1. (1.0 point)
Approximately one third of the heart lies to the left of the midline of
the sternum. The remaining two thirds lie to the right of the sternum.
a. True
*b. False
Correct Answer Reply:
Approximately two thirds of the heart lie to the left of the
midline of the sternum. The remaining third lies to the right of the
sternum.
Incorrect Answer Reply:
Approximately two thirds of the heart lie to the left of the
midline of the sternum. The remaining third lies to the right of the
sternum.
2. (1.0 point)
Depolarization is the same as contraction.
a. True
*b. False
Correct Answer Reply:
Depolarization is not the same as contraction. Depolarization
(an electrical event) is expected to result in contraction (a
mechanical event). It is possible to see organized electrical activity
on the cardiac monitor, yet evaluation of the patient reveals no
palpable pulse. This clinical situation is called pulseless electrical
activity (PEA).
Incorrect Answer Reply:
Depolarization is not the same as contraction. Depolarization
(an electrical event) is expected to result in contraction (a
mechanical event). It is possible to see organized electrical activity
on the cardiac monitor, yet evaluation of the patient reveals no
palpable pulse. This clinical situation is called pulseless electrical
activity (PEA).
3. (1.0 point)
The base, or lower portion, of the heart is formed by the tip of the
left ventricle.
a. True
*b. False
Correct Answer Reply:
The base of the heart is its upper portion and is formed
mainly by the left atrium, with a small amount of right atrium. It lies
at approximately the level of the second intercostal space, immediately
in front of the esophagus and descending aorta. The heart’s apex, or
lower portion, is formed by the tip of the left ventricle. The apex
lies just above the diaphragm at approximately the level of the fifth
intercostal space in the midclavicular line.
,Incorrect Answer Reply:
The base of the heart is its upper portion and is formed
mainly by the left atrium, with a small amount of right atrium. It lies
at approximately the level of the second intercostal space, immediately
in front of the esophagus and descending aorta. The heart’s apex, or
lower portion, is formed by the tip of the left ventricle. The apex
lies just above the diaphragm at approximately the level of the fifth
intercostal space in the midclavicular line.
4. (1.0 point)
The period of time during the cardiac cycle when cells cannot respond
to a stimulus, no matter how strong, is called the relative refractory
period.
a. True
*b. False
Correct Answer Reply:
During the absolute refractory period (also known as the
effective refractory period), the cell will not respond to further
stimulation. This means that the myocardial working cells cannot
contract and the cells of the electrical conduction system cannot
conduct an electrical impulse—no matter how strong the stimulus.
Incorrect Answer Reply:
During the absolute refractory period (also known as the
effective refractory period), the cell will not respond to further
stimulation. This means that the myocardial working cells cannot
contract and the cells of the electrical conduction system cannot
conduct an electrical impulse—no matter how strong the stimulus.
5. (1.0 point)
Blood pressure is the result of cardiac output and peripheral vascular
resistance.
*a. True
b. False
Correct Answer Reply:
Blood pressure is equal to cardiac output × peripheral
vascular resistance. Blood pressure is the force exerted by the
circulating blood volume on the walls of the arteries. Peripheral
vascular resistance is the resistance to the flow of blood determined
by blood vessel diameter and the tone of the vascular musculature.
Incorrect Answer Reply:
Blood pressure is equal to cardiac output × peripheral
vascular resistance. Blood pressure is the force exerted by the
circulating blood volume on the walls of the arteries. Peripheral
vascular resistance is the resistance to the flow of blood determined
by blood vessel diameter and the tone of the vascular musculature.
,6. (1.0 point)
The heart is divided into _____ chambers but functions as a _____-sided
pump.
a. 2; 4
b. 3; 2
*c. 4; 2
d. 4; 3
Correct Answer Reply:
The heart has four chambers — two atria and two ventricles.
The right and left sides of the heart are separated by an internal wall
of connective tissue called a septum. The interatrial septum separates
the right and left atria. The interventricular septum separates the
right and left ventricles. The septa separate the heart into two
functional pumps. The right atrium and right ventricle make up one
pump. The left atrium and left ventricle make up the other.
Incorrect Answer Reply:
The heart has four chambers — two atria and two ventricles.
The right and left sides of the heart are separated by an internal wall
of connective tissue called a septum. The interatrial septum separates
the right and left atria. The interventricular septum separates the
right and left ventricles. The septa separate the heart into two
functional pumps. The right atrium and right ventricle make up one
pump. The left atrium and left ventricle make up the other.
7. (1.0 point)
In the heart's conduction system, the ____ receive(s) an electrical
impulse from the right and left bundle branches and relay(s) it to the
ventricular myocardium.
a. atrial pacemaker cells
*b. Purkinje fibers
c. atrioventricular (AV) node
d. sinoatrial (SA) node
Correct Answer Reply:
The right and left bundle branches divide into smaller and
smaller branches and then into a special network of fibers called the
Purkinje fibers. These fibers spread from the interventricular septum
into the papillary muscles. They continue downward to the apex of the
heart, making up an elaborate web that penetrates about one third of
the way into the ventricular muscle mass. The fibers then become
continuous with the muscle cells of the right and left ventricles.
Incorrect Answer Reply:
The right and left bundle branches divide into smaller and
smaller branches and then into a special network of fibers called the
Purkinje fibers. These fibers spread from the interventricular septum
into the papillary muscles. They continue downward to the apex of the
heart, making up an elaborate web that penetrates about one third of
the way into the ventricular muscle mass. The fibers then become
continuous with the muscle cells of the right and left ventricles.
, 8. (1.0 point)
Blood flows from the left atrium through the _____ valve into the left
ventricle.
*a. mitral
b. aortic
c. pulmonic
d. tricuspid
Correct Answer Reply:
Blood flows from the left atrium through the mitral (bicuspid)
valve into the left ventricle.
Incorrect Answer Reply:
Blood flows from the left atrium through the mitral (bicuspid)
valve into the left ventricle.
9. (1.0 point)
The anterior surface of the heart consists primarily of the:
a. left atrium.
b. right atrium.
c. left ventricle.
*d. right ventricle.
Correct Answer Reply:
The front (anterior) surface of the heart lies behind the
sternum and costal cartilages. It is formed by portions of the right
atrium and the left and right ventricles. However, because the heart is
tilted slightly toward the left in the chest, the right ventricle is
the area of the heart that lies most directly behind the sternum.
Incorrect Answer Reply:
The front (anterior) surface of the heart lies behind the
sternum and costal cartilages. It is formed by portions of the right
atrium and the left and right ventricles. However, because the heart is
tilted slightly toward the left in the chest, the right ventricle is
the area of the heart that lies most directly behind the sternum.
10. (1.0 point)
The intrinsic rate of the atrioventricular (AV) junction is:
a. 20 to 40 beats/min.
*b. 40 to 60 beats/min.
c. 60 to 80 beats/min.
d. 80 to 100 beats/min.
Correct Answer Reply:
The AV junction has pacemaker cells capable of firing at a
rate of 40 to 60 beats/min.
Incorrect Answer Reply:
Approximately one third of the heart lies to the left of the midline of
the sternum. The remaining two thirds lie to the right of the sternum.
a. True
*b. False
Correct Answer Reply:
Approximately two thirds of the heart lie to the left of the
midline of the sternum. The remaining third lies to the right of the
sternum.
Incorrect Answer Reply:
Approximately two thirds of the heart lie to the left of the
midline of the sternum. The remaining third lies to the right of the
sternum.
2. (1.0 point)
Depolarization is the same as contraction.
a. True
*b. False
Correct Answer Reply:
Depolarization is not the same as contraction. Depolarization
(an electrical event) is expected to result in contraction (a
mechanical event). It is possible to see organized electrical activity
on the cardiac monitor, yet evaluation of the patient reveals no
palpable pulse. This clinical situation is called pulseless electrical
activity (PEA).
Incorrect Answer Reply:
Depolarization is not the same as contraction. Depolarization
(an electrical event) is expected to result in contraction (a
mechanical event). It is possible to see organized electrical activity
on the cardiac monitor, yet evaluation of the patient reveals no
palpable pulse. This clinical situation is called pulseless electrical
activity (PEA).
3. (1.0 point)
The base, or lower portion, of the heart is formed by the tip of the
left ventricle.
a. True
*b. False
Correct Answer Reply:
The base of the heart is its upper portion and is formed
mainly by the left atrium, with a small amount of right atrium. It lies
at approximately the level of the second intercostal space, immediately
in front of the esophagus and descending aorta. The heart’s apex, or
lower portion, is formed by the tip of the left ventricle. The apex
lies just above the diaphragm at approximately the level of the fifth
intercostal space in the midclavicular line.
,Incorrect Answer Reply:
The base of the heart is its upper portion and is formed
mainly by the left atrium, with a small amount of right atrium. It lies
at approximately the level of the second intercostal space, immediately
in front of the esophagus and descending aorta. The heart’s apex, or
lower portion, is formed by the tip of the left ventricle. The apex
lies just above the diaphragm at approximately the level of the fifth
intercostal space in the midclavicular line.
4. (1.0 point)
The period of time during the cardiac cycle when cells cannot respond
to a stimulus, no matter how strong, is called the relative refractory
period.
a. True
*b. False
Correct Answer Reply:
During the absolute refractory period (also known as the
effective refractory period), the cell will not respond to further
stimulation. This means that the myocardial working cells cannot
contract and the cells of the electrical conduction system cannot
conduct an electrical impulse—no matter how strong the stimulus.
Incorrect Answer Reply:
During the absolute refractory period (also known as the
effective refractory period), the cell will not respond to further
stimulation. This means that the myocardial working cells cannot
contract and the cells of the electrical conduction system cannot
conduct an electrical impulse—no matter how strong the stimulus.
5. (1.0 point)
Blood pressure is the result of cardiac output and peripheral vascular
resistance.
*a. True
b. False
Correct Answer Reply:
Blood pressure is equal to cardiac output × peripheral
vascular resistance. Blood pressure is the force exerted by the
circulating blood volume on the walls of the arteries. Peripheral
vascular resistance is the resistance to the flow of blood determined
by blood vessel diameter and the tone of the vascular musculature.
Incorrect Answer Reply:
Blood pressure is equal to cardiac output × peripheral
vascular resistance. Blood pressure is the force exerted by the
circulating blood volume on the walls of the arteries. Peripheral
vascular resistance is the resistance to the flow of blood determined
by blood vessel diameter and the tone of the vascular musculature.
,6. (1.0 point)
The heart is divided into _____ chambers but functions as a _____-sided
pump.
a. 2; 4
b. 3; 2
*c. 4; 2
d. 4; 3
Correct Answer Reply:
The heart has four chambers — two atria and two ventricles.
The right and left sides of the heart are separated by an internal wall
of connective tissue called a septum. The interatrial septum separates
the right and left atria. The interventricular septum separates the
right and left ventricles. The septa separate the heart into two
functional pumps. The right atrium and right ventricle make up one
pump. The left atrium and left ventricle make up the other.
Incorrect Answer Reply:
The heart has four chambers — two atria and two ventricles.
The right and left sides of the heart are separated by an internal wall
of connective tissue called a septum. The interatrial septum separates
the right and left atria. The interventricular septum separates the
right and left ventricles. The septa separate the heart into two
functional pumps. The right atrium and right ventricle make up one
pump. The left atrium and left ventricle make up the other.
7. (1.0 point)
In the heart's conduction system, the ____ receive(s) an electrical
impulse from the right and left bundle branches and relay(s) it to the
ventricular myocardium.
a. atrial pacemaker cells
*b. Purkinje fibers
c. atrioventricular (AV) node
d. sinoatrial (SA) node
Correct Answer Reply:
The right and left bundle branches divide into smaller and
smaller branches and then into a special network of fibers called the
Purkinje fibers. These fibers spread from the interventricular septum
into the papillary muscles. They continue downward to the apex of the
heart, making up an elaborate web that penetrates about one third of
the way into the ventricular muscle mass. The fibers then become
continuous with the muscle cells of the right and left ventricles.
Incorrect Answer Reply:
The right and left bundle branches divide into smaller and
smaller branches and then into a special network of fibers called the
Purkinje fibers. These fibers spread from the interventricular septum
into the papillary muscles. They continue downward to the apex of the
heart, making up an elaborate web that penetrates about one third of
the way into the ventricular muscle mass. The fibers then become
continuous with the muscle cells of the right and left ventricles.
, 8. (1.0 point)
Blood flows from the left atrium through the _____ valve into the left
ventricle.
*a. mitral
b. aortic
c. pulmonic
d. tricuspid
Correct Answer Reply:
Blood flows from the left atrium through the mitral (bicuspid)
valve into the left ventricle.
Incorrect Answer Reply:
Blood flows from the left atrium through the mitral (bicuspid)
valve into the left ventricle.
9. (1.0 point)
The anterior surface of the heart consists primarily of the:
a. left atrium.
b. right atrium.
c. left ventricle.
*d. right ventricle.
Correct Answer Reply:
The front (anterior) surface of the heart lies behind the
sternum and costal cartilages. It is formed by portions of the right
atrium and the left and right ventricles. However, because the heart is
tilted slightly toward the left in the chest, the right ventricle is
the area of the heart that lies most directly behind the sternum.
Incorrect Answer Reply:
The front (anterior) surface of the heart lies behind the
sternum and costal cartilages. It is formed by portions of the right
atrium and the left and right ventricles. However, because the heart is
tilted slightly toward the left in the chest, the right ventricle is
the area of the heart that lies most directly behind the sternum.
10. (1.0 point)
The intrinsic rate of the atrioventricular (AV) junction is:
a. 20 to 40 beats/min.
*b. 40 to 60 beats/min.
c. 60 to 80 beats/min.
d. 80 to 100 beats/min.
Correct Answer Reply:
The AV junction has pacemaker cells capable of firing at a
rate of 40 to 60 beats/min.
Incorrect Answer Reply:
