______ is to slow heart rate as _____ is to fast heart rate.

______ is to slow heart rate as _____ is to fast heart rate.

a. Tachycardia; bradycardia
b. Bradycardia; tachycardia

Answer: B

During the T wave of the electrocardiogram, the ventricles are

During the T wave of the electrocardiogram, the ventricles are

a. depolarizing
b. repolarizing
c. contracting
d. relaxing
e. both B and D

Answer: E

Intercalated discs serve to transfer _____ from cell to cell.

Intercalated discs serve to transfer _____ from cell to cell.

a. ionic currents
b. action potentials
c. the force of contraction
d. all of the above
e. A and B only

Answer: D

The wall of the left ventricle is thicker than the right because

The wall of the left ventricle is thicker than the right because 

a. the left ventricle does more work than the right ventricle
b. the left ventricle pumps a greater volume of blood than the right ventricle
c. the left ventricle produces a higher pressure than the right
d. both A and B
e. both A and C

Answer: E

The first heart sound is heard when the

The first heart sound is heard when the 

a. AV valves open
b. AV valves close
c. semilunar valves close
d. atria contract
e. blood enters the aorta

Answer: B

The normal pacemaker of the heart is located in the

The normal pacemaker of the heart is located in the 

a. Purkinje fibers
b. SA node
c. AV node
d. wall of left ventricle
e. both left and right ventricles

Answer: B

In cardiac muscle, the fast depolarization phase of the action potential is the result of

In cardiac muscle, the fast depolarization phase of the action potential is the result of 

a. increased membrane permeability to Na ions
b. increased membrane permeability to K ions
c. decreased membrane permeability to Ca ions
d. decreased membrane permeability to Na ions
e. increased membrane permeability to Cl ions

Answer: A

The heart is innervated by ____ nerves.

The heart is innervated by ____ nerves.

a. parasympathetic
b. sympathetic
c. both parasympathetic and sympathetic
d. neither parasympathetic nor sympathetic
e. somatomotor

Answer: C

Blood is supplied by to the myocardium by

Blood is supplied by to the myocardium by

a. the coronary sinus
b. contact with blood in the pumping chambers
c. the coronary arteries
d. arteries that branch from the pulmonary arteries
e. both A and C

Answer: C

The pulmonary semilunar valve prevents backward flow into the

The pulmonary semilunar valve prevents backward flow into the 

a. aorta
b. pulmonary trunk
c. pulmonary veins
d. right ventricle
e. left atrium

Answer: D

As blood leaves the right ventricle it passes through the _____ and then into the pulmonary trunk.

As blood leaves the right ventricle it passes through the _____ and then into the pulmonary trunk.

a. pulmonary veins
b. conus arteriosus
c. aorta
d. inferior vena cava
e. superior vena cava

Answer: B