Worksheet Questions

An autorhythmic heart cell is one in which

• action potentials fire spontaneously.

• action potentials are stimulated by internal stores of acetylcholine.

• action potentials always occur at exactly the same frequency.

• all filaments contract and relax with a high degree of synchrony.

• action potentials are initiated by the autonomic nervous system.

What would cause a decrease in cardiac output?

• An increase in venous return

• An increase in afterload

• Addition of positive inotropic agents

• A rise in heart rate

The function of the coronary sinus is to

• connect the top and bottom halves of the heart.

• guide the aorta out of the heart.

• collect blood from the myocardium and return it to the right atrium.

The great cardiac vein runs alongside the

• anterior interventricular artery.

• posterior interventricular artery.

• right marginal artery.

• coronary sinus.

Sympathetic innervation of the heart Which of the above are correct?

• increases the heart rate

• decreases the heart rate

• increases the force of contractions

• decreases the force of contractions

• has no effect on contraction force

Tags

NGSS.HS-LS1-3

The pulmonary trunk receives blood from the right ventricle and conducts it toward the lung. The pulmonary trunk is a(n)

• artery.

• capillary.

• vein.

Which type of muscle cell exhibits a longer refractory period?

• Cardiac muscle cell

• Skeletal muscle cell

It is the contraction of the atria during atrial systole that completes the filling of the ventricles while the ventricles are in diastole.

• true

• false

Parasympathetic innervation influences the heart rate, but generally tends to have no direct effect on the force of contractions.

• true

• false

Cardiac reserve is greater in a nonathletic individual than in a highly trained athlete.

• true

• false