ch 17 practice quizzes
End-diastolic volume (EDV) for each ventricle at the end of atrial systole is normally about:
120 ml
Which of the following can be used to measure heart rate? Q-T interval P-R interval S-T segment R-R interval
R-R interval
What valve prevents the backflow of blood from the right ventricle into the right atrium? -aortic valve -bicuspid (mitral) valve -tricuspid valve -pulmonary valve
tricuspid valve
Heart rate can be determined by measuring the time between two successive R waves on an electrocardiogram (ECG), known as the R-R interval. T/F
true
The cardiac conduction system is normally regulated by a population of pacemaker cells known as the sinoatrial (SA) node. T/F
true
The left side of the heart is often called the systemic pump due to blood flow to the body. T/F
true
The left ventricle has greater muscle mass than the right ventricle since it pumps against greater resistance. T/F
true
The sinoatrial (SA) node fires more rapidly at higher body temperatures, increasing cardiac output. T/F
true
The sympathetic nervous system increases cardiac output by increasing both heart rate and stroke volume. T/F
true
Which cranial nerves have a negative chronotropic effect on heart rate? -trochlear nerves (CN IV) -vagus nerves (CN X) -hypoglossal nerves (CN XII) -glossopharyngeal nerves (CN IX)
vagus nerves (CN X)
Both the left and right atria receive blood from: -the ventricles. -veins. -the lungs. -arteries.
veins
What vessel(s) deliver oxygenated blood to the left atrium? -pulmonary veins -aorta -pulmonary trunk -pulmonary arteries
pulmonary veins
The volume of blood pumped by each ventricle in one heartbeat is known as: -stroke volume (SV). -heart rate (HR). -end-diastolic volume (EDV). -cardiac output (CO).
stroke volume (SV)
During what phase does blood flow from the ventricles into the pulmonary trunk and aorta? -ventricular filling -ventricular ejection phase -isovolumetric relaxation phase -isovolumetric contraction phase
ventricular ejection phase
Place the following parts of the cardiac conduction system in the order in which they transmit the action potential. 1.atrioventricular (AV) bundle 2.Purkinje fibers 3.sinoatrial (SA) node 4.right and left bundle branches 5.contractile cells of cardiac muscle tissue 6.atrioventricular (AV) node
3,6,1,4,2,5
Calculate cardiac output if the heart rate is 85 beats/minute, end-diastolic volume (EDV) is 130 ml, and end-systolic volume (ESV) is 60 ml.
5950 ml/min
Calculate the stroke volume (SV) if end-systolic volume (ESV) is 50 ml and the end-diastolic volume (EDV) in a resting heart is 110 ml.
60 ml
Calculate the cardiac output if the heart rate is 100 beats per minute and the stroke volume is 65 ml. -0.65 ml/min -650 ml/min -65 ml/min -6500 ml/min
6500 ml/min
How much blood is pumped from each ventricle during the ventricular ejection phase?
70 ml
Stroke volume averages about: -180 ml per heartbeat. -120 ml per heartbeat. -25 ml per heartbeat. -70 ml per heartbeat.
70 ml per heartbeat.
complex representing ventricular depolarization.
D
interval representing the entire duration of a ventricular action potential.
G
Which of the following volumes should be the greatest? -end-diastolic volume (EDV) -end-systolic volume (ESV) -cardiac output (CO) -stroke volume (SV)
NOT EDV
As ventricular systole begins, all four heart valves are closed during the: -ventricular ejection phase. -ventricular filling phase. -isovolumetric contraction phase. -isovolumetric relaxation phase.
NOT ventricular filling phase NOT isovolumetric relaxation phase
Which wave on the electrocardiogram (ECG) corresponds with the ventricular filling phase of the cardiac cycle? P wave T wave S wave S-T segment
P wave
A damaged atrioventricular (AV) bundle or atrioventricular (AV) node will primarily affect the length of the: T wave. Q-T interval. P wave. P-R interval.
P-R Interval
Which part of the electrocardiogram (ECG) would most be affected by abnormally slow depolarization of the ventricles? QRS wave P wave R-T interval T wave
QRS wave
Which wave on the electrocardiogram (ECG) represents ventricular depolarization? R-R interval T wave P wave QRS wave
QRS wave
On an electrocardiogram (ECG), atrial repolarization is obscured by the: -T wave. -P wave. -S-T segment. -QRS wave.
QRS wave.
What wave on the electrocardiogram (ECG) occurs during the ventricular ejection phase of the cardiac cycle? -R wave -Q wave -T wave -P wave
T wave
Predict the position of the valves during the ventricular ejection phase. -The AV valves are shut while both semilunar valves are forced open. -The AV valves and semilunar valves are shut. -The AV valves are forced open while both semilunar valves are shut. -The AV valves and semilunar valves are forced open.
The AV valves are shut while both semilunar valves are forced open.
What best describes the Frank-Starling law? -The Frank-Starling law states that the more the ventricular muscle cells are stretched, the more forcefully they contract. -The Frank-Starling law states that the greater the stroke volume, the greater the heart rate. -The Frank-Starling law states that the slower the heart rate, the greater the cardiac output. -The Frank-Starling law states that the greater the volume of blood discharged from the heart, the greater the pressure required to discharge the blood.
The Frank-Starling law states that the more the ventricular muscle cells are stretched, the more forcefully they contract.
What activity is occurring in the heart during the Q-T interval on an electrocardiogram (ECG)? -The ventricular cells are undergoing action potentials. -The ventricular cells are repolarizing. -The AV node delay occurs as the action potential spreads from the SA node to the atria to the ventricles. -The atrial cells are undergoing action potentials.
The ventricular cells are undergoing action potentials.
Which of the following is a chronotropic agent that decreases heart rate? -epinephrine -norepinephrine -acetylcholine -glucagon
acetylcholine
The long length of the cardiac action potential, at 200-300 msec, allows for: -a reduction in strength of the heart's contraction. -an opportunity for the heart to fill with blood. -less calcium ions to enter cells. -a faster heart rate.
an opportunity for the heart to fill with blood
What vessel delivers oxygenated blood to systemic capillaries for gas exchange? -aorta -coronary artery -pulmonary trunk -circumflex artery
aorta
Where should the left ventricle send blood? -aorta -pulmonary trunk -left atrium -coronary sinus
aorta
Which vessel supplies the systemic circuit with oxygenated blood? -aorta -superior vena cava -coronary sinus -pulmonary trunk
aorta
The P wave on an electrocardiogram (ECG) represents the depolarization of cells in the: -atrioventricular (AV) node. -ventricles. -atria. -sinoatrial (SA) node.
atria
Which hormone decreases cardiac output by decreasing blood volume and preload? -norepinephrine -atrial natriuretic peptide (ANP) -aldosterone -antidiuretic hormone (ADH)
atrial natriuretic peptide (ANP)
What is NOT part of the cardiac conduction system? -atrioventricular (AV) bundle -atrioventricular (AV) node -sinoatrial sinoatrial (SA) node -atrioventricular (AV) valve
atrioventricular (AV) valve
Which valve is situated between the left atrium and left ventricle? -pulmonary valve -tricuspid valve -aortic valve -bicuspid (mitral) valve
bicuspid (mitral) valve
The coronary sinus does NOT receive blood from the: -middle cardiac vein. -small cardiac vein. -brachiocephalic vein. -great cardiac vein.
brachiocephalic vein.
How do cardiac cells sustain a membrane potential of around 0 mV during the plateau phase? -increased membrane permeability to potassium ions -increased membrane permeability to sodium ions -decrease in the amount of calcium diffusing across the membrane -calcium channels remain open
calcium channels remain open
Autorhythmicity in the heart is the responsibility of: -skeletal muscle cells. -contractile cells. -smooth muscle cells. -cardiac pacemaker cells.
cardiac pacemaker cells
Inotropic agents affect: -heart rate. -contractility. -depolarization. -stroke volume.
contractility
Generally, coronary veins empty into a vessel known as the: -coronary sinus. -inferior vena cava. -aorta. -superior vena cava.
coronary sinus.
The right side of the heart receives: -deoxygenated blood from the systemic circuit. -deoxygenated blood from the pulmonary circuit. -oxygenated blood from the pulmonary circuit. -oxygenated blood from the systemic circuit.
deoxygenated blood from the systemic circuit
What largely determines preload? -end-systolic volume (ESV) -stroke volume -end-diastolic volume (EDV) -afterload
end-diastolic volume (EDV)
The visceral pericardium is the same as the: -endocardium. -myocardium. -epicardium. -fibrous pericardium.
epicardium
Desmosomes present between adjacent cardiac muscle cells allow ions to rapidly pass from one cell to another, permitting communication among cardiac muscle cells. T/F
false
From superficial to deep, the pericardial sac consists of the fibrous pericardium, visceral pericardium, parietal pericardium, and the epicardium. T/F
false
Stroke volume (SV) can be calculated by subtracting the end-diastolic volume (EDV) from the end-systolic volume (ESV). T/F
false
There are two phases of the cardiac cycle in which all four heart valves are open: the isovolumetric contraction phase and the isovolumetric relaxation phase. T/F
false
What is the most superficial layer of the pericardial sac? -epicardium -fibrous pericardium -parietal pericardium -visceral pericardium
fibrous pericardium
Which opening in the interatrial septum of the fetal heart connects the right and left atrium? -foramen ovale -ligamentum arteriosum -ductus arteriosus -fossa ovalis
foramen ovale
The rapid influx of calcium ions into pacemaker cells creates a positive membrane potential inside the cell and is responsible for the: -minimum potential phase. -slow initial repolarization phase. -full depolarization phase. -repolarization phase.
full depolarization phase.
Coronary circulation involves the delivery of oxygenated blood to the: -lungs. -liver. -brain. -heart.
heart
What ion movement changes the membrane potential in a contractile cell from negative to positive during the rapid depolarization phase? -influx of sodium ions -outflow of calcium ions -outflow of potassium ions -influx of calcium ions
influx of sodium ions
What characteristic differentiates cardiac muscle cells from skeletal muscle cells? -intercalated discs -excitability -sarcoplasmic reticulum -striations
intercalated discs
What surface groove separates the right and left ventricles? -interatrial septum -interventricular septum -interventricular sulcus -atrioventricular sulcus
interventricular sulcus
When is the S2 heart sound heard? -isovolumetric contraction phase -ventricular filling -ventricular ejection phase -isovolumetric relaxation phase
isovolumetric relaxation phase
An insufficient mitral valve (bicuspid valve, or left atrioventricular valve) would allow the backflow of blood into the: -left atrium. -right atrium. -left ventricle. -aorta.
left atrium
The apex of the heart is situated toward the: -posterior rib cage. -left hip. -right shoulder. -left shoulder.
left hip
Which chamber experiences a maximum pressure of around 118 mm Hg during contraction? -left ventricle -right ventricle -left atrium -right atrium
left ventricle
The pulmonary circuit involves blood flow from the heart to the: -brain. -lungs. -body. -liver.
lungs
The heart is situated in the middle of the thoracic cavity in a region known as the: -cardiac notch. -dorsal cavity. -mediastinum. -pleural cavity.
mediastinum
What muscles, present in the ventricles, anchor the atrioventricular valves by tendon-like chords called chordae tendineae? -ligamentum arteriosum -pectinate muscles -trabeculae carneae -papillary muscles
papillary muscles
Which of the following is NOT a population of pacemaker cells in the heart? -atrioventricular (AV) node -Purkinje fiber system -sinoatrial (SA) node -papillary muscles
papillary muscles
What is found between the visceral pericardium and the parietal pericardium? -the lungs -pericardial fluid -the heart -fibrous pericardium
pericardial fluid
A contractile cell with a sustained membrane potential of 0 mV is experiencing the: -plateau phase. -repolarization phase. -rapid depolarization phase. -initial repolarization phase.
plateau phase
During what phase of the action potential will calcium ions enter the contractile cell as potassium ions exit? -initial repolarization phase -plateau phase -repolarization phase -rapid depolarization phase
plateau phase
What do pacemaker cell action potentials lack? -repolarization -depolarization -threshold -plateau phase
plateau phase
The degree of stretch experienced by the sarcomeres in the ventricle cells before they contract is called: -preload. -stroke volume. -contractility. -afterload.
preload.
What is the function of the valves in the heart? -promote contraction of the ventricles -eliminate pressure variances within the heart -invert during contraction of the ventricles -prevent backflow of blood through the heart
prevent backflow of blood through the heart
Which vessel is guarded by a semilunar valve at its base? -pulmonary trunk -superior vena cava -coronary sinus -pulmonary vein
pulmonary trunk
Which of the following does NOT return blood to the right atrium of the heart? -pulmonary vein -coronary sinus -inferior vena cava -superior vena cava
pulmonary vein
Which of the following vessels carries oxygenated blood? -superior vena cava -pulmonary artery -pulmonary trunk -pulmonary vein
pulmonary vein
A damaged right bundle branch will prevent the passage of the action potential to the: -atrioventricular (AV) node. -Purkinje fibers in the right ventricle. -sinoatrial (SA) node. -atrioventricular (AV) bundle.
purkinje fibers in the right ventricle
Blood in the right ventricle arrived from the: -right atrium. -bicuspid (mitral) valve. -pulmonary valve. -pulmonary trunk.
right atrium
The right and left atria depolarize and contract following the arrival of the action potential from the: -Purkinje fibers. -atrioventricular (AV) node. -sinoatrial (SA) node. -atrioventricular (AV) bundle.
sinoatrial (SA) node
What normally serves as the pacemaker of the entire heart? -atrioventricular (AV) node -Purkinje fiber system -sinoatrial (SA) node -atrioventricular (AV) bundle
sinoatrial (SA) node
Which of the following pacemaker cell populations has the fastest intrinsic rate of depolarization at about 60-70 times or more per minute? -atrioventricular (AV) node -sinoatrial (SA) node -atrioventricular (AV) bundle -Purkinje fiber system
sintoatrial (SA) node
What two values are needed in order to calculate cardiac output (CO) for a ventricle? -stroke volume (SV) and heart rate (HR) -heart rate (HR) and end-diastolic volume (EDV) -end-diastolic volume (EDV) and end-systolic volume (ESV) -stroke volume (SV) and blood pressure (BP)
stroke volume (SV) and heart rate (HR)
Archie has a resting heart rate of 125 beats per minute. Classify his cardiac dysrhythmia. -heart block -bradycardia -asystole -tachycardia
tachycardia
As a result of the long refractory period in the contractile cell, cardiac muscle can NOT exhibit: -oxygen debt. -treppe. -fatigue. -tetany.
tetany.
Afterload is described as: -the length or degree of stretch of the sarcomeres in the ventricular cells before they contract. -the amount of blood that has drained into the ventricle by the end of the filling phase. -the force the ventricles must overcome to eject blood into their respective arteries. -the ability to generate tension.
the force the ventricles must overcome to eject blood into their respective arteries.
Which two arteries arise from the right coronary artery? -the right anterior interventricular artery and the left posterior interventricular artery -the right anterior interventricular artery and the right circumflex artery -the right marginal artery and the right posterior interventricular artery -the left marginal artery and the right circumflex artery
the right marginal artery and the right posterior interventricular artery
Determine the impact if the connection between the sinoatrial (SA) node and the atrioventricular (AV) node becomes blocked. -The ventricles will contract more quickly. -The atria will contract more forcefully. -The ventricles will contract more slowly. -The ventricular rhythm will not change.
the ventricles will contract more slowly.
What produces the "lub dub" heart sounds? -the sound of blood traveling through the heart -the contraction of the atria, and then the ventricles -the relaxation of the atria, and then the ventricles -the vibrations of the ventricular and blood vessel walls when valves shut
the vibrations of the ventricular and blood vessel walls when valves shut
Pressure in the aorta is greater than pressure in the pulmonary trunk; therefore, the left ventricle has to generate a greater pressure than the right ventricle in order to eject blood from the heart. T/F
true
The right and left coronary arteries receive blood from the: -pulmonary trunk. -superior vena cava. -coronary sinus. -aorta.
aorta.
The amount of blood remaining in each ventricle at the end of the ventricular ejection phase is normally about: -70 ml. -50 ml. -120 ml. -30 ml.
50 ml
wave representing depolarization of all cells within the atria except the SA node.
A
interval that can be used to measure heart rate.
C
