Heart MCQ

Cardiac muscle cells differ from skeletal muscle cells in that: A. skeletal muscle cells are voluntary but cardiac muscle cells are not. B. skeletal muscle cells are branched but cardiac muscle cells are not. C. cardiac muscle cells are multinucleate but skeletal muscle cells are not. D. cardiac muscle cells are a syncytium while skeletal muscle does not.

A

The heart can be made to beat faster by which of the following? A. sympathetic stimulation of the SA node B. sympathetic stimulation of the AV node C. parasympathetic stimulation of the SA node D. parasympathetic stimulation of the AV node

A

The heart receives its own oxygenated blood supply via the A. coronary arteries B. the pulmonary veins C. the coronary sinus D. the foramen ovale

A

Through which valve does blood flow when it moves from the right atrium into the right ventricle? A. the tricuspid valve B. the mitral valve C. the pulmonary valve D. the bicuspid valve

A

What is the name of the valve between the left atrium and the left ventricle? A. mitral valve B. tricuspid valve C. semi-lunar valve D. aortic valve

A

What is the outermost layer of the heart wall known as? A. epicardium B. pericardium C. parietal membrane D. endocardium

A

What is ventricular systole? It A. refers to contraction of the ventricles B. occurs at the same time as contraction of the atria C. occurs while the bicuspid valve is open D. refers to relaxation of the ventricles

A

What structure in the heart prevents backflow of blood into the right atrium? A. The tricuspid valve B. The bicuspid valve C. The mitral valve. D. The foramen ovale

A

What supplies blood to the myocardium? A. the coronary circulation. B. the vena cavae. C. the vasa recta. D. the pulmonary circulation.

A

Where is the mitral valve of the heart located? Between the A. left atrium and left ventricle B. left ventricle and the aorta C. right ventricle and the pulmonary trunk D. right atrium and right ventricle

A

Which chamber of the heart has the thickest myocardium? A. left ventricle B. right ventricle C. left atrium D. right atrium

A

Which of the following does limb lead II of a typical electrocardiogram represent? A. A graph of the variation of voltage produced by the heart against time. B. The voltage at right arm (RA) plus the voltage at left leg (LL). C. The electrical events that precede the contraction of the ventricles. D. The projection of the electric dipole vector of the heart on the line from left arm (LA) to right arm (RA).

A

Why is the myocardium of the right ventricle (RV) thinner than that of the left ventricle (LV)? A. the RV pumps into the pulmonary circuit which has less resistance than the systemic circuit. B. the RV pumps a smaller volume of blood than the LV. C. the RV pumps blood out with a slower exit speed than the RV. D. the RV chamber has a smaller volume than the LV.

A

How are cardiac cells mechanically attached to each other? By their: A. mitochondria B. intercalated discs C. gap junctions D. sarcolemma

B

Starting at the APEX of the heart and moving superiorly, what is the correct order in which you would encounter the four anatomical structures below? A. valves, chordae tendonae, papillary muscle, ventricle B. ventricle, papillary muscle, chordae tendonae, valves C. papillary muscle, chordae tendonae, ventricle, valves D. chordae tendonae, valves, ventricle, papillary muscle

B

The tricuspid valve separates which two structures? A. right ventricle and pulmonary trunk B. right ventricle and right atrium C. left ventricle and aorta D. left ventricle and left atrium

B

Through which valve does blood flow when it moves from the left atrium into the left ventricle? A. the semilunar valve B. the mitral valve C. the tricuspid valve D. the bicuspid valve

B

What is meant by a diastolic blood pressure of 100 mm Hg? A. the maximum pressure at the start of the aorta during ventricular contraction. B. the minimum pressure at the start of the aorta before the start of a ventricular contraction. C. the maximum pressure at the start of the aorta and pulmonary trunk during ventricular contraction. D. The minimum blood pressure measured when resting.

B

What will cause the sinoatrial (SA) node to depolarize more frequently? A. Acetylcholine B. Norepinephrine C. Parasympathetic stimulation D. Vagus nerve

B

What would be a possible consequence of the SA node failing to depolarise? A. the entire heart would not contract B. the heart rate will decrease C. the ventricles would not contract D. the heart rate will increase

B

Which name is NOT applied to the valve between the left ventricle and the left atrium? A. atrioventricular valve B. semilunar valve C. the bicuspid valve D. the mitral valve

B

Which of the following events occur during early ventricular systole? A. the atria are relaxed, the ventricles are filling passively, the atrioventricular valves are open B. the ventricles are starting to contract, the atrioventricular valves are closed, the semilunar valves are closed C. the atria contract, the ventricles are relaxed, the atrioventricular valves are open D. the atria are relaxed, the ventricles are starting to relax, the atrioventricular valves are opening, the semilunar valves are closing.

B

Which of the following heart structures are listed in the correct sequence of blood flow through them? A. right atrium, bicuspid valve, pulmonary valve, left ventricle. B. tricuspid valve, right ventricle, left atrium, mitral valve. C. pulmonary valve, left atrium, tricuspid valve, left ventricle. D. right ventricle, left atrium, aortic valve, left ventricle.

B

Which of the following is a difference between cardiac muscle and skeletal muscle? A. cardiac muscle is not striated (and skeletal muscle is). B. cardiac muscle fibres are branched (and skeletal muscle fibres are not). C. skeletal muscle is involuntary and is uni-nucleate (and cardiac muscle is neither). D. skeletal muscle has intercalated discs (and cardiac muscle doesn't).

B

Why is the myocardium of the left ventricle thicker than that of the right ventricle? A. The left ventricle has to pump a greater volume of blood than the right ventricle. B. The resistance of the systemic circulation is greater than that of the pulmonary circulation. C. The left ventricle has to pump blood to the brain against gravity. D. The right ventricle is assisted by the "respiratory pump".

B

In a normal ECG trace, what does a QRS wave indicate? A. depolarisation of the atria B. repolarisation of the atria C. depolarisation of the ventricles D. repolarisation of the ventricles

C

The Frank-Starling law of the heart describes the proportional relationship between which of the following pairs? A. Stroke volume and cardiac output B. Stroke volume and end-diastolic volume C. The blood volume in the ventricles and stroke volume D. Systemic vascular resistance and stroke volume

C

The valve between the atrium and the ventricle that pumps oxygenated blood is called: A. the right atrioventricular valve B. the semilunar valve C. the mitral valve D. the tricuspid valve

C

What is the main function of mitral valve? A. to increase the pressure inside the left atrium during systole B. to prevent a drop in pressure in the aorta during diastole C. to prevent backflow from left ventricle to left atrium during systole D. to add additional blood from left atrium to left ventricle during atrial systole

C

Where does the pulmonary trunk deliver its blood to? A. the left atrium B. the right ventricle C. the lungs D. the left ventricle

C

Which is correct? In its passage through the heart, blood is pumped into the pulmonary trunk: A. after leaving the left ventricle B. after leaving the left atrium C. after passing through the right AV valve D. after passing through the left AV valve

C

Which of the following events occur during late ventricular diastole? A. the atria are relaxed, the ventricles are filling passively, the atrioventricular valves are open B. the ventricles are starting to contract, the atrioventricular valves are closed, the semilunar valves are open C. the atria contract, the ventricles are relaxed, the atrioventricular valves are open D. the atria are relaxed, the ventricles are starting to relax, the atrioventricular valves are closed, the semilunar valves are closed.

C

Which one of the following descriptions or statements about an electrocardiogram (ECG) is NOT correct? A. It is a record of the voltage changes (as measured at the body surface) due to the depolarisation of the muscle cells of the heart as it beats. B. The potentials measured by the ECG electrodes are combined in various ways to give 12 different ECGs. C. The ECG consists of the electrical events that follow the depolarisation of ventricles (PQR section), the depolarisation of atria (the S section) and the repolarisation of the ventricles (the T section). D. The value of the potential difference called "limb lead II" varies with time to produce the familiar ECG trace - a graph of voltage vs time.

C

Which structure has the thickest wall? A. the aorta B. the inter-atrial septum C. the left ventricle D. the right ventricle

C

Why is the myocardium of the right ventricle thinner than that of the left ventricle? A. the left ventricle has to pump a greater volume of blood than the right ventricle. B. it results from left ventricular hypertrophy due to increased peripheral resistance. C. it pumps blood into the low resistance pulmonary circulation. D. it pumps blood into the high resistance systemic circulation.

C

Blood flow through the heart follows which of the sequences listed below? A. from left atrium, then mitral valve, right ventricle, aorta, left ventricle B. from right atrium, then mitral valve, right ventricle, pulmonary trunk, left ventricle. C. from pulmonary trunk, then tricuspid valve, left atrium, aortic valve, aorta D. from vena cava, then right ventricle, pulmonary trunk, left ventricle, aorta.

D

By what means does an electrical signal travel from the atria to the ventricles? Via: A. gap junctions B. Purkinje fibres C. intercalated discs D. atrioventricular bundle

D

Complete the sentence correctly. The left ventricle pumps: A. more blood than the right ventricle B. blood at a lower pressure than the right ventricle C. less blood than the right ventricle D. blood at a higher pressure than the right ventricle

D

If Sarah has a stroke volume of 70 ml and a cardiac output of 5950 ml/min, which of the following is her heart rate (in beats/min)? A. 70 B. 75 C. 80 D. 85

D

What is the innermost layer of the heart wall known as? A. epicardium B. pericardium C. visceral pericardium D. endocardium

D

What is the name given to the remnant of the opening in the foetal heart that allowed the foetal lungs to be bypassed? A. coronary sinus B. foramen ovale C. interatrial septum D. fossa ovalis

D

When listening to the "lub-dup" sound of the heart with a stethoscope, what is the cause of the "dup" sound? A. The blood flowing through the open semilunar valves B. The blood flowing through the open atrioventricular valves C. The turbulent blood flow through closing atrioventricular valves D. The turbulent blood flow through closing semilunar valves

D

Which period of the heart cycle is completely occupied by the ventricles relaxing? A. atrial systole B. atrial diastole C. ventricular systole D. ventricular diastole

D

Which statement below describes blood flow through the mitral valve? A. blood flows from the right atrium into the right ventricle B. blood flows from the right ventricle into the pulmonary artery C. blood flows from the left ventricle into the aorta D. blood flows from the left atrium into the left ventricle

D

How is the fibrous pericardium attached to the surrounding structures? A. laterally to the pleural surfaces of the lungs. B. posteriorly to the sternum. C. anteriorly to trachea, main-stem bronchi and oesophagus. D. inferiorly to the clavicles.

A

A drug, such as cocaine, which stimulates the heart but does directly inhibit the heart's ability to relax, would be considered a: A. Sympatholytic B. Sympathomimetic C. Parasympatholytic D. Parasympathomimetic

B

By what name is the heart muscle known? A. epicardium B. myocardium C. pericardium D. endocardium

B

Choose the structure known as the pacemaker of the heart from the following. A. atrio-ventricular node B. sino-atrial node C. atrio-ventricular bundle D. the bundle of His

B

Which tissue is supplied with blood via the coronary arteries? A. the lungs B. the myocardium C. the corona D. the aorta

B

Where is the aortic valve located? A. between the right atrium and right ventricle B. between the right ventricle and the pulmonary trunk C. between the left ventricle and the aorta D. between the left atrium and left ventricle

C

Which period of the heart cycle is completely occupied by the ventricles contracting? A. atrial systole B. atrial diastole C. ventricular systole D. ventricular diastole

C

The mitral valve of the heart is located between the A. right atrium and right ventricle B. left ventricle and the aorta C. right ventricle and the pulmonary trunk D. left atrium and left ventricle

D

What feature distinguishes pacemaker cardiac cells from other cardiac cells? Pacemaker cardiac cells: A. require a stimulus from the vagus nerve in order to reach threshold; other cardiac cells do not. B. reach threshold with much weaker stimuli than other cardiac cells C. have gap junctions, while other cardiac cells do not D. do not require an external stimulus to reach threshold, while other cardiac cells do.

D

What feature distinguishes pacemaker cardiac cells from other myocardial cells? Pacemaker cells: A. require a stimulus from the vagus nerve in order to reach threshold, myocardial cells do not. B. reach threshold with much weaker stimuli than myocardial cells. C. have gap junctions, while myocardial cells do not. D. spontaneously generate action potentials, while myocardial cells do not.

D

What feature does cardiac muscle possess that is missing in skeletal muscle? A. striations B. multiple nuclei C. voluntary control D. intercalated discs

D