The pericardium is:
a. the outer muscular layer of the heart.
b. the innermost layer of the heart chambers.
c. a membranous sac that encloses the heart.
d. the heart's fibrous skeleton.
ANS: C
The pericardium is the membranous sac that surrounds the heart. The outer layer that acts as
the fibrous skeleton of the heart is the myocardium. The innermost layer of the heart is the
endocardium.
REF: p. 570
A function of the pericardium is to:
a. provide a barrier against extracardial infections.
b. improve blood flow through the heart.
c. play a role in cardiac conduction.
d. assist in cardiac contraction.
ANS: A
A function of the pericardium is to provide a barrier against extracardial infections. The
pericardium does not improve blood flow through the heart as it is on the outside. The inner
portions of the heart control cardiac conduction. The muscular l
As a result of blockage in the pulmonary artery, blood would first back up into the:
a. aorta.
b. left ventricle.
c. pulmonary veins.
d. right ventricle.
ANS: D
Blockage in the pulmonary artery would cause blood to back up into the right ventricle, not
the aorta since these two vessels do not communicate. The pulmonary artery and left ventricle
do not communicate. Blockage in the pulmonary artery would not
Which chamber of the heart generates the highest pressure?
a. Right atrium
b. Left atrium
c. Left ventricle
d. Right ventricle
ANS: C
The left ventricle generates the highest pressure of all the heart's chambers.
REF: p. 571
The internal lining of the cardiovascular system is formed by what tissue?
a. Tunica adventitia
b. Connective
c. Mesothelium
d. Endothelium
ANS: D
The endothelium, not the tunica adventitia, is the lining of blood vessels. Connective tissues
help make up arterial walls but are not the lining of blood vessels. The mesothelium is a part
of the pericardial cavity.
REF: p. 570
A 20-year-old underwent an echocardiogram to assess chest pain. Results revealed a
congenital defect in the papillary muscles. Which of the following would the nurse expect to
occur?
a. Closure of the semilunar valve
b. Backward expulsion of the atriovent
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. Defects in the papillary muscles would not affect eit
Which structures act as anchors for the atrioventricular valves?
a. Chordae tendineae
b. Great vessels
c. Coronary ostia
d. Trabeculae carneae
ANS: A
The atrioventricular valve openings are attached to the papillary muscles by the chordae
tendineae. The great vessels are the vessels that bring blood to and out of the heart and are not
attached to the chordae tendineae. The coronary ostia are ope
Which statement indicates the nurse understands coronary ostia? The coronary ostia (the openings to the coronary arteries) are found in the:
a. left ventricle.
b. inferior vena cava.
c. coronary sinus.
d. aorta.
ANS: D
The ostia are found on the aorta, not the ventricle, the vena cava, or the coronary sinus.
REF: p. 573
What structure conducts action potentials down the atrioventricular septum?
a. Bachmann bundle
b. Bundle of His
c. Sinoatrial node
d. Atrioventricular node
ANS: B
The bundle of His conducts action potentials down the atrioventricular septum, not the
Bachmann bundle. The sinoatrial node conducts the potential along the atria while the
atrioventricular node conducts impulses to the ventricles.
REF: p. 576
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 innervatio
ANS: D
Cardiac impulses occur in the SA node because its cells depolarize more rapidly than other
automatic cells, not because of its superior location. The SA node is not the only area of the
heart capable of spontaneous depolarization. The SA node does
Which structures would not receive an electrical impulse when the patient is experiencing a
left bundle branch block?
a. Atrioventricular (AV) node
b. Sinoatrial (SA) node
c. Bundle of His
d. The left ventricle
ANS: D
The left bundle branch conducts impulses to the left ventricle; the AV node feeds conduction
of the bundles. The SA node initiates conduction while the bundle of His precedes the
division of the left and right bundles.
REF: p. 576
Depolarization of a cardiac muscle cell occurs as the result of:
a. a decrease in the permeability of the cell membrane to ions.
b. the rapid movement of ions across the cell membrane.
c. a blockade by calcium ions.
d. stimuli instigated during the refrac
ANS: B
Depolarization is caused by the movement of electrically charged solutes (ions) across cardiac
cell membranes. Permeability must be increased for movement to occur. A blockage of
calcium ions would decrease depolarization. No cardiac action potenti
What is the nurse monitoring when observing the QRS complex on the electrocardiogram?
a. Ventricular activity
b. Pulmonary artery closure
c. Mitral valve opening
d. Aortic valve closing
ANS: A
The QRS complex represents the sum of all ventricular muscle cell depolarizations, not the
closure of the pulmonary artery. The QRS complex does not reflect activity of either the
mitral or aortic valves.
REF: p. 577
What term is used to identify the period that follows depolarization of the myocardium and
represents a period during which no new cardiac potential can be propagated?
a. Absolute refractory
b. Hyperpolarization
c. Resting
d. Threshold
ANS: A
A refractory period is the time during which no new cardiac action potential can be initiated
by a stimulus. It follows depolarization. Neither hyperpolarization nor resting correctly
identifies this period. Threshold is related to depolarization.
The PR interval viewed on a normal electrocardiogram represents:
a. atrial depolarization.
b. ventricular depolarization.
c. onset of atrial activation to onset of ventricular activity.
d. "electrical systole" of the ventricles.
ANS: C
The PR interval represents the onset of atrial activation to the onset of ventricular activity.
The P wave represents atrial depolarization. The QRS complex represents ventricular
depolarization. The QT interval represents "electrical systole" of t
What represents the sum of all ventricular muscle cell depolarization?
a. PR interval
b. QRS complex
c. QT interval
d. P wave
ANS: B
The QRS complex represents the sum of all ventricular muscle cell depolarizations. The PR
interval represents the onset of atrial activation to the onset of ventricular activity. The QT
interval represents "electrical systole" of the ventricles. Th
A 13-year-old took a weight loss drug that activated the sympathetic nervous system. Which
of the following assessment findings would the nurse expect?
a. Decreased myocardial contraction
b. Decreased heart rate
c. Increased cardiac conduction
d. Increase
ANS: C
Stimulation of the SA node by the sympathetic nervous system rapidly increases cardiac
conduction. Stimulation of the sympathetic nervous system would increase myocardial
contraction and heart rate. Such simulation would not affect conduction time
A 50-year-old received trauma to the chest that caused severe impairment of the primary
pacemaker cells of the heart. Which of the following areas received the greatest damage?
a. Atrioventricular (AV) node
b. Sinoatrial (SA) node
c. Bundle of His
d. Vent
ANS: B
The SA node, not the AV node, is considered the pacemaker of the heart. Neither the bundle
of His nor the ventricles are involved.
REF: p. 576
A 28-year-old with seizure disorder has a vagus nerve stimulator implanted to help control
seizure activity. Which result will the nurse expect to occur?
a. Increased speed of cardiac cycle
b. Increased cardiac contractility
c. Decreased vasodilation
d. D
ANS: D
The vagus nerve releases acetylcholine. Acetylcholine causes decreased heart rate and slows
conduction through the AV node, thus decreasing the speed of the cardiac cycle. This reaction
also decreases contractility but does not cause decreased vaso
A nurse assesses the heart after acetylcholine because the effect of acetylcholine on the heart
is to:
a. decrease the refractory period.
b. increase calcium influx.
c. increase the strength of myocardial contraction.
d. decrease the heart rate.
ANS: D
Acetylcholine causes decreased heart rate and slows conduction through the AV node; it does
not decrease the refractory period nor does it increase calcium influx. It does not increase the
strength of myocardial contraction.
REF: p. 578
One difference between cardiac muscle and skeletal muscle is that:
a. cardiac muscle cells are arranged in branching networks.
b. skeletal muscle cells have only one nucleus.
c. cardiac muscle cells appear striped.
d. skeletal muscle cells contain sarcome
ANS: A
Cardiac cells are arranged in branching networks throughout the myocardium, whereas
skeletal muscle cells tend to be arranged in parallel units throughout the length of the muscle.
Cardiac muscle cells have only one nucleus, whereas skeletal muscle
What are the thickened areas of the sarcolemma of myocardial cells that enable electrical
impulses to travel in a continuous cell-to-cell fashion called?
a. Myosins
b. Intercalated disks
c. Troponin Ts
d. I bands
ANS: B
Intercalated disks allow electrical impulses to be transmitted rapidly from cardiac fiber to
cardiac fiber because the network of fibers is connected at these disks. Myosins do not play a
role in conduction. Troponin Ts are involved in contraction
Muscle contractions occur when there is a decreased:
a. distance between Z lines.
b. A band length.
c. Z line length.
d. H zone distance.
ANS: A
Anatomically, contraction occurs when the sarcomere shortens, so adjacent Z lines move
closer together. Such a contraction does not occur in relationship to a decrease in A band or Z
line length or a decrease in H zone distance.
REF: p. 581
The process by which an action potential in the plasma membrane of a myocardial cell
triggers the events that directly cause contraction of the myocardial cells is referred to as:
a. electrocontraction.
b. intercalated communication.
c. excitation-contrac
ANS: C
Excitation-contraction coupling, not electrocontraction, is the process by which an action
potential in the plasma membrane of the muscle fiber triggers the cycle, leading to
cross-bridge activity and contraction. Neither intercalated nor myosin co
The molecule that aids in bonding of the troponin complex to actin and tropomyosin is
troponin:
a. C.
b. I.
c. T.
d. M.
ANS: C
Troponin T aids in the binding of the troponin complex to actin and tropomyosin. Troponin C
contains binding sites for the calcium ions involved in contraction. Troponin I inhibits the
ATPase of actomyosin. Troponin M is not a substance.
REF: p. 58
A nurse is discussing the pressure generated at the end of diastole. Which term is the nurse
describing?
a. Preload
b. Afterload
c. Systemic vascular resistance
d. Total peripheral resistance
ANS: A
Preload, not afterload, is the volume and associated pressure generated in the ventricle at the
end of diastole. Afterload is the resistance to ejection of blood from the left ventricle.
Systemic vascular resistance is related to afterload. Total p
As stated by the Frank-Starling law, there is a direct relationship between the _____ of the
blood in the heart at the end of diastole and the _____ of contraction during the next systole.
a. pressure; duration
b. volume; force
c. viscosity; force
d. visc
ANS: B
The Frank-Starling law of the heart describes the length-tension relationship of ventricular
end-diastolic volume (VEDV) (preload) to myocardial contractility (as measured by stroke
volume). It does not refer to duration, pressure, or viscosity.
RE
Within a normal physiologic range, an increase in left ventricular end-diastolic volume would
lead the nurse to monitor for:
a. an increased force of contraction.
b. a decrease in cardiac output.
c. an increase in heart rate.
d. heart failure.
ANS: A
An increase in end-diastolic volume leads to an increased force of contraction because fibers
are stretched to handle increased volume. Cardiac output would increase. Although volume
increases, heart rate does not respond accordingly. An increase i
A 50-year-old was prescribed a drug that acts as a negative inotrope. Which endogenous
substances would be most similar?
a. Acetylcholine
b. Dopamine
c. Epinephrine
d. Thyroid hormone
ANS: A
The most important negative inotropic agent is acetylcholine. Dopamine, epinephrine, and
thyroid hormone are positive inotropes.
REF: p. 583
The primary cardiovascular control center is located in the:
a. cerebral cortex.
b. thalamus.
c. medulla.
d. hypothalamus.
ANS: C
The primary cardiovascular control center is in the brainstem in the medulla. The cerebral
cortex, the thalamus, and hypothalamus are secondary control sites.
REF: p. 583
After activation of the Bainbridge reflex in a patient, the nurse assesses for:
a. increased heart rate.
b. decreased blood pressure.
c. increased rate and depth of respirations.
d. decreased myocardial contractility.
ANS: A
Activation of the Bainbridge reflex increases heart rate. It does not decrease blood pressure, it
does not increase rate and depth of respirations, and it does not decrease myocardial
contractility.
REF: p. 583
A nurse observes a cardiologist multiplying the heart rate by stroke volume. What is the
cardiologist measuring?
a. Vascular resistance
b. Preload
c. Cardiac output
d. Ejection fraction
ANS: C
Cardiac output is found by the heart rate times stroke volume. Vascular resistance is not a
factor in the calculation of cardiac output; it does play a role in blood pressure. Preload affects
cardiac output but is not the result of heart rate times
Baroreceptors are located in the:
a. renal artery.
b. superior vena cava.
c. carotid artery.
d. circle of Willis.
ANS: C
Baroreceptors are found in the carotid arteries. They are not found in the renal artery, the
superior vena cava, or the circle of Willis.
REF: p. 583
Local myogenic regulation of blood vessel diameter and thus blood flow through a vessel is
an example of:
a. autonomic regulation.
b. somatic regulation.
c. autoregulation.
d. metabolic regulation.
ANS: C
The myogenic hypothesis proposes that autoregulation originates in vascular smooth muscle,
presumably of the arterioles, as a response to changes in arterial perfusion pressure. It is not a
part of autonomic, somatic, or metabolic regulation.
REF:
The thoracic lymphatic duct drains into the:
a. left subclavian artery.
b. right atrium.
c. right subclavian vein.
d. left subclavian vein.
ANS: D
The thoracic duct drains lymph into the left subclavian vein, not the right subclavian vein. The
right lymphatic duct drains into the right subclavian vein. The thoracic duct does not drain
lymph into the right atrium.
REF: p. 593
Blood flow is affected by: (select all that apply)
a. blood viscosity.
b. blood vessel diameter.
c. blood pressure.
d. blood vessel length.
e. blood composition.
ANS: A, B, C, D
Resistance to flow is generally greater in longer tubes because resistance increases with length
but decreases with a wider diameter. Blood flow varies inversely with the viscosity of the
fluid. Thick fluids move more slowly and experience
A nurse is evaluating stroke volume. Which of the following factors affect stroke volume?
(select all that apply)
a. Preload
b. Peripheral vascular resistance
c. Afterload
d. Ejection fraction
e. Contractility
ANS: A, C, E
Preload, afterload, and contractility affect stroke volume.
REF: p. 581