practice problems

Which layer forms the bulk of the heart and is the

layer that actually contracts?

a. endocardium

b. myocardium

c. endomysium

d. epicardium

b - myocardium

The ventricles of the heart contain __________.

a. pectinate muscles, crista terminalis, fossa

ovalis

b. chordae tendineae, papillary muscles, fossa

ovalis

c. trabeculae carneae, chordae tendineae,

papillary muscles

d. papillary muscles, pectinate muscles,

pulmonary trunk

c. trabeculae carneae, chordae tendineae,

papillary muscles

The aortic semilunar valve, when closed,

prevents blood from back-flowing into the

_______.

a. right atrium

b. left atrium

c. right ventricle

d. left ventricle

d - left ventricle

Horizontal ridges that line the anterior part of the

right atrium and the left auricle are known as

________.

a. papillary muscles

b. pectinate muscles

c. chordae tendineae

d. trabeculae carneae

b - pectinate muscles

The coronary sinus __________.

a. allows blood to move from ventricle to

ventricle

b. is where blood enters when leaving the right

ventricle

c. is a branch off the pulmonary trunk

d. returns almost all the venous blood from

the heart to the right atrium

d - returns almost all the venous blood from the heart to the right atrium

The pulmonary arteries __________.

a. carry deoxygenated blood to the left atrium

b. carry oxygenated blood to the left atrium

c. carry deoxygenated blood to the lungs

d. are branches of the right coronary artery

c - carry deoxygenated blood to the lungs

Which of the following is correct about the left

ventricle?

a. It generates the same contractile force as the

right ventricle.

b. It experiences only systole.

c. It pumps blood into the systemic circuit.

d. none of the above

c - it pumps blood into systemic circuit

When the atrioventricular (AV) valves close,

__________.

a. papillary muscles and chordae tendineae

prevent AV valve flaps from everting

b. the left and right atria are in systole

c. the left and right ventricles are in diastole

d. Both a and c are correct.

a papillary muscles and chord tendineae prevent AV valve flaps from everting

During mitral valve prolapse, failure of the

valvular cusps to properly close leads to

__________.

a. a clicking sound followed by a swish produced

by the backflow of blood

b. the backflow of blood into the left atrium

c. the production of the “dup” sound

d. both a and b

d - both a and b

The heart’s pacemaker is known as

__________.

a. the AV node

b. the subendocardial conducting network

c. the internodal fibers

d. the SA node

d- the SA node

Which of the following is correct about the

heart’s blood supply?

a. Coronary arteries supply the myocardium.

b. Its blood supply comes from branches of the

pulmonary veins and the aorta.

c. The one and only major coronary artery is the

coronary sinus.

d. all of the above

a - coronary arteries supply the myocardium

Until birth, the two atria are connected by a hole in

the interatrial septum called the _________.

Upon closing, it becomes the __________.

a. fossa ovalis; foramen ovale

b. foramen ovalis; fossa ovale

c. foramen ovale; fossa ovalis

d. foramen rotundum; fossa rotundis

c - foramen ovale, fossa ovalis

The defects associated with the tetralogy of

Fallot, one of a number of congenital heart

defects, include which of the following?

a. Pulmonary trunk is too narrow.

b. Wall of right ventricle is thickened.

c. Aorta opens from both ventricles.

d. all of the above

d - all of above

A patient has damage that prevents blood from flowing

through the pulmonary semilunar valve. Which chamber

would experience the most immediate increase in

pressure during ventricular systole?

A. Left atrium

B. Right atrium

C. Right ventricle

D. Left ventricle

c - right ventricle

A researcher selectively blocks gap junctions within the

intercalated discs of cardiac muscle. Which effect would

most likely occur?

A. Increased coronary blood flow

B. Failure of electrical impulses to spread efficiently between cells

C. Increased valve closure force

D. Thickening of the myocardium

b - failure of electrical impulses to spread efficiently between cells

Which structure is most directly responsible for

preventing AV valve cusps from prolapsing into the

atria during ventricular contraction?

A. Trabeculae carneae

B. Pectinate muscles

C. Chordae tendineae and papillary muscles

D. Fossa ovalis

c - chordae tendineae

A clot completely blocks the coronary sinus. Which

process would be most directly impaired?

A. Delivery of oxygen-rich blood to the myocardium

B. Drainage of venous blood from the heart muscle

C. Blood flow from the pulmonary trunk to the lungs

D. Blood return from the pulmonary veins

b - drainage of venous blood from the heart muscle

A patient’s SA node is destroyed but the AV node remains

functional. Which statement is most accurate?

A. The heart will immediately stop permanently.

B. The AV node can still generate impulses, but at a slower

intrinsic rate.

C. The ventricles will contract faster than normal.

D. The pulmonary valve will remain closed.

b - the AV node can still generate impulses, but a slower intrinsic rate

During auscultation, a clinician hears an abnormal click

at the apex of the heart. Which valve is most likely

affected?

A. Pulmonary semilunar valve

B. Aortic semilunar valve

C. Tricuspid valve

D. Mitral valve

d - mitral valve

A 17-year-old patient has congenital narrowing of the

pulmonary semilunar valve. During exercise, the right

ventricle must generate unusually high pressures to

maintain blood flow to the lungs. If the condition persists

for years, which structural change is most likely to occur

first?

A. Left atrial enlargement

B. Right ventricular hypertrophy

C. Left ventricular hypertrophy

D. Enlargement of the coronary sinus

b - right ventricular hypertrophy

A patient suffers a myocardial infarction that damages

papillary muscles attached to the mitral valve. Shortly

afterward, blood moves backward during ventricular

contraction.

Into which chamber is blood most likely regurgitating?

A. Right atrium

B. Right ventricle

C. Left atrium

D. Pulmonary trunk

c - left atrium

A physician hears a turbulent clicking sound at the

superior right point during cardiac examination. The

patient reports dizziness during exercise.

Which valve is most likely stenotic?

A. Tricuspid valve

B. Pulmonary valve

C. Mitral valve

D. Aortic valve

d - aortic valve

A blood clot becomes lodged immediately after leaving

the right ventricle.

Which vessel would contain the clot first?

A. Aorta

B. Pulmonary trunk

C. Superior vena cava

D. Pulmonary vein

b - pulmonary trunk