Chapter 12 Example Questions

The two heart reflexes directly respond to changes in ________. A) blood volume B) hormones released C) oxygen levels in the blood D) calcium concentrations E) the pH of blood

A) blood volume

The function of an atrium is to A) collect blood returning to the heart. B) pump blood to the lungs. C) pump blood into the systemic circuit. D) prevent the movement of blood back into the ventricles. E) stabilize the position of the heart valves.

A) collect blood returning to the heart.

Relaxation of the heart chambers is called A) diastole. B) systole. C) depolarization. D) hyperpolarization. E) repolarization.

A) diastole.

Each cardiac muscle cell is bound to its neighboring cells at sites called ________. A) intercalated discs B) myofibrils C) sarcomeres D) trabeculae E) fossa ovalis

A) intercalated discs

In ________, the cusps of the bicuspid valves do not close properly. A) mitral valve prolapse B) valvular heart disease C) ventricular stenosis D) myocardial infarctions E) aortic sinuses

A) mitral valve prolapse

The loose-fitting sac around the heart is lined by the A) parietal pericardium. B) epicardium. C) endocardium. D) parietal myocardium. E) parietal endocardium.

A) parietal pericardium.

The first blood vessels to branch from the pulmonary trunk are the A) pulmonary arteries. B) bronchial arteries. C) circumflex arteries. D) carotid arteries. E) subclavian arteries.

A) pulmonary arteries.

The primary function of the venae cavae includes which of the following? A) return blood to the right atrium B) pump oxygenated blood into circulation C) remove excess fluid from the heart chambers D) anchor the heart to surrounding structures E) prevent expansion of the heart

A) return blood to the right atrium

Blood returning directly from the systemic circulation enters the A) right atrium. B) right ventricle. C) left atrium. D) left ventricle. E) pulmonary trunk.

A) right atrium.

Which of the following is greatest during left ventricular systole? A) the pressure in the ventricle B) the pressure in the aorta C) the pressure in the left atrium D) the pressure in the arteries E) the pressure in the right atrium

A) the pressure in the ventricle

In which situation would the filling time (duration of ventricular diastole) be the longest? A) when heart rate is slow B) when heart rate is fast C) when the force of contraction is decreased D) when the difference between the end diastolic volume and the end systolic volume is small E) when calcium channel blockers are present

A) when heart rate is slow

________ is a condition in which the heart rate is slower than normal. A) Cardiac arrhythmia B) Bradycardia C) Tetanus D) Summation E) Tachycardia

B) Bradycardia

Which statement regarding autonomic innervation of the heart is accurate? A) The release of norepinephrine (NE) and epinephrine (E) by the adrenal medulla decreases the force and degree of contraction. B) Norepinephrine released by sympathetic neurons increases the heart rate. C) Acetylcholine released by parasympathetic neurons results in increased heart rate. D) Parasympathetic release of norepinephrine at synapses in the myocardium result in an increase in stroke volume. E) Acetylcholine released by sympathetic neurons result in an increase in the force of cardiac contractions.

B) Norepinephrine released by sympathetic neurons increases the heart rate.

The cardiac pacemaker cells are located in which of the following? A) Purkinje fibers B) SA node C) AV node D) bundle branches E) bundle of His

B) SA node

Atrioventricular valves prevent backflow into the A) ventricles. B) atria. C) venae cavae. D) aorta. E) pulmonary trunk.

B) atria.

Under conditions of hypocalcemia, A) cardiac muscle cells become lethargic. B) cardiac muscle contractions become very weak. C) cardiac muscles become extremely excitable. D) cardiac muscle cells remain the same. E) cardiac muscle contraction becomes prolonged.

B) cardiac muscle contractions become very weak.

When the ventricles are relaxed, the ________ are loose and there is no resistance to the flow of blood from atrium to ventricle. A) auricles B) chordae tendineae C) papillary muscles D) trabeculae carneae E) aortic sinuses

B) chordae tendineae

The first heart sound ("lubb") is produced as the atrioventricular valves ________ and the semilunar valves ________. A) open; close B) close; open C) open; open D) close; close E) The actions of the valves do not contribute to the heart sounds.

B) close; open

The average pressure in the right ventricle is ________ the pressure in the left ventricle. A) the same as B) considerably lower than C) slightly lower than D) slightly higher than E) much higher than

B) considerably lower than

Which structural feature of the heart is a deep groove usually filled with substantial amounts of fat, marking the border between the atria and the ventricles. A) posterior interventricular sulcus B) coronary sulcus C) anterior interventricular sulcus D) coronary sinus E) interventricular septum

B) coronary sulcus

In ventricular reflex, a more powerful contraction results in A) decreased stroke volume. B) increased stroke volume. C) no change in stroke volume. D) decreased cardiac output. E) a slower heart rate.

B) increased stroke volume.

Blood from the viscera and the lower limbs is conducted to the heart through which vessel? A) coronary sinus B) inferior vena cava C) pulmonary veins D) superior vena cava E) cardiac vein

B) inferior vena cava

The pulmonary arteries carry blood to the A) heart. B) lungs. C) brain. D) kidneys. E) pancreas.

B) lungs.

The muscle layer of the heart is the ________. A) epicardium B) myocardium C) endocardium D) visceral pericardium E) endothelium

B) myocardium

The cardioinhibitory center controls activities of the ________ motor neurons. A) ganglionic B) parasympathetic C) postganglionic D) preganglionic E) sympathetic

B) parasympathetic

The left atrium receives oxygenated blood from the A) pulmonary trunk. B) pulmonary veins. C) aorta. D) inferior vena cava. E) pulmonary arteries.

B) pulmonary veins.

The amount of blood ejected by a ventricle during a single beat is called the A) heart rate. B) stroke volume. C) cardiac output. D) end diastolic volume. E) end systolic volume.

B) stroke volume.

A faster-than-normal heart rate is called ________. A) bradycardia B) tachycardia C) tetanus D) myocardial infarctions E) arrhythmias

B) tachycardia

The amount of blood conveyed to the right atrium is referred to as the ________. A) cardiac output B) venous return C) stroke volume D) P-R interval E) Q-T interval

B) venous return

The maximum rate of contraction in normal cardiac muscle fibers is ________ per minute. A) 80 B) 140 C) 200 D) 250 E) 300+

C) 200

The following is a list of vessels and structures that are associated with the heart. 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. vena cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins What is the correct order for the flow of blood entering from the systemic circulation? A) 1, 2, 7, 8, 3, 4, 6, 5 B) 1, 7, 3, 8, 2, 4, 6, 5 C) 5, 1, 3, 7, 8, 2, 4, 6 D) 5, 3, 1, 7, 8, 4, 2, 6 E) 5, 1, 3, 8, 7, 2, 4, 6

C) 5, 1, 3, 7, 8, 2, 4, 6

________ release results in a decrease in the force of cardiac contractions. A) Norepinephrine B) Epinephrine C) Acetylcholine D) Digitalis E) Glucagon

C) Acetylcholine

Choose the correct statement regarding the atrial reflex. A) It involves triggering a reflexive decrease in the heart rate through increased parasympathetic activity. B) It involves stimulating pain receptors in the right atrial walls as blood enters the right atrium. C) It involves adjustments in the heart rate in response to an increase in the venous return. D) It involves sympathetic stimulation, which results in increased heart rate. E) It involves parasympathetic stimulation, which increases the heart rate.

C) It involves adjustments in the heart rate in response to an increase in the venous return.

The release of norepinephrine at synapses in the myocardium results in ________. A) a decrease in the force of cardiac contractions B) inhibition of cardiac muscle cell metabolism C) an increase in stroke volume D) a decreased heart rate E) a decrease in cardiac output

C) an increase in stroke volume

The property of heart muscle in which it contracts in the absence of neural or hormonal stimulation is called ________. A) tamponade B) thrombosis C) autorhythmicity D) arrhythmias E) tetanus

C) autorhythmicity

The great and middle cardiac veins drain blood directly into the A) superior vena cava. B) inferior vena cava. C) coronary sinus. D) coronary sulcus. E) aorta.

C) coronary sinus.

Which structural feature of cardiac muscle cells enables action potentials to travel rapidly from cell to cell? A) mitochondria B) desmosomes C) gap junctions D) myofibrils E) myoglobin

C) gap junctions

Which of the following most likely occurs in the condition called hyperkalemia? A) decreased heart rate B) increased rate of depolarization at the SA node C) irregular cardiac contractions D) fluid collection in the pericardial sac E) elevated calcium concentrations

C) irregular cardiac contractions

The right ventricle pumps blood to the A) left atrium. B) left ventricle. C) lungs. D) systemic circuit. E) right atrium.

C) lungs.

The atrioventricular valve on the left side of the heart is often called the A) tricuspid valve. B) cuspid valve. C) mitral valve. D) pulmonary valve. E) aortic valve.

C) mitral valve.

The right atrium receives blood from the systemic circuit and pumps it to the ________. A) aorta B) left atrium C) right ventricle D) pulmonary trunk E) muscle tissue of the heart wall

C) right ventricle

The ________ circuit carries blood to and from all parts of the body except the lungs. A) pulmonary B) coronary C) systemic D) systolic E) diastolic

C) systemic

The second heart sound is heard when A) the AV valves open. B) the AV valves close. C) the semilunar valves close. D) the atria contract. E) blood enters the aorta.

C) the semilunar valves close.

Blood from the systemic circulation returns to the heart by way of the A) coronary sinus. B) pulmonary veins. C) venae cavae. D) aorta. E) pulmonary arteries.

C) venae cavae.

According to the Frank-Starling principle, the cardiac output is directly related to (the) A) size of the ventricle. B) heart rate. C) venous return. D) thickness of the myocardium. E) total amount of blood in the cardiovascular system.

C) venous return.

The semilunar valves prevent backflow into the A) atria. B) aorta. C) ventricles. D) pulmonary trunk. E) venae cavae.

C) ventricles.

The QRS complex on an ECG tracing represents A) atrial depolarization. B) atrial repolarization. C) ventricular depolarization. D) ventricular repolarization. E) ventricular contraction.

C) ventricular depolarization.

Normal cardiac muscle is similar to normal skeletal muscle in terms of A) the duration of the action potentials, which last 250-300 msec. B) the duration of the resulting contractions. C) the refractory period, which continues until relaxation is under way. D) how an action potential leads to the appearance of calcium among the myofibrils. E) the appearance of summation of twitches.

D) how an action potential leads to the appearance of calcium among the myofibrils.

The heart is enclosed by the A) pleural cavity. B) peritoneal cavity. C) cardiac skeleton. D) mediastinum. E) coronary sinus.

D) mediastinum.

The cardiac skeleton of the heart functions to A) convey blood away from the heart. B) supply blood to the muscle tissue of the heart. C) reduce friction between the opposing surfaces of the pericardial sac. D) stabilize the position of the heart valves. E) provide for the movement of ions and small molecules.

D) stabilize the position of the heart valves.

Cardiac muscle cells have abundant reserves of myoglobin, which function in ________. A) removing waste products B) storing iron C) removing carbon dioxide D) storing oxygen E) the shortening of individual sarcomeres

D) storing oxygen

The muscular ridges found on the internal surfaces of the ventricles are collectively called (the) ________. A) cardiac skeleton B) chordae tendineae C) papilla D) trabeculae carneae E) auricle

D) trabeculae carneae

The T wave of an ECG corresponds to A) atrial depolarization. B) atrial diastole. C) ventricular systole. D) ventricular repolarization. E) atrial repolarization

D) ventricular repolarization.

Following are events that occur during the cardiac cycle. 1. Ventricular pressure increases and exceeds pressure in the arteries. 2. Ventricles fill passively. 3. Atrial relaxation begins. 4. Atrial contraction forces a small amount of additional blood into relaxed ventricles. 5. Pressure in ventricles drops and blood flows back against cusps of semilunar valves, forcing them closed. 6. Ventricular contraction pushes AV valves closed. Choose the correct order of events in the cardiac cycle. A) 4, 6, 3, 1, 2, 5 B) 2, 4, 3, 6, 1, 5 C) 3, 6, 1, 5, 4, 2 D) 2, 5, 1, 6, 3, 4 E) 4, 3, 6, 1, 5, 2

E) 4, 3, 6, 1, 5, 2

When the heart rate and stroke volume in a normal heart increase together, the cardiac output can increase by ________ percent. A) 50-70 B) 100-350 C) 150-250 D) 250-500 E) 500-700

E) 500-700

Regarding cardiodynamics, which of the following relationships is correct? A) HR = CO x SV B) SV = CO x HR C) CO = HR/SV D) SV = HR/CO E) CO = HR x SV

E) CO = HR x SV

Which statement is correct regarding the heart wall? A) The endothelium consists of cardiac muscle tissue, blood vessels, and nerves. B) The myocardium is comprised of a simple squamous epithelium and an underlying layer of areolar tissue. C) The endocardium is the visceral pericardium. D) The cardiac muscle tissue forms bands that wrap around the ventricles and spiral into the wall of the atria. E) The epicardium is a serous membrane that consists of an exposed epithelium and an underlying layer of areolar tissue.

E) The epicardium is a serous membrane that consists of an exposed epithelium and an underlying layer of areolar tissue.

Small tributaries from the branches of the coronary arteries form interconnections called ________. A) infarcts B) auricles C) regurgitations D) trabeculae carneae E) anastomoses

E) anastomoses

When arteries connect to one another, it is called an arterial ________. A) sinus B) sac C) mediastinum D) sulcus E) anastomosis

E) anastomosis

Deoxygenated blood is carried away from the right ventricle by A) venules. B) veins. C) arterioles. D) capillaries. E) arteries.

E) arteries.

Which event marks the beginning of the cardiac cycle? A) ventricular systole B) atrial diastole C) atrial arrhythmia D) ventricular diastole E) atrial systole

E) atrial systole

Regarding blood volume reflexes, "filling time" is defined as the A) amount of blood ejected by a ventricle during a single beat. B) flow of venous blood into the right atrium. C) amount of blood pumped by the left ventricle in one minute. D) duration of atrial systole. E) duration of ventricular diastole.

E) duration of ventricular diastole.

The innermost layer of the heart wall is the A) mediastinum. B) parietal pericardium. C) epicardium. D) myocardium. E) endocardium.

E) endocardium.

When a chamber fills with blood and is preparing to begin the next cardiac cycle, that chamber is A) in systole. B) in arrhythmia. C) contracting. D) depolarizing. E) in diastole.

E) in diastole.

If a decline in blood pressure or oxygen concentrations occurs, the cardiac centers then call for a(n) ________. A) decrease in cardiac output. B) decrease in sympathetic motor neuron activity. C) decrease in stroke volume. D) increase in parasympathetic motor neuron activity. E) increase in cardiac output.

E) increase in cardiac output.

The wall between the atria is called the A) ventricle. B) coronary sinus. C) coronary sulcus. D) auricle. E) interatrial septum.

E) interatrial septum.

If the AV node does not receive action potentials generated by the SA node, A) the ventricles will beat faster. B) the ventricular rate of contraction will not be affected. C) the stroke volume will increase. D) tachycardia will occur. E) it will establish a heart rate of 40-60 bpm.

E) it will establish a heart rate of 40-60 bpm.

The heart is surrounded by the ________ cavity. A) peritoneal B) valvular C) cardiac D) coronary E) pericardial

E) pericardial

During repolarization, ________ ions rush out of the ventricular contractile cell. A) sodium B) calcium C) magnesium D) selenium E) potassium

E) potassium

The marginal artery branches off the A) aorta. B) left coronary artery. C) interventricular artery. D) coronary sinus. E) right coronary artery.

E) right coronary artery.

During ventricular systole, A) the ventricles are relaxed. B) blood is entering the ventricle. C) the semilunar valves remain closed. D) the pressure in the ventricles decreases. E) the ventricles are contracting.

E) the ventricles are contracting.

If valve function deteriorates such that the heart cannot maintain adequate circulatory flow, symptoms of ________ appear. A) mitral valve prolapse B) carditis C) coronary artery disease D) rheumatic fever E) valvular heart disease

E) valvular heart disease

Match the structure in the first column with its description in the second column. _____ 1. systole _____ 2. diastole _____ 3. anastomoses _____ 4. SA node _____ 5. cardiac output A. relaxation of heart chambers B. contraction of heart chambers C. tissue mass embedded in the posterior wall of the right atrium D. amount of blood ejected by the left ventricle in one minute E. interconnections of small tributaries of major blood vessels

1-B, 2-A, 3-E, 4-C, 5-D

Which of the following is true regarding normal cardiac muscle? A) Neither summation nor tetany can occur. B) Both summation and tetany can occur. C) Summation, but not tetany, can occur. D) Tetany, but not summation, can occur. E) The refractory period of a normal cardiac muscle cell is relatively short.

A) Neither summation nor tetany can occur.

Depolarization of the atria is represented on an electrocardiogram by the A) P wave. B) T wave. C) S wave. D) QRS complex. E) PR complex.

A) P wave.

Specialized ________ convey the impulses to the contractile cells of the ventricular myocardium. A) Purkinje fibers B) nodal cells C) AV bundles D) bundle branches E) ectopic cells

A) Purkinje fibers

Veins that return blood to the heart are also referred to as ________ vessels. A) afferent B) mitral C) valvular D) efferent E) pulmonary

A) afferent

The semilunar valve of the left side of the heart prevents backflow from the A) aorta. B) pulmonary trunk. C) pulmonary veins. D) right ventricle. E) left ventricle.

A) aorta.

The right and left coronary arteries originate at the ________. A) aortic sinuses B) coronary sinus C) pulmonary trunk D) marginal artery E) fossa ovalis

A) aortic sinuses

During rapid depolarization of a ventricular contractile cell, the voltage-gated sodium channels close when the transmembrane potential reaches ________. A) -90 mV B) -30 mV C) 0 mV D) +30 mV E) +90 mV

D) +30 mV

The following are various components of the conducting system of the heart: 1 - Purkinje cells 2 - AV bundle 3 - AV node 4 - SA node 5 - bundle branches The sequence in which an action potential would move through this system is A) 1, 4, 3, 2, 5. B) 3, 2, 4, 5, 1. C) 3, 5, 4, 2, 1. D) 4, 3, 2, 5, 1. E) 4, 2, 3, 5, 1.

D) 4, 3, 2, 5, 1.

________ permit the exchange of nutrients, dissolved gases, and waste products between the blood and surrounding tissues. A) Veins B) Arteries C) Arterial trunks D) Capillaries E) Vena cavae

D) Capillaries

Abnormal patterns of cardiac activity are known as ________. A) automaticity B) ischemias C) defibrillations D) arrhythmias E) contractility

D) arrhythmias

Which of the following indicates the start of the systemic circuit? A) pulmonary trunk B) pulmonary arteries C) vena cavae D) ascending aorta E) cardiac veins

D) ascending aorta

The ________ involves acceleration of the heart rate when the walls of the right atrium are stretched. A) venous return B) stroke volume C) cardiac output D) atrial reflex E) cardiac cycle

D) atrial reflex

The tricuspid valve is located A) in the opening of the aorta. B) in the opening of the pulmonary trunk. C) where the vena cavae join the right atrium. D) between the right atrium and right ventricle. E) between the left atrium and left ventricle.

D) between the right atrium and right ventricle.

Blood flowing from the left atrium to the left ventricle flows through the ________ valve. A) aortic B) tricuspid C) pulmonary D) bicuspid E) papillary

D) bicuspid

The amount of blood pumped by the left ventricle in one minute is called the A) end diastolic volume. B) end systolic volume. C) stroke volume. D) cardiac output. E) cardiac reserve.

D) cardiac output.

A disorder resulting from the obstruction (buildup of fatty deposits) of coronary circulation is called ________. A) valvular heart disease B) rheumatic heart disease C) coronary thrombosis D) coronary artery disease E) heart block

D) coronary artery disease

In ECG tracings, extension of the P-R interval to more than 200 msec most likely can indicate which of the following? A) coronary ischemia B) congenital heart defect C) electrolyte disturbances D) damage to the conducting pathways E) hypercalcemia

D) damage to the conducting pathways

The skeleton of the heart consists of A) a reticular connective tissue within the myocardium. B) a bone in the interatrial septum. C) a bone in the interventricular septum. D) dense bands of tough, elastic connective tissue that encircle the heart valves and the bases of the aorta and pulmonary trunk. E) fibrous connective tissue in the auricle of the atrium.

D) dense bands of tough, elastic connective tissue that encircle the heart valves and the bases of the aorta and pulmonary trunk.

The left and right coronary arteries supply blood to the muscle tissue of the A) intestines. B) head. C) brain. D) heart. E) liver.

D) heart.