accurately

identifies the effect that the RAAS has on stroke volume in this situation.

What is the cause of the dyspnea resulting from a thoracic aneurysm?

a. Pressure on surrounding organs

b. Poor oxygenation

c. Formation of atherosclerotic lesions

d. Impaired blood flow

ANS: A

Clinical manifestations depend on the location of the aneurysm. Pressure of a thoracic

aneurysm on surrounding organs cause symptoms of dysphagia (difficulty in swallowing)

and dyspnea (breathlessness). This selection is the only option that accurately describes the

cause of dyspnea resulting from a thoracic aneurysm.

Which statement is true concerning the cells' ability to synthesize cholesterol?

a. Cell production of cholesterol is affected by the aging process.

b. Cells produce cholesterol only when dietary fat intake is low.

c. Most body cells are capable of producing cholesterol.

d. Most cholesterol produced by the cells is converted to the low-density form.

ANS: C

Although cholesterol can easily be obtained from dietary fat intake, most body cells can

also manufacture cholesterol. This selection is the only option that accurately describes the

cellular role in cholesterol synthesis.

What is the trigger for angina pectoris?

a. Atherosclerotic lesions

b. Hyperlipidemia

c. Myocardial necrosis

d. Myocardial ischemia

ANS: D

Angina pectoris is chest pain caused by myocardial ischemia. None of the other options

are considered triggers for angina pectoris.

Individuals being effectively managed for type 2 diabetes mellitus often experience a

healthy decline in blood pressure as a result of what intervention?

a. Managed carbohydrate intake

b. Appropriate exercise

c. Insulin-sensitivity medication therapy

d. Introduction of minimal doses of insulin

ANS: C

Many people with type 2 diabetes mellitus, who are treated with drugs that increase insulin

sensitivity, experience a decline in their blood pressure without taking antihypertensive

drugs. Although the other medications may be included in the management plan, the other

options are not associated with a decrease in hypertension.

Which statements are true regarding fatty streaks? (Select all that apply.)

a. Fatty streaks progressively damage vessel walls.

b. Fatty streaks are capable of producing toxic oxygen radials.

c. When present, inflammatory changes occur to the vessel walls.

d. Oxidized low-density lipoproteins (LDLs) are involved in their formation.

e. Fatty streaks are formed by killer T cells filled with oxidized LDLs.

ANS: A, B, C, D

The oxidized LDLs penetrate the intima of the arterial wall and are engulfed by

macrophages. Macrophages filled with oxidized LDLs are called foam. Once these

lipid-laden foam cells accumulate in significant amounts, they form a lesion called a fatty

streak. Once formed, fatty streaks produce more toxic oxygen radicals and cause

immunologic and inflammatory changes, resulting in progressive damage to the vessel

wall.

What factors contribute to the development of orthostatic hypotension? (Select all that

apply.)

a. Altered body chemistry

b. Drug action of certain antihypertensive agents

c. Prolonged immobility

d. Effects of aging on postural reflexes

e. Any condition that produces volume overload

ANS: A, B, C, D

Orthostatic hypotension may be acute or chronic. Acute orthostatic hypotension

(temporary type) may result from (1) altered body chemistry, (2) drug action (e.g.,

antihypertensives, antidepressants), (3) prolonged immobility caused by illness, (4)

starvation, (5) physical exhaustion, (6) any condition that produces volume depletion (e.g.,

massive diuresis, potassium or sodium depletion), and (7) venous pooling (e.g., pregnancy,

extensive varicosities of the lower extremities). Older adults are susceptible to this type of

orthostatic hypotension, in which postural reflexes are slowed as part of the aging process.

Which assessment findings are clinical manifestations of aortic stenosis? (Select all that

apply.)

a. Jugular vein distention

b. Bounding pulses

c. Hypotension

d. Angina

e. Syncope

ANS: D, E

The classic manifestations of aortic stenosis are angina, syncope, and heart failure. None

of the other options are associated with aortic stenosis.

Which risk factors are associated with infective endocarditis? (Select all that apply.)

a. Rheumatic fever

b. Intravenous drug use

c. Long-term indwelling catheterization

d. Aortic regurgitation

e. Heart valve disease

ANS: B, C, E

Risk factors for infective endocarditis include acquired valvular heart disease, intravenous

drug abuse, long-term indwelling catheterization (e.g., for pressure monitoring,

hyperalimentation, or hemodialysis), and recent cardiac surgery. Neither rheumatic fever

nor aortic regurgitation is considered a risk factor for infective endocarditis.