BIO124 Chapter 19

The heart beats approximately ________ times each day.

• 1,000,000

• 100,000

• 1,000

• 10,000

The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the

• foramen ovale.

• coronary sinus.

• ligamentum arteriosus.

• ductus arteriosis.

The atrioventricular valves permit blood flow

• in one direction.

• from a ventricle to an atrium.

• in many directions.

• in both directions.

In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the

• cardiac notch.

• ventral cavity.

• mediastinum.

• pleural space.

Contractions of the papillary muscles

• close the semilunar valves.

• prevent the atrioventricular valves from reversing into the atria.

• eject blood from the ventricles.

• eject blood from the atria into the ventricles.

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

• conus arteriosus

• pulmonary veins

• aorta

• papillary muscles

Which of the following are involved in the pulmonary circuit?

• right ventricle, pulmonary trunk, left atrium

• right ventricle, pulmonary veins, aorta

• superior vena cava, right atrium, left ventricle

• left ventricle, pulmonary veins, right atrium

The great and middle cardiac veins drain blood into the

• aorta.

• coronary sinus.

• inferior vena cava.

• superior vena cava.

The ________ covers the outer surface of the heart.

• parietal pericardium

• endocardium

• myocardium

• epicardium

The normal pacemaker of the heart is located in

• the sinoatrial node.

• the atrioventricular node.

• the Purkinje fibers.

• the wall of the left ventricle.