ch. 20 Flashcards
the right side of the heart receives blood from the body and pumps through _____ circulation to the lungs.
a. hepatic
b. pulmonary
c. peripheral
d. systemic
pulmonary
the delivery of oxygen and nutrients to the tissues of the body is accomplished through _____ circulation
a. hepatic
b. pulmonary
c. peripheral
d. systemic
systemic
which of the following is NOT a function of the heart
a. providing a location for gas exchange between oxygen and carbon dioxide
b. regulating blood supply to tissues depending on need
c. generating blood pressure through contraction
d. routing blood to either the pulmonary or systemic circulations
providing a location for has exchange between oxygen and carbon dioxide
which of the following is NOT true about the heart
a. the heart is about the size of a closed fist
b. the heart is located in the mediastinum
c. the apex of the heart is directed superiorly and to the left
d. knowing the heart’s position is important for effective CPR
the apex of the heart is directed superiorly and to the left
the heart
a. is a four-chambered muscular pump
b. is posterior to the trachea
c. is lined with an epithelial layer called epicardium
d. lies mostly to the right of the midline of the sternum
e. has a superior apex and an inferior base
is a four-chambered muscular pump
the pericardial sac is lined with
a. fibrous pericardium
b. parietal pericardium
c. visceral pericardium
d. myocardium
e. epicardium
parietal pericardium
the epicardium
a. covers the surface of the heart
b. lines the walls of the ventricles
c. is known as the fibrous pericardium
d. attaches inferiorly to the diaphragm
e. is also called endocardium
covers the surface of the heart
a serious condition in which a large amount of fluid accumulates in the pericardial cavity and puts pressure of the heart is
a. endocarditis
b. pericarditis
c. myocardial infarction
d. cardiac tamponade
cardiac tamponade
E.Z. Goen is admitted to the cardiac unit with a diagnosis of endocarditis. when EZ asks the nurse where the infection is located, the nurse replies that the infection is in
a. the outer layer of the heart wall
b. the inner lining of the heart
c. a membranous sac that encloses the heart wall
d. the muscular layer of the heart
d. the lining of the mediastinum
the inner lining of the heart
another name for the visceral pericardium is the
a. endocardium
b. epicardium
c. isocardium
d. myocardium
e. cisocardium
epicardium
which of the following pairs is mismatched
a. endocardium - covers the inner surfaces of the heart
b. myocardium - cardiac muscle
c. trabeculae carneae - interior walls of ventricles
d. pectinate muscles - muscles that close valves
e. chordae tendineae - connective tissue strings that connect to cusps of valves
pectinate muscles - muscles that close valves
a stab wound into the heart can result in cardiac tamponade. this means that
a. blood enters the pleural cavity
b. the heart is compressed by blood in the pericardiac sac
c. the electrical conduction system of the heart is damaged
d. the left coronary artery has been damaged or cut
e. the heart has lost all of its blood
the heart is compressed by blood in the pericardiac sac
which of the following layers forms the bulk of the heart wall
a. epicardium
b. pericardium
c. endocardium
d. myocardium
e. visveral pericardium
myocardium
the function of the pericardial fluid is to
a. reduce friction between the pericardial membranes
b. lubricate the heart valves
c. replace any blood that is lost
d. provide oxygen and nutrients to the endocardium
e. stimulate the heart
reduce friction between the pericardial membranes
blood vessels enter and exit from the ____ of the heart
a. apex
b. base
c. auricles
d. trigone
e. inferior aspect
base
blood in the pulmonary veins returns to the
a. right atrium
b. left atrium
c. right ventricle
d. left ventricle
e. coronary sinus
b. left atrium
the great cardiac vein and middle cardiac vein empty into a venous cavity called the
a. pumonar vein
b. inferior vena cava
c. superior vena cava
d. coronary sinus
e. coronary artery
coronary sinus
all cardiac veins empty into the ____, which the empties into the ____
a. coronary sinus; left atrium
b. coronary sinus; right atrium
c. great cardiac vein; right atrium
d. great cardiac vein; superior vena cava
e. inferior vena cava; left atrium
coronary sinus; right atrium
occlusion of which of the following would primarily damage the posterior wall of the heart
a. circumflex artery
b. pumonary artery
c. right marginal
d. coronary sinus artery
e. right coronary artery
circumflex artery
which of these statements is true
a. the left coronary artery is a branch of the left pulmonary vein
b. the coronary sinus returns blood to the left atrium
c. the coronary arteries arise from the pulmonary trunk
d. the great cardiac vein collects blood from the left anterior surface of the heart
e. the pulmonary arteries carry blood to the left atrium
the great cardiac vein collects blood from the left anterior surface of the heart
a direct connection between arteries is called a/an
a. auricle
b. sulcus
c. sinus
d. anastamosis
anastamosis
blood flow throught the coronary blood vessels decreases during myocardial contraction and increases during myocardial relaxation
true or false
true
coronary artery disease can diminish myocardial blood flow resulting in the death of myocardial cells. this condition is known as a myocardial
a. atteck
b. angina
c. necrosis
d. cirrhosis
e. infarction
infarction
the procedure whereby a small balloom is placed into a partially occluded coronary artery and then inflated to increase blood blow through the artery is called a(n)
a. angioplasty
b. coronary bypass
c. urokinase injection
d. tissue plasminogen activation
e. angiogram
angioplasty
which of the following is NOT a major opening into the right atrium
a. pulmonary vein
b. inferior vena cava
c. superior vena cava
d. coronary sinus
pulmonary vein
angina pectoris is chest pain caused by reduced
a. stimulation of the myocardium
b. blood supply to cardiac muscle
c. fluid in the pericardial sac
d. contratility of the heart
e. action potentials from SA node
blood supply to cardiac muscle
which of the following is NOT an enzyme given to someone experiencing a myocardial infarction to break up blood clots
a. streptokinase
b. tissue plasminogen activator (t-Pa)
c. nitroglycerin
d. uronkinase
nitroglycerin
what is the foramen ovale
a. an opening between the right and left atria in the embryo and fetus
b. an opening between the right and left ventricles in the embryo and fetus
c. an oval hole in the pericardium in the embryo and fetus
d. an opening between teh pulmonary trunk and aorta in the embryo and fetus
an opening between the right and left atria in the embryo and fetus
the right atrium receives blood from
a. the lungs and the heart
b. the heart
c. the body and the heart
d. the lungs and the body
the body and the heart
what vessel exits the left ventricle
a. pulmonary trunk
b. pulmonary vein
c. aorta
d. pulmonary artery
aorta
the AV valve that is located on the same side of the heart as the origin of the aorta is the
a. bicuspid or mitral valve
b. tricuspid valve
c. aortic semilunar valve
d. pulmonary semilunar valve
e. coronary sinus valve
bicuspid or mitral valve
the valve located between teh right ventricle and the pulmonary trunk is the
a. aortic semilunar valve
b. pulmonary semilunar valve
c. tricuspid valve
d. mitral valve
e. bicuspid valve
b. pulmonary semilunar valve
contraction of the papillary muscles would
a. eject blood from the ventricles
b. prevent the AV valves from protruding into the atria
c. close the semilunar valves
d. cause the atria to eject their contents into the ventricles
e. open the semilunar valves
prevent the AV vaves from protruding into the atria
the chordae tendineae
a. connect the atria to the ventrices
b. are found in the interventricular septum
c. are part of the conducting system of the heart
d. connect the flaps of the AV valves to the papillary muscles
e. are a part of the myocardium
connect the flaps of the AV valves to the papillary muscles
blood in the superior vena cava will enter the ____
a. aorta
b. right atruim
c. pulmonary trunk
d. pulmonary arteries
e. pulmonary veins
right atrium
which vessels empty blood into the left atrium
a. aorta
b. right atrium
c. pulmonary trunk
d. pulmonary arteries
e. pulmonary veins
pulmonary veins
which blood vessel carries blood from the left ventricle
a. aorta
b. right atruin
c. pulmonary trunk
d. pulmonary arteries
e. pulmonary veins
aorta
from the right ventricle, blood flows directly into the ____
a. aorta
b. right atrium
c. pulmonary trunk
d. pulmonary arteries
e. pulmonary veins
pulmonary trunk
which vessels transport blood to the right and left lungs
a. aorta
b. right atrium
c. pulmonary trunk
d. pulmonary arteries
e. pulmonary veins
pulmonary arteries
an incompetent pulmonary semilunar valve could result in less blood reaching the
a. lungs
b. heart muscle
c. right ventricle
d. aorta
e. right atrium
lungs
which of the following heart chambers is correctly associated with the blood vessel that enters or leaves it
a. right atrium - pulmonary veins
b. left atrium - aorta
c. right ventricle - pulmonary trunk
d. left ventricle - superior vena cava and interior vena cava
e. right atrium - aorta
right ventricle - pulmonary trunk
which of the following is a function of the heart skeleton
a. provides electrical insulation between the atria and ventricles
b. supplies support and reinforcement for the the valves
c. provides a rigid site for cadiac muscle attachment
d. all of the choices are functions of the heart skeleton
all of the choices are functions of the heart skeleton
which of the following phrases would apply to cardiac muscle cells
a. are organized in parallel columns or bundles
b. contain actin but no myosin
c. develop a significant oxygen debt during systole
d. are multinucleated like skeletal muscle cells
e. possess special cell-to-cell contacts called intercalated discs
possess special cell-to-cell contacts called intercalated discs
cardiac muscle cells
a. have smooth ER but no T tubules
b. form the heart valves
c. are maintained by an extensive capillary network
d. develop a significant oxygen debt during systole
e. do not contain actin and myosin like skeletal muscle cells
are maintained by an extensice capillary network
action potentials pass from one myocardial cell to another through areas of low electrical resistance called
a. gap junctions
b. fibrous heart rings
c. electromagnetic discs
d. sarcolemma sclerotic plaques
e. tight junctions
gap junctions
the “pacemaker” of the heart is the
a. right bundle branch
b. left bundle branch
c. AV node
d. SA node (SI?)
e. PM node
SA node (SI?)
which of the following sequences for the conducting system is correct
a. AV node, AV bundle, SA node, Purkinje fibers, bundle branches
b. Purkinje fibers, bundle branches, AV node, AV bundle, SA node
c. SA node, AV node, AV bundle, bundle branches, Purkinje fibers
d. SA node, AV bundle, AV node, bundle branches, Purkinje fibers
e. AV node, SA node, bundle branches, AV bundle, Purkinje fibers
SA node, AV node, AV bundle, bundle branches, Purkinje fibers
what is the important of the delay in the action potential in the AV node
a. it allows the action potential to reach both ventricles at the same time
b. it allows action potential to reach the left atrium so both atria contract together
c. it slows the rate of contraction of the ventricles
d. it allows time for the atria to be filled with blood
it allows an action potential to reach the left atrium potential to reach the left atrium so both atria contract together
energy for contraction of the myocardial cells comes primarily from
a. aerobic respiration in the mitochondria
b. anaerobic respiration in the cytosol
c. glycolysis in the cytosol
d. ATP that is stored white the heart is not contracting
e. creatine phosphate
aerobic respiration in the mitochondria
the cardiac electrical impulse normally begins spontaneously in the SA node because
a. of the superior location of the SA node in the right atrium
b. the SA node is the only area of the heart capable of spontaneous depolarization
c. of the rich sympathetic innervation of the SA node
d. this area produces action potentials more rapidly than any other portion of the conduction system
e. of action potentials from the cardioregulatory center
this area produces action potentials more rapidly than any other portion of the conduction system
which of the following will depolarize immediately after the AV node depolarizes
a. the AV bundle
b. Purkinje fibers
c. atrial myocardium
d. bundle branches in the ventricular septum
e. the SA node
the AV bundle
ventricular contraction begins at the
a. AV bundle
b. apex of the heart
c. base of the heart
d. superior portion of the interventricular septum
e. top of the ventricles
apex of the heart
the action potentials are slowed at the AV nbode to allow the
a. ventricles to repolarize
b. ventricles to completely empty of blood
c. pacemaker to reset for the next beat
d. atria to complete their contraction
e. atria to begin their contraction
atria to complete their contraction
the spontaneous opening of sodium channels marks the beginning of ____ of a myocardial cell
a. depolarization
b. repolarization
c. hyperpolarization
d. isopolarization
e. afterpolarization
depolarization
the plateau phase seen during the action potential of a cardiac muscle cell is due to the
a. sodium-potassium pump
b. opening of socium channels
c. continuing to have open calcium channels
d. closure of chloride channels
e. chlosing calcium channels
continuing to have open calcium channels
when a pacemaker potential in the SA node reaches threshold
a. the permeability to K+ ions increases
b. many voltage-gated Ca2+ channels open
c. voltage-gated Ca2+ channels close
d. RMP has been restored
e. permeability of the cell does not change
many voltage-gated Ca2+ channels open
if the SA node is nonfunctional, which of the following is most likely to occur
a. the heart will go into asystole (stop)
b. tachycardia will develop
c. another portion of the heart will become the pacemaker
d. the heart will go into defibrilation
e. the heart wil be desensitized
another portion of the heart will become the pacemaker
which of the following events occurs first
a. threshold
b. depolarization
c. early repolarization
d. dinal repolarization
e. pacemaker potential
pacemaker potential
calcium channel blockers are frequently used to
a. increase the heart rate
b. treat tachycardia or other arrhythmias
c. speed up conduction of impulses through the AV node
d. slow the closing of potassium ion channels
e. treat bradycardia and low blood pressure
treat tachycardia or other arrhythmias
depolarization of a cardiac muscle cell occurs as the result of
a. a decrease in the permeability of the cell membrane to sodium
b. the opening of the voltage-gated sodium channels and voltage-gated calcium channels
c. the closure of voltage-gated calcium channels
d. the opening of voltage-gated potassium channels
e. the closure of the voltage-gated sodium channels
the opening of the voltage-gated sodium channels and voltage-gated calcium channels
when comparing cardiac muscle cells and skeletal muscle cells
a. the rate of action potential propagation is faster in cardiac musvle
b. both possess intercalated discs
c. only skeletal muscle has a plateau phase in its contraction cycle
d. action potentials are conducted from cell to cell only in cardiac muscle
e. both are voluntary
action potentials are conducted from cell to cell only in cardiac muscle
what action is most responsible for the resting membrane potential in cardiac muscle cells
a. movement of K+ through voltage-gated K+ channels
b. movement of Na+ through open Na+ channels
c. movement of Ca2+ though voltage-gated Ca2+ channels
d. closing of Na+ and K+ voltage-gated channels
movement of K+ through voltage-gated K+ channels
which of the following is mismatched
a. opening of the sodium channels - depolarization
b. closing of calcium channels - plateau phase
c. opening of potassium channels - rapid repolarization
d. closure of sodium channels - early repolarization
e. opening of calcium channels - plateau phase
closing of calcium channels - plateau phase
which of the following would result from a reduced function of the sodium channels in the SA node
a. depolarization would be delayed
b. the heart rate would decrease
c. repolarization woud not occur
d. a shortened plateau phase
e. depolarization would be delayed and the heart rate would decrease
depolarization would be delayed and the heart rate would decrease
which of the following areas of the conduction system would produce spontaneous action potentials most frequently if the SA node were not functioning
a. AV bundle
b. Purkinje fibers
c. AV node
d. bundle branch
e. the pacemaker
AV node
the long refractory period observed in cardiac muscle
a. porlongs depolarization of the cardiac muscle
b. prevents tetanic contractions of the cardiac muscle
c. ensures that the heart has adequate time to contract
d. prevents the heart rate from slowing down
e. prevents an increase in heart rate
prevents tetanic contractions of the cardiac muscle
the period of time in which the myocardium is insensitive to further stimulation is called the
a. absolute refractory period
b. hyperpolarization on period
c. AV period
d. SA period
e. extopic focus
absolute refractory period
if cardiac muscle cells are unable to repolarize, this would cause
a. cardiac output to increase
b. no harm, these cells spontaneously depolarize anyway
c. the heart rate to decrease, it might cause cardiac arrest
d. an increased demand on mitochondria to produce more ATP
e. tachycardia
the heart rate to decrease, it might cause cardiac arrest
in a normal electrocardiogram, the
a. P wave results from repolarization of the atria
b. QRS complex resutls from ventricular depolarization
c. P wave occurs after the QRS complex but before the T wave
d. T wave represents depolarization of the atria
e. repolarization of the atria is clearly visble
QRS complex results from ventricular depolarization
the P wave of an EOG indicates
a. atrial depolarization
b. atrial repolarization
c. ventricular depolarization
d. ventricular repolarization
e. threshold
atrial depolarization
of the types of damage resulting from myocardial infarction, which is most likely to cause the greatest increase in the Q-T interval
a. infarction in the AV node
b. left bundle branch block
c. infarction affecting the SA node
d. tachycardia
e. ectopic focus
left bundle branch block
what event(s) occur during the QRS complex ECG
a. depolarization of the atria
b. repolarization of the ventricles
c. depolarization of the atria and repolarization of the ventricles
d. depolarization of the ventricles and repolarization of the atria
depolarization of the ventricles and repolarization of the atria
what abnormal heart rhythm could be caused by an elevated body temperature, excessive sympathetic stimulations, or toxic conditions
a. bradycardia
b. atrial fibrillation
c. second-degree AV node block
d. tachycardia
tachycardia
what cardiac arrhythmia will have no QRS complex as a symptom
a. atrial fibrillation
b. ventricular fibrillation
c. bradycardia
d. premature ventricular contractions
ventricular fibrillation
variations in respiratory rate is a symptom of
a. sinus arrhythmia
b. ventricular tachycardia
c. SA node block
d. paroxysmal atrial tachycardia
sinus arrhythmia
contraction of the ventricles is referred to as ventricular
a. systole
b. diastole
c. fibrillation
d. ischemia
e. depolarization
systole
in the cardiac cycle
a. the right atrium and the right ventricle contract simultaneously
b. the two atria relax while the two ventricles contract
c. the left atrium contracts before the right atrium
d. all four chambers of the heart contract at the same time
e. all four chambers of the heart are in systole at the same time
the two atria relax while the two ventricles contract
in the cardiac cycle
a. the right atrium and the right ventricle contract simultaneously
b. the left atrium contracts before the right atrium
c. all four chambers of the heart contract at the same time
d. all four chambers of the heart are in diastole at the same time
all four chambers of the heart are in diastole at the same time
the period of isovolumetric contraction is immediately followed by
a. the period of ejection
b. AV node depolarization
c. passive ventricular filling
d. atrial contraction
e. isocolumetric relaxation
the period of ejection
when left atrial pressure exceeds left ventricular pressure
a. let ventricular ejection begins
b. aortic blood pressure begins to rise
c. the bicuspid (mitral) valve opens
d. ventricular volume decreases
e. the tricuspid valve opens
the bicuspid (mitral) valve opens
blood does not enter or leace the ventricles during the period called
a. ejection
b. rapid filling
c. atrial systole
d. isovolumetric contraction
e. active and passive filling
isovolumetric contraction
during ejection phase of the cardiac cycle, blood exits the left ventricle through the
a. aorta
b. coronary sinus
c. pulmonary vein
d. superior vena cava
e. pulmonary trunk
aorta
pressure in the right ventricle must exceed pressure in the ______ before the right ventricle can eject blood
a. superior vena cava
b. coronary sinus
c. pulmonary trunk
d. aorta
e. pulmonary veins
pulmonary trunk
the chamber of the heart the highest pressure is the
a. right atrium
b. left atrium
c. right ventricle
d. left ventricle
e. coronary sinus
left ventricle
the tricuspid valve is closed
a. during active ventricles
b. when the mitral valve is open
c. while the atria are contracting
d. during ejection
e. during passive filling the of ventricles
during ejection
as soon as left ventricular pressure exceeds the pressure in the aorta, the
a. AV valves open
b. aortic semilumar valve opens
c. atria pump blood into the ventricles
d. ventricles pump blood into the atria
e. pulmonary semilunar valve closes
aortic semilunar valve opens
during the isovolumetric contraction period of the cardiac cycle,
a. AV and semilunar valves are closed
b. the atria are contracted
c. ventricular volume increases
d. blood is pumped into the large arteries
e. pressure in the ventricles decreases
AV and semilunar valves are closed
when ventricular pressure exceeds atrial pressure, the
a. ejection occurs
b. atria pump blood into the ventricles
c. ventricle is in diastole
d. blood is pumped into the atrium
e. AV valve close
AV valves close
what occurs during the time between the first heart sound and the second heart sound
a. ventrcular systole
b. ventricular diastole
c. ventricular filling
d. atrial systole
e. the P wave of the ECG
ventricular systole
concerning heart sounds, which of the following is correct
a. the first heart sound occurs at the beginning of ventricular systole
b. the second heart sound is heard when the AV vaves are closing
c. the first heart souns is the sound of the semilunar valves closing
d. the second heart sound occurs when blood flows into the superior vena cava
e. the first heart sound occurs at the beginning of ventricular diastole
the first heart sound occurs at the beginning of ventricular systole
b. the second heart sound is heard when the AV vaves are closing
The first and second heart sounds are most directly related to
A. pulse pressure in the aorta.
B. the contraction of the atria.
C. vibrations that occur when the valves close.
D. contraction of the papillary muscles. E. the flow of the blood.
C. vibrations that occur when the valves close.
Which of the following is true?
A. Blood enters the right and left atria only during diastole.
B. Most ventricular filling occurs before the atria contract.
C. During ventricular systole, the AV valves open.
D. The semilunar valves remain closed throughout ventricular systole.
E. Most of end-diastolic volume comes from active filling.
B. Most ventricular filling occurs before the atria contract.
Regurgitation of blood flow through the aortic semilunar valve would give rise to
A. the first heart sound.
B. the second heart sound.
C. a heart murmur.
D. an extra heart beat.
E. end-systolic volume.
C. a heart murmur.
An incompetent mitral valve may cause blood to back up into the
A. aorta.
B. left atrium.
C. left ventricle.
D. coronary circulation.
E. right atrium.
B. left atrium.
The volume of blood pumped during each cardiac cycle is the
A. stroke volume.
B. cardiac output.
C. cardiac reserve.
D. end-systolic volume.
E. end-diastolic volume.
A. stroke volume.
The product of the stroke volume times the heart rate is known as the
A. end-diastolic volume.
B. end-systolic volume.
C. cardiac output.
D. cardiac reserve.
E. venous return.
C. cardiac output.
End-diastolic volume minus end-systolic volume is equal to
A. cardiac output.
B. cardiac reserve.
C. pulse volume.
D. venous return.
E. stroke volume.
E. stroke volume.
Mean arterial pressure is
A. cardiac output times peripheral resistance.
B. end-diastolic volume minus end-systolic volume.
C. maximum cardiac output minus cardiac output when at rest.
D. heart rate times stroke volume.
E. stroke volume times peripheral resistance
A. cardiac output times peripheral resistance.
The dicrotic notch in the aortic pressure curve is due to the
A. increase in intraventricular pressure during ejection.
B. backflow of blood toward the ventricles.
C. closure of the left AV valve.
D. elasticity of the arterial wall.
E. closure of the semilunar valves.
B. backflow of blood toward the ventricles.
Afterload is
A. the name given to an increase in end-diastolic volume.
B. the arterial pressure that the ventricles must overcome to eject blood.
C. the amount cardiac output must increase during exercise.
D. another name for venous return.
E. the extent to which ventricular walls are stretched.
the arterial pressure that the ventricles must overcome to eject blood.
Which of the following statements regarding intrinsic regulation of the heart is true?
A. Stretching the SA node will decrease generation of action potentials in the node.
B. Decreased venous return increases cardiac output.
C. The heart’s pumping effectiveness is greatly influenced by small changes in afterload.
D. If cardiac muscle fibers are slightly stretched, they have a stronger contraction force.
E. If cardiac muscle fibers are slightly stretched, they have a weaker contraction force.
D. If cardiac muscle fibers are slightly stretched, they have a stronger contraction force.
Within normal limits, an increase in preload leads to
A. an increase in cardiac output and force of left ventricular contraction.
B. a decrease in cardiac output and force of left ventricular contraction.
C. an increase in cardiac output and a decrease in force of left ventricular contraction.
D. a decrease in cardiac output and an increase in the force of left ventricular contraction.
E. a decrease in stroke volume and heart rate.
A. an increase in cardiac output and force of left ventricular contraction.
The relationship between preload and stroke volume is known as
A. extrinsic regulation.
B. cardiac reserve.
C. Starling Law of the heart.
D. minute volume.
C. Starling Law of the heart.
Stimulation of the heart via the sympathetic nerves would
A. decrease heart rate.
B. decrease stroke volume.
C. increase the force of ventricular contraction.
D. increase end-systolic volume.
E. not affect heart rate and force of contraction.
C. increase the force of ventricular contraction.
If the heart receives more sympathetic stimulation than parasympathetic stimulation, the heart will
A. increase its rate and force of contraction.
B. contract with greater force but at a slower rate.
C. decrease both its rate and force of contraction.
D. contract with less force but at a faster rate.
E. decrease rate, but increase force of contraction.
A. increase its rate and force of contraction.
Increased vagal stimulation would cause
A. the heart rate to decrease.
B. the heart rate to increase.
C. force of contraction to increase.
D. stroke volume to increase.
E. no change in heart rate, stroke volume, or force of contraction.
A. the heart rate to decrease.
Which of the following factors would cause an increase in heart rate?
A. increased parasympathetic stimulation
B. stimulation of baroreceptors in the aorta
C. increased epinephrine release from the adrenal medulla
D. increased production of atrial natriuretic factor
E. vagal stimulation
C. increased epinephrine release from the adrenal medulla
The baroreceptor reflex would cause which of the following events to occur if the reflex was caused by an increase in blood pressure?
A. increased parasympathetic stimulation of the heart
B. increased heart rate
C. increased cardiac output
D. increased force of contraction
E. increased sympathetic stimulation of the heart
A. increased parasympathetic stimulation of the heart
Baroreceptor reflexes
A. are triggered by increased blood osmolality.
B. correct changes in blood pH.
C. do not impact the activity of the heart.
D. are of minor importance in humans.
E. can change heart rate.
E. can change heart rate.
In a physiology lab, the students designed an experiment to illustrate how the heart responds to changes in blood pressure. Everyone relaxed and then did a headstand. Which of the following observations are consistent with the change in the function of their hearts?
A. increased heart rate
B. decreased heart rate
C. increased stroke volume
D. decreased stroke volume
E. both decreased heart rate and increased stroke volume
E. both decreased heart rate and increased stroke volume
Which of the following will increase the heart rate?
A. a rise in pH
B. an increase in the level of carbon dioxide in the blood
C. an increase in the level of blood oxygen
D. an increase in blood pressure
E. a decrease in the level of carbon dioxide in the blood
B. an increase in the level of carbon dioxide in the blood
The cardioregulatory center of the brain is located in the
A. hypothalamus.
B. medulla oblongata.
C. cerebellum.
D. cerebrum.
E. diencephalons.
B. medulla oblongata.
Chemoreceptors sensitive to blood carbon dioxide levels are primarily located in the
A. medulla oblongata.
B. carotid arteries.
C. right atrium.
D. left ventricle.
E. jugular veins.
A. medulla oblongata.
Chemoreceptors sensitive to blood oxygen levels are primarily located in the
A. medulla oblongata.
B. carotid arteries.
C. right atrium.
D. left ventricle.
E. jugular veins.
B. carotid arteries.
An increase in extracellular calcium generally increases
A. the heart rate.
B. the force of contraction.
C. autonomic stimulation of the heart.
D. sodium channel opening.
E. the frequency of the action potentials.
B. the force of contraction.
Excess potassium ions in cardiac tissue cause
A. an increased heart rate.
B. a rapid repolarization of cardiac cells.
C. a decrease in the frequency of action potentials in the conduction system.
D. an increase in stroke volume.
E. an increase in the frequency of action potentials.
C. a decrease in the frequency of action potentials in the conduction system.
Lowered extracellular potassium levels will lower the heart rate because
A. the resting membrane potential is hyperpolarized.
B. ectopic action potentials occur.
C. action potential amplitude declines.
D. more sodium channels open.
E. it blocks calcium channels.
A. the resting membrane potential is hyperpolarized.
Why is body temperature sometimes reduced during heart surgery?
A. to slow respiration
B. to increase heart rate
C. to decrease heart rate
D. to increase the oxygen content of blood
C. to decrease heart rate
Aortic stenosis results from
A. a hole in the interatrial septum.
B. a weakening of heart muscle.
C. a narrowed opening through the aortic valve.
D. low oxygen levels.
E. leakage from the AV valves.
C. a narrowed opening through the aortic valve.
Which of the following might increase the risk for cardiovascular disease?
A. stopping smoking
B. exercise
C. maintaining normal cholesterol levels
D. chronic stress
E. lots of fiber in the diet
D. chronic stress
fred was admitted to the cardiac unit with chest pains. No arrhythmias and no large changes in the heart rate were observable. Blood samples taken over the next few days showed no increase in enzymes such as creatine phosphokinase. A possible treatment of the condition is
A. beta adrenergic blocking agents.
B. nitroglycerin.
C. calcium channel blocking agents.
D. aspirin.
E. exercise.
B. nitroglycerin.
During hemorrhagic shock in which blood pressure is decreased, which of the regulatory mechanisms is most important is increasing cardiac output to help maintain blood pressure?
A. increased sympathetic stimulation of the heart
B. increase venous return
C. increase in parasympathetic stimulation of the heart
D. increase vagal stimulation of the heart
E. increase in the amplitude of the heart sounds
A. increased sympathetic stimulation of the heart
