Deck 19: The Circulatory System: Heart

Question 1

Ventricular pressure increases the fastest during ventricular filling.

Answer 1

False

Question 2

Papillary muscles prevent the AV valves from prolapsing (bulging) excessively into the atria when the
ventricles contract.

Answer 2

True

Question 3

The fibrous skeleton of the heart serves as electrical insulation between the atria and the
ventricles.

Answer 3

True

Question 4

Blood in the heart chambers provides most of the myocardium's oxygen and nutrient needs.

Question 5

carry oxygen-poor blood.

A)Pulmonary veins and vena cavae
B)Aorta and pulmonary veins
C)Aorta and vena cavae
D)Venae cavae and pulmonary arteries
E)Pulmonary veins and pulmonary arteries

Question 6

The tricuspid valve regulates the opening between

A)the right atrium and the left atrium.
B)the right atrium and right ventricle.
C)the right atrium and the left ventricle.
D)the left atrium and the left ventricle.
E)the left ventricle and the right ventricle.

Question 7

is the most superficial layer enclosing the heart.

A)Parietal pericardium
B)Visceral pericardium
C)Endocardium
D)Epicardium
E)Myocardium

Question 8

Atrial hypertrophy would probably cause an enlarged P wave on an electrocardiogram.

Question 9

Desmosomes form channels that allow each cardiocyte to electrically stimulate its neighbors.

Question 10

The ventricles are almost empty at the end of ventricular diastole.

Question 11

Parasympathetic stimulation reduces heart rate.

Question 12

The performs the work of the heart.

A)fibrous skeleton
B)pericardial cavity
C)endocardium
D)myocardium
E)epicardium

Question 13

Repolarization of a ventricular cardiocyte takes longer than repolarization of a typical neuron.

Question 14

Cardiac muscle can only use glucose as a source of organic fuel.

Question 15

The pulmonary circuit is supplied by both the right and the left sides of the heart.

Question 16

Hypercapnia and acidosis have positive chronotropic effects.

Question 17

belong to the pulmonary circuit.

A)Aorta and venae cavae
B)Aorta and pulmonary veins
C)Pulmonary arteries and venae cavae
D)Venae cavae and pulmonary veins
E)Pulmonary arteries and pulmonary veins

Question 18

If the SA node is damaged, nodal rhythm is sufficient to sustain life.

Question 19

The systemic circuit contains oxygen-rich blood only.

Question 20

Endurance athletes commonly have a resting heart rate as low as 40 bpm, and a stroke volume as low
as 50 mL/beat.

Question 21

This figure shows the internal anatomy of the heart.What blood vessels carry blood to the lungs?

A)only 3 and 5
B)only 6, 7, and 2
C)only 4, 6, and 8
D)only 1 and 6
E)only 3, 5, and 6

Question 22

This figure shows the internal anatomy of the heart.What does "2" represent?

A)the right atrioventricular (AV) (tricuspid) valve
B)the left atrioventricular (AV) (bicuspid) valve
C)the aortic valve
D)the pulmonary valve
E)the interventricular septum

Question 23

The plateau in the action potential of cardiac muscle results from the action of

A)Na+ inflow.
B)K+ inflow.
C)K+ outflow.
D)fast Ca₂+ channels.
E)slow Ca₂+ channels.

Question 24

This figure shows the internal anatomy of the heart.What does "4" represent?

A)a papillary muscle
B)pectinate muscles
C)tendinous cords
D)the interventricular septum
E)the interatrial septum

Question 25

Obstruction of the will cause a more severe myocardial infarction (MI) than the obstruction of any of the others.

A)left marginal vein
B)left coronary artery (LCA)
C)posterior interventricular vein
D)anterior interventricular branch
E)circumflex branch

Question 26

The pacemaker potential is a result of

A)Na+ inflow.
B)Na+ outflow.
C)K+ inflow.
D)K+ outflow.
E)Ca₂+ inflow.

Question 27

Opening and closing of the heart valves is caused by

A)breathing.
B)gravity.
C)valves contracting and relaxing.
D)osmotic gradients.
E)pressure gradients.

Question 28

This figure shows an action potential in a ventricular cardiocyte.indicates when sodium channels are fully open.

A)1
B)3
C)2
D)5
E)4

Question 29

This figure shows the internal anatomy of the heart.What blood vessel(s) receive(s) blood from the right ventricle?

A)8
B)3 and 5
C)4 and 8
D)1
E)2 and 7

Question 30

Oxygen-poor blood passes through

A)the right AV (tricuspid) valve and pulmonary valve.
B)the right AV (tricuspid) valve only.
C)the left AV (bicuspid) valve and aortic valve.
D)the left AV (bicuspid) valve only.
E)the pulmonary and aortic valves.

Question 31

These are features of cardiac muscle fibers except

A)they depend almost exclusively on aerobic respiration.
B)they are rich in glycogen.
C)they have huge mitochondria.
D)they are very rich in myoglobin.
E)they have about the same endurance as skeletal muscle fibers.

Question 32

Any abnormal cardiac rhythm is called a(n)

A)ectopic focus.
B)sinus rhythm.
C)nodal rhythm.
D)heart block.
E)arrhythmia.

Question 33

This figure shows the principal coronary blood vessels.Which one is the left coronary artery (LCA)?

A)11
B)8
C)5
D)3
E)1

Question 34

Cardiac muscle shares this feature with skeletal muscle.

A)cardiac muscle fibers have striations
B)all cardiac muscle fibers depend on nervous stimulation
C)cardiac muscle fibers communicate by electrical (gap) junctions
D)cardiac muscle fibers are joined end to end by intercalated discs
E)some cardiac muscle fibers are autorhythmic

Question 35

The is the pacemaker that initiates each heart beat.

A)sympathetic division of the nervous system
B)autonomic nervous system
C)sinoatrial (SA) node
D)atrioventricular (AV) node
E)cardiac conduction system

Question 36

This figure shows electrical activity of the SA node.indicate(s) when calcium enters the myocytes.

A)1 and 2
B)2 and 3
C)3
D)2
E)1

Question 37

Cells of the sinoatrial node during the pacemaker potential.

A)depolarize fast
B)depolarize slow
C)repolarize slow
D)repolarize fast
E)depolarize slow and repolarize fast

Question 38

This is the correct path of an electrical excitation from the pacemaker to a cardiocyte in the left ventricle (LV).

A)sinoatrial (SA) node → atrioventricular (AV) bundle → atrioventricular (AV) node → Purkinje fibers → cardiocyte in LV
B)atrioventricular (AV) node → Purkinje fibers → atrioventricular (AV) bundle → sinoatrial (SA) node → cardiocyte in LV
C)atrioventricular (AV) node → sinoatrial (SA) node → atrioventricular (AV) bundle → Purkinje fibers → cardiocyte in LV
D)sinoatrial (SA) node → atrioventricular (AV) node → atrioventricular (AV) bundle → Purkinje fibers → cardiocyte in LV
E)sinoatrial (SA) node → atrioventricular (AV) node → Purkinje fibers → atrioventricular (AV) bundle → cardiocyte in LV

Question 39

After entering the right atrium, the furthest a red blood cell can travel is the

A)right ventricle.
B)pulmonary trunk.
C)superior vena cava.
D)ascending aorta.
E)left atrium.

Question 40

Which of these is not part of the cardiac conduction system?

A)the sinoatrial (SA) node
B)the tendinous cords (TC)
C)the atrioventricular (AV) node
D)the atrioventricular (AV) bundle (bundle of His)
E)the Purkinje fibers

Question 41

This is the correct sequence of events of the cardiac cycle.

A)ventricular filling → isovolumetric contraction → isovolumetric relaxation → ventricular ejection
B)ventricular filling → isovolumetric relaxation → isovolumetric contraction → ventricular ejection
C)ventricular filling → ventricular ejection → isovolumetric contraction → isovolumetric relaxation
D)ventricular filling → isovolumetric relaxation → ventricular ejection → isovolumetric contraction
E)ventricular filling → isovolumetric contraction → ventricular ejection → isovolumetric relaxation

Question 42

This figure shows a normal electrocardiogram.Two or more consecutive waves at point "1" might suggest

A)sinus rhythm.
B)nodal rhythm.
C)ventricular fibrillation.
D)premature ventricular contraction (PVC).
E)heart block.

Question 43

Assume that the left ventricle of a child's heart has an EDV=90mL, and ESV=60mL, and a cardiac output of 2,400 mL/min.His SV and HR are

A)SV=30 mL/beat, HR=80 bpm.
B)SV=40 mL/beat, HR=60 bpm.
C)SV=80 mL/beat, HR=30 bpm.
D)SV=150 mL/beat, HR=16 bpm.
E)SV=16 mL/beat, HR=150 bpm.

Question 44

This figure shows a normal electrocardiogram.Missing of waves at point might indicate SA node damage.

A)1
B)2
C)3
D)4
E)5

Question 45

Mitral valve stenosis causes blood to leak back into the when the ventricles contract.

A)left atrium
B)right atrium
C)aorta
D)pulmonary trunk
E)pulmonary arteries

Question 46

Congestive heart failure (CHF) of the right ventricle

A)can cause pulmonary edema.
B)can cause systemic edema.
C)increases the ejection fraction of the right ventricle.
D)reduces the ejection fraction of the left ventricle.
E)increases cardiac output in both ventricles.

Question 47

Most of the ventricle filling occurs

A)during atrial systole.
B)when the AV valve is closed.
C)during ventricular systole.
D)during atrial diastole.
E)during isovolumetric contraction.

Question 48

Mitral valve prolapse (MVP) generates a murmur associated with the heart sound that occurs when the .

A)lubb (S1); atria contract
B)dupp (S2); atria relax
C)lubb (S1); ventricles contract
D)dupp (S2); ventricles relax
E)lubb (S1); ventricles relax

Question 49

This figure shows a normal electrocardiogram.The deflection at point(s) is generated by ventricular repolarization and it is called the .

A)3; R wave
B)4, 2, and 5; QRS wave
C)1; P wave
D)5; P wave
E)3; T wave

Question 50

The provides most of the Ca₂+ needed for myocardial contraction.

A)extracellular fluid
B)mitochondria
C)sarcoplasmic reticulum
D)Golgi apparatus
E)cytoskeleton

Question 51

The long absolute refractory period of cardiocytes

A)ensures a short twitch.
B)prevents tetanus.
C)makes the heart prone to arrhythmias.
D)prevents the occurrence of ectopic focuses.
E)causes the pacemaker potential.

Question 52

Atrial depolarization causes

A)the P wave.
B)the QRS complex.
C)the T wave.
D)the first heart sound.
E)the quiescent period.

Question 53

The long plateau in the action potential observed in cardiocytes is probably related with staying longer in their cytosol.

A)Na+
B)K+
C)Ca₂+
D)Cl-
E)Na+, K+, and Ca₂+

Question 54

If the sinoatrial (SA) is damaged, the heart will likely beat at

A)less than 10 bpm.
B)10 to 20 bpm.
C)20 to 40 bpm.
D)40 to 50 bpm.
E)70 to 80 bpm.

Question 55

This figure shows the events of the cardiac cycle.At 0.2 sec in the graph .

A)the aortic valve is open
B)the AV valve is open
C)the ventricles have reached end-diastolic volume
D)the ventricles are in the isovolumetric phase
E)the ventricles are in systole

Question 56

Isovolumetric contraction occurs during the of the electrocardiogram.

A)P wave
B)P-Q segment
C)R wave
D)S-T segment
E)T wave

Question 57

Atrial systole begins

A)immediately before the P wave.
B)immediately after the P wave.
C)during the Q wave.
D)during the S-T segment.
E)immediately after the T wave.

Question 58

This figure shows the events of the cardiac cycle.What does "4" represent?

A)aortic valve opening
B)aortic valve closing
C)AV valve opening
D)AV valve closing
E)both aortic and AV valves opening

Question 59

When the left ventricle contracts, the valve closes and the valve is pushed open.

A)bicuspid; pulmonary
B)tricuspid; pulmonary
C)tricuspid; aortic
D)mitral; aortic
E)aortic; pulmonary

Question 60

During isovolumetric contraction, the pressure in the ventricles

A)falls rapidly.
B)rises rapidly.
C)remains constant.
D)rises and then falls.
E)falls and then rises.

Question 61

The volume of blood ejected by each ventricle in one minute is called

A)the cardiac reserve.
B)the preload.
C)the afterload.
D)the stroke volume.
E)the cardiac output.

Question 62

increase(s) stroke volume.

A)High arterial blood pressure
B)Negative inotropic agents
C)Increased venous return
D)Increased afterload
E)Dehydration

Question 63

The Frank-Starling law of the heart states that stroke volume is proportional to

A)the end-systolic volume.
B)the end-diastolic volume.
C)the afterload.
D)the heart rate.
E)contractility.

Question 64

Cardioinhibitory centers in the receive input from .

A)cortex; proprioceptors in the muscles
B)thalamus; chemoreceptors in the medulla oblongata
C)hypothalamus; proprioceptors in the joints
D)medulla oblongata; chemoreceptors in the aortic arch
E)pons; baroreceptors in the internal carotid