Deck 19: Cardiovascular System: Heart

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Question
Which heart chambers contain deoxygenated blood?

A) Left atrium and right atrium
B) Left ventricle and right ventricle
C) Right atrium and right ventricle
D) Left atrium and left ventricle
E) Right atrium and left ventricle
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Question
Which layer is made of dense irregular connective tissue?

A) Myocardium
B) Fibrous pericardium
C) Epicardium
D) Serous pericardium
E) Endocardium
Question
The inferior, conical end of the heart is called the ________.
Question
Arteries carry blood toward the heart, while veins carry blood away from the heart.
Question
Which pair is located more anteriorly in a heart in normal position?

A) Left atrium and left ventricle
B) Left atrium and right ventricle
C) Right atrium and left atrium
D) Right atrium and right ventricle
E) Right atrium and left ventricle
Question
The units for perfusion of blood are typically

A) grams per minute.
B) milliliters per minute per gram.
C) milliliters per hour per kilogram.
D) liters per gram.
E) beats per minute per gram.
Question
The serous fluid within the pericardial cavity works to

A) lubricate membranes of the pericardium.
B) slow the heart rate.
C) equalize the pressure in the great vessels.
D) eliminate blood pressure spikes.
E) All of the choices are correct.
Question
The term "epicardium" is another name for the

A) visceral layer of the serosal pericardium.
B) parietal layer of the serosal pericardium.
C) external layer of the fibrous pericardium.
D) myocardium.
E) mediastinum.
Question
Which circuit of the cardiovascular system includes the left ventricle and aorta?

A) Pulmonary circuit
B) Cardio circuit
C) Coronary circuit
D) Systemic circuit
Question
Occlusion of blood vessels tends to lead to

A) increases in perfusion.
B) increases in capillary exchange.
C) inadequate blood supply and damage to body tissues.
D) defibrillation of cardiac muscle cell contraction.
Question
Which can be used to characterize blood flow in the human body?
A: There is a unidirectional blood flow.
B: Arteries always carry oxygenated blood.
C: Veins always carry deoxygenated blood.
D: Arteries carry blood away from the heart.
E: Veins carry blood toward the heart.

A) a, c, d, e
B) a, b, c, d, e
C) a, d, e
D) b, c, d, e
E) d, e
Question
The pericardial cavity is between the

A) heart muscle and serous pericardium.
B) fibrous and serous layers of the pericardium.
C) visceral and parietal layers of the serous pericardium.
D) parietal and myocardial layers of the fibrous pericardium.
Question
The main functions of the cardiovascular system include the transport and exchange of respiratory gases, nutrients, and wastes throughout the body.
Question
Which circuit of the cardiovascular system is responsible for sending blood to the kidneys, stomach, and pelvic regions?

A) Pulmonary circuit
B) Visceral circuit
C) Coronary circuit
D) Systemic circuit
Question
Which correctly describes the heart's apex?

A) Projects slightly anteroinferiorly toward the left side of the body
B) Projects slightly anteroinferiorly toward the right side of the body
C) Projects slightly posteroinferiorly toward the left side of the body
D) Projects slightly posteroinferiorly toward the right side of the body
E) Projects slightly posteroinferiorly toward the midline of the body
Question
The receiving chambers of the heart are the atria, and the forcefully pumping chambers of the heart are the ventricles.
Question
Which of the cardiovascular system's circuits has deoxygenated blood in its arteries?

A) Pulmonary circuit
B) Visceral circuit
C) Coronary circuit
D) Systemic circuit
Question
The base of the heart faces in the ________ directions.

A) anterior and inferior
B) anterior and superior
C) posterior and superior
D) posterior and inferior
E) None of these choices is correct.
Question
Which carries oxygenated blood from the lungs to the heart?

A) Pulmonary arteries
B) Pulmonary veins
C) Pulmonary trunk
D) Inferior vena cava
E) Superior vena cava
Question
The pulmonary trunk receives blood from the right ventricle and conducts it toward the lung. The pulmonary trunk is a(n)

A) artery.
B) capillary.
C) vein.
Question
The pericardium helps prevent overfilling of the heart and it lessens the friction of movements during heartbeats.
Question
Metabolically, cardiac muscle relies on

A) aerobic metabolism using glycolysis of glycogen to meet most ATP demands.
B) aerobic metabolism using many mitochondria and a rich supply of myoglobin.
C) anaerobic metabolism using glycolytic enzymes to quickly generate ATP.
D) anaerobic metabolism using myoglobin, creatin kinase, and ketone bodies.
Question
Myofibrils within cardiac muscle cells are aligned in sarcomeres.
Question
Deep to the interventricular sulci is the thick muscular wall that divides the left and right ventricles, known as the interventricular ________.
Question
Contrast the length-tension relationship for cardiac muscle to that which is found in skeletal muscle. In other words, for each type of muscle, what is the optimal length? How is such an arrangement adaptive to cardiac muscle?
Question
Which feature permits the compression necessary to pump large volumes of blood out of the ventricles?

A) Negative pressure inside the ventricles
B) Absence of oxygenated blood in the atria
C) Arrangement of cardiac muscle in the heart wall
D) Presence of skeletal muscle tissue in the heart skeleton
E) Presence of papillary muscles in the ventricles
Question
Which describes the endocardium?
A: Has single layer of epithelium
B: Has layer of areolar connective tissue
C: Epithelial cells are squamous
D: Epithelial cells are cuboidal
E: Has layer of adipose connective tissue
F: Has patches of myocardium

A) a, b, c
B) a, b, d
C) a, d, e
D) a, b, c, e
E) a, e, f
Question
The papillary muscles attach to the cusps of the atrioventricular valves by means of the

A) pectinate muscles.
B) trabeculae carneae.
C) conus arteriosus.
D) tendinous cords.
E) tricuspid valve.
Question
Each of the receiving chambers of the heart has a wrinkled flaplike extension; the one that is more visible from an anterior view is the

A) interatrial septum.
B) interventricular septum.
C) left auricle.
D) right auricle.
Question
What are the cell-to-cell contacts of the cardiac muscle fibers called?

A) Z discs
B) T-tubules
C) Intercalated discs
D) Cardiac discs
E) Sarcoplasmic reticulum
Question
The atria are separated from the ventricles externally by the

A) anterior interventricular sulcus.
B) posterior interventricular sulcus.
C) sinoventricular sulcus.
D) coronary sulcus.
E) None of the choices is correct.
Question
Which are functions performed by the fibrous skeleton of the heart?
A: Separates the atria and ventricles
B: Anchors the heart valves
C: Provides electrical insulation between the atria and ventricles
D: Provides the framework for the attachment of the myocardium
E: None of these are true functions of the fibrous skeleton of the heart

A) a, d
B) b, d
C) a, c, d
D) a, b, c, d
E) e
Question
Which are differences between cardiac muscle tissue and skeletal muscle tissue?
A: The sarcoplasmic reticulum in cardiac muscle is less extensive.
B: The sarcoplasmic reticulum in cardiac muscle is more organized.
C: Cardiac muscle has intercalated discs; skeletal muscle does not.
D: Cardiac muscle has 1 or 2 nuclei per cell; skeletal muscle has multiple nuclei per cell.
E: Cardiac muscle has more well-defined terminal cisternae.

A) a, c, d
B) a, c, e
C) b, c, e
D) a, b, e
E) b, d, e
Question
The metabolic pathways of cardiac muscle make it

A) somewhat susceptible to heart attack, because it relies so exclusively on aerobic metabolism.
B) extremely susceptible to heart attack, because it uses such a variety of fuel sources.
C) somewhat susceptible to heart attack, because it has so few mitochondria.
D) relatively resistant to heart attack, because it uses exclusively anaerobic metabolism.
E) relatively resistant to heart attack, because it has a great capacity to accrue oxygen debt.
Question
The layer of the heart wall composed of cardiac muscle tissue is the

A) pericardium.
B) myocardium.
C) endocardium.
D) pericardial cavity.
E) pectinate muscle.
Question
Pectinate muscles are found on the

A) posterior wall of the right ventricle.
B) anterior wall of the right ventricle.
C) internal walls of the right and left atria.
D) posterior walls of the right and left ventricles.
E) external wall of the right atrium.
Question
The posterior interventricular sulcus

A) is another name for the coronary sulcus.
B) contains the great cardiac vein and coronary sinus.
C) is a groove between the ventricles on the back of the heart.
D) is a valve in the interventricular septum that closes at birth.
Question
The fossa ovalis appears just above the opening of the coronary sinus within the

A) left atrium.
B) left ventricle.
C) right atrium.
D) right ventricle.
Question
From which view is the connection between the pulmonary veins and the heart most visible?

A) Anterior view
B) Posterior view
Question
The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges called

A) conus arteriosus.
B) atrioventricular opening.
C) trabeculae carneae.
D) tendinous cords.
E) pectinate muscles.
Question
The heart valves

A) stabilize and hold the arteries leaving the heart.
B) permit the passage of blood in one direction.
C) separate the right and left sides of the heart.
D) are only used in the fetal heart.
E) direct the conduction impulse through the heart muscle.
Question
SA nodal cells are autorhythmic.
Question
Once an SA nodal cell reaches threshold, the depolarization phase occurs during which

A) potassium comes in through fast voltage-gated channels.
B) calcium comes in through fast voltage-gated channels.
C) potassium moves out through fast voltage-gated channels.
D) sodium moves out through slow voltage-gated channels.
E) calcium moves out through slow voltage-gated channels.
Question
Cardiac muscle is able to use a variety of fuel types for cellular respiration.
Question
Which valve prevents the backflow of blood into the left ventricle when the ventricles relax?

A) Left atrioventricular valve
B) Aortic semilunar valve
C) Right atrioventricular valve
D) Pulmonary semilunar valve
E) None of the choices is correct.
Question
During the plateau phase of a cardiac muscle cell's action potential, the membrane stays

A) depolarized as potassium exits and calcium enters.
B) depolarized as potassium enters and calcium exits.
C) repolarized as sodium enters and calcium exits.
D) hyperpolarized as sodium and calcium exit.
E) hyperpolarized as potassium enters and calcium exits.
Question
Typically, there are ________ papillary muscles that project from the wall of the left ventricle and attach to the tendinous cords that support the left AV valve.

A) three
B) two
C) a highly variable number of
D) six
E) no
Question
As with action potentials in other types of cells, the repolarization of cardiac muscle cells involves the

A) entrance of calcium through voltage-gated channels.
B) exit of potassium through voltage-gated channels.
C) entrance of sodium through voltage-gated channels.
D) binding of ACh to ACh receptor.
E) simultaneous closure of sodium channels and opening of calcium channels.
Question
At the AV node of the conduction system, the action potential is

A) rapidly advanced due to the cells being large and well connected by gap junctions.
B) rapidly advanced due to the cells being small and well insulated by myelin.
C) delayed due to the cells being small and having few gap junctions.
D) delayed due to the cells being large and having many leakage channels.
Question
The hearts nodal cells have a more negative resting potential than neurons do, because nodal cells lack leak channels for sodium and potassium ions.
Question
The membrane of a contractile cardiac muscle cell contains

A) no calcium pumps.
B) calcium pumps that move calcium out of the cell.
C) calcium pumps that move calcium into the cell.
D) calcium pumps that open and allow calcium to diffuse down its concentration gradient to reach equilibrium.
Question
The membrane of a contractile cardiac muscle cell contains

A) fast voltage-gated sodium channels and fast voltage-gated calcium channels.
B) fast voltage-gated sodium channels and slow voltage-gated calcium channels.
C) slow voltage-gated sodium channels and slow voltage-gated calcium channels.
D) slow voltage-gated sodium channels and fast voltage-gated calcium channels.
Question
Vagal tone refers to the

A) decreasing of the heart rate below its inherent rhythm by parasympathetic stimulation.
B) decreasing of the heart rate below its inherent rhythm by sympathetic stimulation.
C) increasing of the heart rate above its inherent rhythm by sympathetic stimulation.
D) increasing of the heart rate above its inherent rhythm by parasympathetic stimulation.
Question
As blood is pumped out of the heart and into the major arteries leaving the heart, it

A) pushes against the semilunar valves and opens them.
B) pushes against the semilunar valves and closes them.
C) fills the cusps of the semilunar valves, causing them to expand and block the backflow of blood
D) pushes against the atrioventricular valves and opens them.
E) fills the cusps of the atrioventricular valve causing opening of the bicuspid and closure of the tricuspid.
Question
How many half-moon shaped, pocketlike cusps are found in each semilunar valve?

A) 1
B) 2
C) 3
D) 4
E) 6
Question
Nodal cells contain fast voltage-gated calcium channels.
Question
What is the sequence of events in the transmission of an impulse through the heart muscle?
A: AV node
B: AV bundle
C: SA node
D: Through the atria
E: Through the ventricles
F: Bundle branches
G: Purkinje fibers

A) c, d, a, b, f, g, e
B) d, b, a, c, f, g, e
C) b, a, d, c, f, g, e
D) f, g, d, c, b, a, e
E) c, d, a, f, b, g, e
Question
Which action leads to the closure of the right atrioventricular valve?

A) Contraction of the right atrium
B) Contraction of the left atrium
C) Contraction of the right ventricle
D) Relaxation of the right ventricle
E) Relaxation of the left atrium
Question
An autorhythmic heart cell is one in which

A) action potentials fire spontaneously.
B) action potentials are stimulated by internal stores of acetylcholine.
C) action potentials always occur at exactly the same frequency.
D) all filaments contract and relax with a high degree of synchrony.
E) action potentials are initiated by the autonomic nervous system.
Question
For the repolarization phase of an SA nodal cell action potential,

A) sodium and potassium channels open.
B) calcium channels open and sodium channels close.
C) calcium and potassium channels close.
D) calcium channels close and potassium channels open.
E) sodium and chloride channels open.
Question
Someone with a heart block would have

A) a long P-R interval.
B) a long T-P interval.
C) a short P-R interval.
D) a short T-P interval.
Question
Like skeletal muscle cells, cardiac muscle cells have an absolute refractory period prior to repolarization.
Question
The plateau phase of an action potential

A) occurs only in skeletal muscle and makes those fibers' contractions most forceful.
B) leads to tetanic contractions in smooth and skeletal muscle.
C) allows cardiac muscle cells to contract and then relax without locking up.
D) allows cardiac muscle cells to exhibit synchronous fibrillation.
Question
Most of the calcium that triggers contraction of cardiac muscle comes

A) into the cell through leakage channels in the sarcolemma.
B) into the cell through voltage-gated channels in the sarcolemma.
C) from the sarcoplasmic reticulum of the cell.
D) from the Golgi apparatus of the cell.
Question
During a cardiac cycle, how many of the four chambers contract at any one time?

A) 1
B) 2
C) 4
D) Highly variable, depending on the heart beat rate
E) None of the choices is correct.
Question
In an ECG, what does the T wave represent?

A) Depolarization of the atria
B) Depolarization of the right ventricle
C) Repolarization of the ventricles
D) Closure of the AV valves
E) Depolarization of the left ventricle
Question
During the S-T segment, what is occurring within cardiac muscle cells?

A) Sodium is rapidly diffusing out of atrial muscle cells.
B) Sodium channels are beginning to open in ventricular cells and calcium is entering through slow channels in atrial cells.
C) Calcium is entering and potassium is leaving ventricular cells.
D) Potassium is entering atrial cells and sodium is leaving ventricular cells.
Question
What part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava?

A) AV bundle
B) Bundle branches
C) Purkinje fibers
D) AV node
E) SA node
Question
Which type of muscle cell exhibits a longer refractory period?

A) Cardiac muscle cell
B) Skeletal muscle cell
Question
The opening and closing of the heart valves is caused by

A) contraction and relaxation of papillary muscles that pull on heart strings.
B) pressure changes of alternating contraction and relaxation during the cardiac cycle.
C) contraction of the smooth muscle in the walls of the great vessels leaving the heart.
D) action potentials within the cusps of the valves.
Question
The atrioventricular (AV) node is located in the

A) floor of the left atrium.
B) floor of the right atrium.
C) roof of the left ventricle.
D) back wall of the right ventricle.
E) back wall of the left ventricle.
Question
Blood moves into and then out of a heart chamber because

A) it moves along its pressure gradient, and that gradient depends on contraction and relaxation during the cardiac cycle.
B) it is under constant pressure, but its movement is dictated by the control of valve openings and closures.
C) the veins and arteries constrict and dilate to propel and attract blood.
D) All of the choices are correct.
Question
In an EKG, the P wave is generated when the

A) ventricles depolarize.
B) atria depolarize.
C) atria repolarize.
D) ventricles repolarize.
E) Purkinje fibers initiate an impulse.
Question
The beginning of ventricular contraction, when all four valves are closed, is called (2 words) ________.
Question
The time that starts when a muscle cell is depolarized and ends when it is able to be restimulated is the ________ period.
Question
During ventricular contraction

A) only the AV valves open.
B) only the AV valves close.
C) only the semilunar valves close.
D) the semilunar valves close and the AV valves open.
E) the semilunar valves open and the AV valves close.
Question
Which segment of the ECG reflects the plateau phase of ventricular muscle cells' action potentials?

A) P-T segment
B) S-T segment
C) Q-R segment
D) P-R interval
E) T-P interval
Question
Someone with tachyarrhythmia would be expected to show an abnormally

A) small Q-T interval.
B) large P-R interval.
C) large R-R interval.
D) high amplitude P wave.
Question
Atrial contraction occurs just before

A) isovolumetric relaxation.
B) atrial relaxation and ventricular filling.
C) ventricular ejection.
D) isovolumetric contraction.
Question
To initiate a cardiac muscle cell contraction, calcium

A) binds to calmodulin.
B) binds to troponin.
C) binds to actin.
D) binds to the Z-disc.
E) binds to tropomyosin.
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Deck 19: Cardiovascular System: Heart
1
Which heart chambers contain deoxygenated blood?

A) Left atrium and right atrium
B) Left ventricle and right ventricle
C) Right atrium and right ventricle
D) Left atrium and left ventricle
E) Right atrium and left ventricle
C
2
Which layer is made of dense irregular connective tissue?

A) Myocardium
B) Fibrous pericardium
C) Epicardium
D) Serous pericardium
E) Endocardium
B
3
The inferior, conical end of the heart is called the ________.
apex
4
Arteries carry blood toward the heart, while veins carry blood away from the heart.
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5
Which pair is located more anteriorly in a heart in normal position?

A) Left atrium and left ventricle
B) Left atrium and right ventricle
C) Right atrium and left atrium
D) Right atrium and right ventricle
E) Right atrium and left ventricle
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6
The units for perfusion of blood are typically

A) grams per minute.
B) milliliters per minute per gram.
C) milliliters per hour per kilogram.
D) liters per gram.
E) beats per minute per gram.
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7
The serous fluid within the pericardial cavity works to

A) lubricate membranes of the pericardium.
B) slow the heart rate.
C) equalize the pressure in the great vessels.
D) eliminate blood pressure spikes.
E) All of the choices are correct.
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k this deck
8
The term "epicardium" is another name for the

A) visceral layer of the serosal pericardium.
B) parietal layer of the serosal pericardium.
C) external layer of the fibrous pericardium.
D) myocardium.
E) mediastinum.
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9
Which circuit of the cardiovascular system includes the left ventricle and aorta?

A) Pulmonary circuit
B) Cardio circuit
C) Coronary circuit
D) Systemic circuit
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10
Occlusion of blood vessels tends to lead to

A) increases in perfusion.
B) increases in capillary exchange.
C) inadequate blood supply and damage to body tissues.
D) defibrillation of cardiac muscle cell contraction.
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k this deck
11
Which can be used to characterize blood flow in the human body?
A: There is a unidirectional blood flow.
B: Arteries always carry oxygenated blood.
C: Veins always carry deoxygenated blood.
D: Arteries carry blood away from the heart.
E: Veins carry blood toward the heart.

A) a, c, d, e
B) a, b, c, d, e
C) a, d, e
D) b, c, d, e
E) d, e
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12
The pericardial cavity is between the

A) heart muscle and serous pericardium.
B) fibrous and serous layers of the pericardium.
C) visceral and parietal layers of the serous pericardium.
D) parietal and myocardial layers of the fibrous pericardium.
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13
The main functions of the cardiovascular system include the transport and exchange of respiratory gases, nutrients, and wastes throughout the body.
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14
Which circuit of the cardiovascular system is responsible for sending blood to the kidneys, stomach, and pelvic regions?

A) Pulmonary circuit
B) Visceral circuit
C) Coronary circuit
D) Systemic circuit
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15
Which correctly describes the heart's apex?

A) Projects slightly anteroinferiorly toward the left side of the body
B) Projects slightly anteroinferiorly toward the right side of the body
C) Projects slightly posteroinferiorly toward the left side of the body
D) Projects slightly posteroinferiorly toward the right side of the body
E) Projects slightly posteroinferiorly toward the midline of the body
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16
The receiving chambers of the heart are the atria, and the forcefully pumping chambers of the heart are the ventricles.
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17
Which of the cardiovascular system's circuits has deoxygenated blood in its arteries?

A) Pulmonary circuit
B) Visceral circuit
C) Coronary circuit
D) Systemic circuit
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18
The base of the heart faces in the ________ directions.

A) anterior and inferior
B) anterior and superior
C) posterior and superior
D) posterior and inferior
E) None of these choices is correct.
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19
Which carries oxygenated blood from the lungs to the heart?

A) Pulmonary arteries
B) Pulmonary veins
C) Pulmonary trunk
D) Inferior vena cava
E) Superior vena cava
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20
The pulmonary trunk receives blood from the right ventricle and conducts it toward the lung. The pulmonary trunk is a(n)

A) artery.
B) capillary.
C) vein.
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21
The pericardium helps prevent overfilling of the heart and it lessens the friction of movements during heartbeats.
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22
Metabolically, cardiac muscle relies on

A) aerobic metabolism using glycolysis of glycogen to meet most ATP demands.
B) aerobic metabolism using many mitochondria and a rich supply of myoglobin.
C) anaerobic metabolism using glycolytic enzymes to quickly generate ATP.
D) anaerobic metabolism using myoglobin, creatin kinase, and ketone bodies.
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23
Myofibrils within cardiac muscle cells are aligned in sarcomeres.
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24
Deep to the interventricular sulci is the thick muscular wall that divides the left and right ventricles, known as the interventricular ________.
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25
Contrast the length-tension relationship for cardiac muscle to that which is found in skeletal muscle. In other words, for each type of muscle, what is the optimal length? How is such an arrangement adaptive to cardiac muscle?
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26
Which feature permits the compression necessary to pump large volumes of blood out of the ventricles?

A) Negative pressure inside the ventricles
B) Absence of oxygenated blood in the atria
C) Arrangement of cardiac muscle in the heart wall
D) Presence of skeletal muscle tissue in the heart skeleton
E) Presence of papillary muscles in the ventricles
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27
Which describes the endocardium?
A: Has single layer of epithelium
B: Has layer of areolar connective tissue
C: Epithelial cells are squamous
D: Epithelial cells are cuboidal
E: Has layer of adipose connective tissue
F: Has patches of myocardium

A) a, b, c
B) a, b, d
C) a, d, e
D) a, b, c, e
E) a, e, f
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28
The papillary muscles attach to the cusps of the atrioventricular valves by means of the

A) pectinate muscles.
B) trabeculae carneae.
C) conus arteriosus.
D) tendinous cords.
E) tricuspid valve.
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29
Each of the receiving chambers of the heart has a wrinkled flaplike extension; the one that is more visible from an anterior view is the

A) interatrial septum.
B) interventricular septum.
C) left auricle.
D) right auricle.
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30
What are the cell-to-cell contacts of the cardiac muscle fibers called?

A) Z discs
B) T-tubules
C) Intercalated discs
D) Cardiac discs
E) Sarcoplasmic reticulum
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31
The atria are separated from the ventricles externally by the

A) anterior interventricular sulcus.
B) posterior interventricular sulcus.
C) sinoventricular sulcus.
D) coronary sulcus.
E) None of the choices is correct.
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32
Which are functions performed by the fibrous skeleton of the heart?
A: Separates the atria and ventricles
B: Anchors the heart valves
C: Provides electrical insulation between the atria and ventricles
D: Provides the framework for the attachment of the myocardium
E: None of these are true functions of the fibrous skeleton of the heart

A) a, d
B) b, d
C) a, c, d
D) a, b, c, d
E) e
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33
Which are differences between cardiac muscle tissue and skeletal muscle tissue?
A: The sarcoplasmic reticulum in cardiac muscle is less extensive.
B: The sarcoplasmic reticulum in cardiac muscle is more organized.
C: Cardiac muscle has intercalated discs; skeletal muscle does not.
D: Cardiac muscle has 1 or 2 nuclei per cell; skeletal muscle has multiple nuclei per cell.
E: Cardiac muscle has more well-defined terminal cisternae.

A) a, c, d
B) a, c, e
C) b, c, e
D) a, b, e
E) b, d, e
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34
The metabolic pathways of cardiac muscle make it

A) somewhat susceptible to heart attack, because it relies so exclusively on aerobic metabolism.
B) extremely susceptible to heart attack, because it uses such a variety of fuel sources.
C) somewhat susceptible to heart attack, because it has so few mitochondria.
D) relatively resistant to heart attack, because it uses exclusively anaerobic metabolism.
E) relatively resistant to heart attack, because it has a great capacity to accrue oxygen debt.
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35
The layer of the heart wall composed of cardiac muscle tissue is the

A) pericardium.
B) myocardium.
C) endocardium.
D) pericardial cavity.
E) pectinate muscle.
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36
Pectinate muscles are found on the

A) posterior wall of the right ventricle.
B) anterior wall of the right ventricle.
C) internal walls of the right and left atria.
D) posterior walls of the right and left ventricles.
E) external wall of the right atrium.
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37
The posterior interventricular sulcus

A) is another name for the coronary sulcus.
B) contains the great cardiac vein and coronary sinus.
C) is a groove between the ventricles on the back of the heart.
D) is a valve in the interventricular septum that closes at birth.
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38
The fossa ovalis appears just above the opening of the coronary sinus within the

A) left atrium.
B) left ventricle.
C) right atrium.
D) right ventricle.
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39
From which view is the connection between the pulmonary veins and the heart most visible?

A) Anterior view
B) Posterior view
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40
The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges called

A) conus arteriosus.
B) atrioventricular opening.
C) trabeculae carneae.
D) tendinous cords.
E) pectinate muscles.
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41
The heart valves

A) stabilize and hold the arteries leaving the heart.
B) permit the passage of blood in one direction.
C) separate the right and left sides of the heart.
D) are only used in the fetal heart.
E) direct the conduction impulse through the heart muscle.
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42
SA nodal cells are autorhythmic.
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43
Once an SA nodal cell reaches threshold, the depolarization phase occurs during which

A) potassium comes in through fast voltage-gated channels.
B) calcium comes in through fast voltage-gated channels.
C) potassium moves out through fast voltage-gated channels.
D) sodium moves out through slow voltage-gated channels.
E) calcium moves out through slow voltage-gated channels.
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44
Cardiac muscle is able to use a variety of fuel types for cellular respiration.
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45
Which valve prevents the backflow of blood into the left ventricle when the ventricles relax?

A) Left atrioventricular valve
B) Aortic semilunar valve
C) Right atrioventricular valve
D) Pulmonary semilunar valve
E) None of the choices is correct.
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46
During the plateau phase of a cardiac muscle cell's action potential, the membrane stays

A) depolarized as potassium exits and calcium enters.
B) depolarized as potassium enters and calcium exits.
C) repolarized as sodium enters and calcium exits.
D) hyperpolarized as sodium and calcium exit.
E) hyperpolarized as potassium enters and calcium exits.
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47
Typically, there are ________ papillary muscles that project from the wall of the left ventricle and attach to the tendinous cords that support the left AV valve.

A) three
B) two
C) a highly variable number of
D) six
E) no
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48
As with action potentials in other types of cells, the repolarization of cardiac muscle cells involves the

A) entrance of calcium through voltage-gated channels.
B) exit of potassium through voltage-gated channels.
C) entrance of sodium through voltage-gated channels.
D) binding of ACh to ACh receptor.
E) simultaneous closure of sodium channels and opening of calcium channels.
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49
At the AV node of the conduction system, the action potential is

A) rapidly advanced due to the cells being large and well connected by gap junctions.
B) rapidly advanced due to the cells being small and well insulated by myelin.
C) delayed due to the cells being small and having few gap junctions.
D) delayed due to the cells being large and having many leakage channels.
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50
The hearts nodal cells have a more negative resting potential than neurons do, because nodal cells lack leak channels for sodium and potassium ions.
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51
The membrane of a contractile cardiac muscle cell contains

A) no calcium pumps.
B) calcium pumps that move calcium out of the cell.
C) calcium pumps that move calcium into the cell.
D) calcium pumps that open and allow calcium to diffuse down its concentration gradient to reach equilibrium.
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52
The membrane of a contractile cardiac muscle cell contains

A) fast voltage-gated sodium channels and fast voltage-gated calcium channels.
B) fast voltage-gated sodium channels and slow voltage-gated calcium channels.
C) slow voltage-gated sodium channels and slow voltage-gated calcium channels.
D) slow voltage-gated sodium channels and fast voltage-gated calcium channels.
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53
Vagal tone refers to the

A) decreasing of the heart rate below its inherent rhythm by parasympathetic stimulation.
B) decreasing of the heart rate below its inherent rhythm by sympathetic stimulation.
C) increasing of the heart rate above its inherent rhythm by sympathetic stimulation.
D) increasing of the heart rate above its inherent rhythm by parasympathetic stimulation.
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54
As blood is pumped out of the heart and into the major arteries leaving the heart, it

A) pushes against the semilunar valves and opens them.
B) pushes against the semilunar valves and closes them.
C) fills the cusps of the semilunar valves, causing them to expand and block the backflow of blood
D) pushes against the atrioventricular valves and opens them.
E) fills the cusps of the atrioventricular valve causing opening of the bicuspid and closure of the tricuspid.
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55
How many half-moon shaped, pocketlike cusps are found in each semilunar valve?

A) 1
B) 2
C) 3
D) 4
E) 6
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56
Nodal cells contain fast voltage-gated calcium channels.
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57
What is the sequence of events in the transmission of an impulse through the heart muscle?
A: AV node
B: AV bundle
C: SA node
D: Through the atria
E: Through the ventricles
F: Bundle branches
G: Purkinje fibers

A) c, d, a, b, f, g, e
B) d, b, a, c, f, g, e
C) b, a, d, c, f, g, e
D) f, g, d, c, b, a, e
E) c, d, a, f, b, g, e
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58
Which action leads to the closure of the right atrioventricular valve?

A) Contraction of the right atrium
B) Contraction of the left atrium
C) Contraction of the right ventricle
D) Relaxation of the right ventricle
E) Relaxation of the left atrium
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59
An autorhythmic heart cell is one in which

A) action potentials fire spontaneously.
B) action potentials are stimulated by internal stores of acetylcholine.
C) action potentials always occur at exactly the same frequency.
D) all filaments contract and relax with a high degree of synchrony.
E) action potentials are initiated by the autonomic nervous system.
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60
For the repolarization phase of an SA nodal cell action potential,

A) sodium and potassium channels open.
B) calcium channels open and sodium channels close.
C) calcium and potassium channels close.
D) calcium channels close and potassium channels open.
E) sodium and chloride channels open.
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61
Someone with a heart block would have

A) a long P-R interval.
B) a long T-P interval.
C) a short P-R interval.
D) a short T-P interval.
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62
Like skeletal muscle cells, cardiac muscle cells have an absolute refractory period prior to repolarization.
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63
The plateau phase of an action potential

A) occurs only in skeletal muscle and makes those fibers' contractions most forceful.
B) leads to tetanic contractions in smooth and skeletal muscle.
C) allows cardiac muscle cells to contract and then relax without locking up.
D) allows cardiac muscle cells to exhibit synchronous fibrillation.
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64
Most of the calcium that triggers contraction of cardiac muscle comes

A) into the cell through leakage channels in the sarcolemma.
B) into the cell through voltage-gated channels in the sarcolemma.
C) from the sarcoplasmic reticulum of the cell.
D) from the Golgi apparatus of the cell.
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65
During a cardiac cycle, how many of the four chambers contract at any one time?

A) 1
B) 2
C) 4
D) Highly variable, depending on the heart beat rate
E) None of the choices is correct.
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66
In an ECG, what does the T wave represent?

A) Depolarization of the atria
B) Depolarization of the right ventricle
C) Repolarization of the ventricles
D) Closure of the AV valves
E) Depolarization of the left ventricle
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67
During the S-T segment, what is occurring within cardiac muscle cells?

A) Sodium is rapidly diffusing out of atrial muscle cells.
B) Sodium channels are beginning to open in ventricular cells and calcium is entering through slow channels in atrial cells.
C) Calcium is entering and potassium is leaving ventricular cells.
D) Potassium is entering atrial cells and sodium is leaving ventricular cells.
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68
What part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava?

A) AV bundle
B) Bundle branches
C) Purkinje fibers
D) AV node
E) SA node
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69
Which type of muscle cell exhibits a longer refractory period?

A) Cardiac muscle cell
B) Skeletal muscle cell
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70
The opening and closing of the heart valves is caused by

A) contraction and relaxation of papillary muscles that pull on heart strings.
B) pressure changes of alternating contraction and relaxation during the cardiac cycle.
C) contraction of the smooth muscle in the walls of the great vessels leaving the heart.
D) action potentials within the cusps of the valves.
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71
The atrioventricular (AV) node is located in the

A) floor of the left atrium.
B) floor of the right atrium.
C) roof of the left ventricle.
D) back wall of the right ventricle.
E) back wall of the left ventricle.
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72
Blood moves into and then out of a heart chamber because

A) it moves along its pressure gradient, and that gradient depends on contraction and relaxation during the cardiac cycle.
B) it is under constant pressure, but its movement is dictated by the control of valve openings and closures.
C) the veins and arteries constrict and dilate to propel and attract blood.
D) All of the choices are correct.
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73
In an EKG, the P wave is generated when the

A) ventricles depolarize.
B) atria depolarize.
C) atria repolarize.
D) ventricles repolarize.
E) Purkinje fibers initiate an impulse.
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74
The beginning of ventricular contraction, when all four valves are closed, is called (2 words) ________.
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75
The time that starts when a muscle cell is depolarized and ends when it is able to be restimulated is the ________ period.
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76
During ventricular contraction

A) only the AV valves open.
B) only the AV valves close.
C) only the semilunar valves close.
D) the semilunar valves close and the AV valves open.
E) the semilunar valves open and the AV valves close.
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77
Which segment of the ECG reflects the plateau phase of ventricular muscle cells' action potentials?

A) P-T segment
B) S-T segment
C) Q-R segment
D) P-R interval
E) T-P interval
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78
Someone with tachyarrhythmia would be expected to show an abnormally

A) small Q-T interval.
B) large P-R interval.
C) large R-R interval.
D) high amplitude P wave.
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79
Atrial contraction occurs just before

A) isovolumetric relaxation.
B) atrial relaxation and ventricular filling.
C) ventricular ejection.
D) isovolumetric contraction.
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80
To initiate a cardiac muscle cell contraction, calcium

A) binds to calmodulin.
B) binds to troponin.
C) binds to actin.
D) binds to the Z-disc.
E) binds to tropomyosin.
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