Deck 31: Structure and Function of the Cardiovascular and Lymphatic Systems

Question 1

Which phase of the normal myocardial cell depolarization and repolarization correlates with diastole?

A) Phase 1
B) Phase 2
C) Phase 3
D) Phase 4

Answer 1

Phase 4

Question 2

The significance of the atrial kick is that it affects the contraction of the:

A) Right atria, which is necessary to open the tricuspid valve.
B) Right atria, which is necessary to increase the blood volume from the vena cava.
C) Left atria, which increases the blood volume into the ventricle.
D) Left atria, that is necessary to open the mitral valve.

Answer 2

Left atria, which increases the blood volume into the ventricle.

Question 3

The coronary sinus empties into which cardiac structure?

A) Right atrium
B) Left atrium
C) Superior vena cava
D) Aorta

Answer 3

Right atrium

Question 4

Occlusion of the left anterior descending artery during a myocardial infarction would interrupt blood supply to which structures?

A) Left and right ventricles and much of the interventricular septum
B) Left atrium and the lateral wall of the left ventricle
C) Upper right ventricle, right marginal branch, and right ventricle to the apex
D) Posterior interventricular sulcus and the smaller branches of both ventricles

Question 5

Occlusion of the circumflex artery during a myocardial infarction would interrupt blood supply to which area?

A) Left and right ventricles and much of the interventricular septum
B) Posterior interventricular sulcus and the smaller branches of both ventricles
C) Upper right ventricle, right marginal branch, and right ventricle to the apex
D) Left atrium and the lateral wall of the left ventricle

Question 6

Which event occurs during phase 1 of the normal myocardial cell depolarization and repolarization?

A) Repolarization when potassium moves out of the cells
B) Repolarization when sodium rapidly enters into the cells
C) Early repolarization when sodium slowly enters the cells
D) Early repolarization when calcium slowly enters the cells

Question 7

What is the ratio of coronary capillaries to cardiac muscle cells?

A) 1:1 (one capillary per one muscle cell)
B) 1:2 (one capillary per two muscle cells)
C) 1:4 (one capillary per four muscle cells)
D) 1:10 (one capillary per ten muscle cells)

Question 8

During the cardiac cycle,which structure directly delivers action potential to the ventricular myocardium?

A) Sinoatrial (SA) node
B) Atrioventricular (AV) node
C) Purkinje fibers
D) Bundle branches

Question 9

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 innervation via the vagus nerve.
D) Depolarizes more rapidly than other automatic cells of the heart.

Question 10

Which chamber of the heart endures the highest pressures?

A) Right atrium
B) Left atrium
C) Left ventricle
D) Right ventricle

Question 11

What period follows depolarization of the myocardium and represents a period during which no new cardiac potential can be propagated?

A) Refractory
B) Hyperpolarization
C) Threshold
D) Sinoatrial (SA)

Question 12

The coronary ostia are located in the:

A) Left ventricle
B) Aortic valve
C) Coronary sinus
D) Aorta

Question 13

What is the process that ensures mitral and tricuspid valve closure after the ventricles are filled with blood?

A) Chordae tendineae relax, which allows the valves to close.
B) Increased pressure in the ventricles pushes the valves to close.
C) Trabeculae carneae contract, which pulls the valves closed.
D) Reduced pressure in the atria creates a negative pressure that pulls the valves closed.

Question 14

Which statement does not accurately describe the pericardium?

A) The pericardium is a double-walled membranous sac that encloses the heart.
B) It is made up of connective tissue and a surface layer of squamous cells.
C) The pericardium protects the heart against infection and inflammation from the lungs and pleural space.
D) It contains pain and mechanoreceptors that can elicit reflex changes in blood pressure and heart rate.

Question 15

Which cardiac chamber has the thinnest wall and why?

A) The right and left atria; they are low-pressure chambers that serve as storage units and conduits for blood.
B) The right and left atria; they are not directly involved in the preload, contractility, or afterload of the heart.
C) The left ventricle; the mean pressure of blood coming into this ventricle is from the lung, which has a low pressure.
D) The right ventricle; it pumps blood into the pulmonary capillaries, which have a lower pressure compared with the systemic circulation.

Question 16

During the cardiac cycle,why do the aortic and pulmonic valves close after the ventricles relax?

A) Papillary muscles relax, which allows the valves to close.
B) Chordae tendineae contract, which pulls the valves closed.
C) Reduced pressure in the ventricles creates a negative pressure, which pulls the valves closed.
D) Blood fills the cusps of the valves and causes the edges to merge, closing the valves.

Question 17

Oxygenated blood flows through which vessel?

A) Superior vena cava
B) Pulmonary veins
C) Pulmonary artery
D) Coronary veins

Question 18

Regarding the heart's valves,what is a function of the papillary muscles?

A) The papillary muscles close the semilunar valve.
B) These muscles prevent backward expulsion of the atrioventricular valve.
C) They close the atrioventricular valve.
D) The papillary muscles open the semilunar valve.

Question 19

In the normal electrocardiogram,what does the PR interval represent?

A) Atrial depolarization
B) Ventricular depolarization
C) Atrial activation to onset of ventricular activity
D) Electrical systole of the ventricles

Question 20

What causes depolarization of a cardiac muscle cell to occur?

A) Decrease in the permeability of the cell membrane to potassium
B) Rapid movement of sodium into the cell
C) Decrease in the movement of sodium out of the cell
D) Rapid movement of calcium out of the cell

Question 21

Within a physiologic range,what does an increase in left ventricular end-diastolic volume (preload)result in?

A) Increase in force of contraction
B) Decrease in refractory time
C) Increase in afterload
D) Decrease in repolarization

Question 22

Where is the major cardiovascular center in the central nervous system?

A) Frontal lobe
B) Thalamus
C) Brainstem
D) Hypothalamus

Question 23

What is the most important negative inotropic agent?

A) Norepinephrine
B) Epinephrine
C) Acetylcholine
D) Dopamine

Question 24

What is the major determinant of the resistance that blood encounters as it flows through the systemic circulation?

A) Volume of blood in the systemic circulation
B) Muscle layer of the metarterioles
C) Muscle layer of the arterioles
D) Force of ventricular contraction

Question 25

If the sinoatrial (SA)node fails,then at what rate (depolarizations per minute)can the atrioventricular (AV)node depolarize?

A) 60 to 70
B) 40 to 60
C) 30 to 40
D) 10 to 20

Question 26

Pressure in the left ventricle must exceed pressure in which structure before the left ventricle can eject blood?

A) Superior vena cava
B) Aorta
C) Inferior vena cava
D) Pulmonary veins

Question 27

Where in the heart are the receptors for neurotransmitters located?

A) Semilunar and atrioventricular (AV) valves
B) Endocardium and sinoatrial (SA) node
C) Myocardium and coronary vessels
D) Epicardium and AV node

Question 28

Which complex (wave)represents the sum of all ventricular muscle cell depolarizations?

A) PRS
B) QRS
C) QT interval
D) P

Question 29

What is an expected change in the cardiovascular system that occurs with aging?

A) Arterial stiffening
B) Decreased left ventricular wall tension
C) Decreased aortic wall thickness
D) Arteriosclerosis

Question 30

What enables electrical impulses to travel in a continuous cell-to-cell fashion in myocardial cells?

A) Sarcolemma sclerotic plaques
B) Intercalated disks
C) Trabeculae carneae
D) Bachmann bundles

Question 31

After the baroreceptor reflex is stimulated,the resulting impulse is transmitted from the carotid artery by which sequence of events?

A) Vagus nerve to the medulla to increase parasympathetic activity and to decrease sympathetic activity
B) Glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase sympathetic activity and to decrease parasympathetic activity
C) Glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase parasympathetic activity and to decrease sympathetic activity
D) Glossopharyngeal cranial nerve through the vagus nerve to the hypothalamus to increase parasympathetic activity and to decrease sympathetic activity

Question 32

The Bainbridge reflex is thought to be initiated by sensory neurons in which cardiac location?

A) Atria
B) Aorta
C) Sinoatrial (SA) node
D) Ventricles

Question 33

The right lymphatic duct drains into which structure?

A) Right subclavian artery
B) Right atrium
C) Right subclavian vein
D) Superior vena cava

Question 34

Reflex control of total cardiac output and total peripheral resistance is controlled by what mechanism?

A) Parasympathetic stimulation of the heart, arterioles, and veins
B) Sympathetic stimulation of the heart, arterioles, and veins
C) Autonomic control of the heart only
D) Somatic control of the heart, arterioles, and veins

Question 35

As stated in the Frank-Starling law,a direct relationship exists between the _____ of the blood in the heart at the end of diastole and the _____ of contraction during the next systole.

A) Pressure; force
B) Volume; strength
C) Viscosity; force
D) Viscosity; strength

Question 36

What can shorten the conduction time of action potential through the atrioventricular (AV)node?

A) Parasympathetic nervous system
B) Catecholamines
C) Vagal stimulation
D) Sinoatrial node (SA)

Question 37

The resting heart rate in a healthy person is primarily under the control of which nervous system?

A) Sympathetic
B) Parasympathetic
C) Somatic
D) Spinal

Question 38

What is the effect of epinephrine on b₃ receptors on the heart?

A) Decreases coronary blood flow.
B) Supplements the effects of both b1 and b2 receptors.
C) Increases the strength of myocardial contraction.
D) Prevents overstimulation of the heart by the sympathetic nervous system.

Question 39

Continuous increases in left ventricular filing pressures result in which disorder?

A) Mitral regurgitation
B) Mitral stenosis
C) Pulmonary edema
D) Jugular vein distention

Question 40

When the volume of blood in the ventricle at the end of diastole increases,the force of the myocardial contraction during the next systole will also increase,which is an example of which law or theory about the heart?

A) Laplace's law
B) Poiseuille law
C) Cross-bridge theory
D) Frank-Starling law

Question 41

Which statements are true concerning the method in which substances pass between capillaries and the interstitial fluid? (Select all that apply.)

A) Substances pass through junctions between endothelial cells.
B) Substances pass through pores or oval windows (fenestrations).
C) Substances pass between vesicles by active transport across the endothelial cell membrane.
D) Substances pass across the endothelial cell membrane by osmosis.
E) Substances pass through endothelial cell membranes by diffusion.

Question 42

Which intracardiac pressure is generated by the atrial contraction?

A) A wave
B) C wave
C) Y descent
D) X descent

Question 43

What physical sign is the result of turbulent blood flow through a vessel?

A) Increased blood pressure during periods of stress
B) Bounding pulse felt on palpation
C) Cyanosis observed on excretion
D) Murmur heard on auscultation

Question 44

Match the description with the corresponding terms.
Cross-bridge theory

A)Relationship among blood flow, pressure, and resistance
B)Increased heart rate from increased volume
C)Relationship of wall tension, intraventricular pressure, internal radius, and wall thickness
D)Cycles of attachment, movement, and dissociation of thin filaments during the attachments of actin to myosin
E)Length-tension relationship of cardiac muscle

Question 45

Match the description with the corresponding terms.
Frank-Starling law

A)Relationship among blood flow, pressure, and resistance
B)Increased heart rate from increased volume
C)Relationship of wall tension, intraventricular pressure, internal radius, and wall thickness
D)Cycles of attachment, movement, and dissociation of thin filaments during the attachments of actin to myosin
E)Length-tension relationship of cardiac muscle

Question 46

What is the major effect of a calcium channel blocker such as verapamil on cardiac contractions?

A) Increases the rate of cardiac contractions.
B) Decreases the strength of cardiac contractions.
C) Stabilizes the rhythm of cardiac contractions.
D) Stabilizes the vasodilation during cardiac contractions.

Question 47

Which intracardiac pressure is produced because of the descent of the tricuspid valve ring and by the ejection of blood from both ventricles?

A) V wave
B) C wave
C) Y descent
D) X descent

Question 48

Which function of the cardiovascular system is often affected by ischemia?

A) Cardiac output (CO)
B) Stroke volume (SV)
C) Heart rate (HR)
D) Cardiac index (CI)

Question 49

An early diastole peak caused by filling of the atrium from peripheral veins is identified by which intracardiac pressure?

A) A wave
B) V wave
C) C wave
D) X descent

Question 50

Match the description with the corresponding terms.
Laplace's law

A)Relationship among blood flow, pressure, and resistance
B)Increased heart rate from increased volume
C)Relationship of wall tension, intraventricular pressure, internal radius, and wall thickness
D)Cycles of attachment, movement, and dissociation of thin filaments during the attachments of actin to myosin
E)Length-tension relationship of cardiac muscle

Question 51

Match the description with the corresponding terms.
Bainbridge reflex

A)Relationship among blood flow, pressure, and resistance
B)Increased heart rate from increased volume
C)Relationship of wall tension, intraventricular pressure, internal radius, and wall thickness
D)Cycles of attachment, movement, and dissociation of thin filaments during the attachments of actin to myosin
E)Length-tension relationship of cardiac muscle

Question 52

Match the description with the corresponding terms.
Poiseuille law

A)Relationship among blood flow, pressure, and resistance
B)Increased heart rate from increased volume
C)Relationship of wall tension, intraventricular pressure, internal radius, and wall thickness
D)Cycles of attachment, movement, and dissociation of thin filaments during the attachments of actin to myosin
E)Length-tension relationship of cardiac muscle