chapter 20

Which of the following chambers receives deoxygenated blood?

• Left atrium

• Right atrium

• Left ventricle

• Aorta

What is the primary function of the pericardium?

• To generate electrical impulses

• To protect and reduce friction around the heart

• To pump oxygenated blood

• To regulate blood pressure

Which layer of the pericardium is directly attached to the heart?

• Fibrous pericardium

• Parietal layer

• Visceral layer

• Endocardium

What structure prevents backflow of blood into the left ventricle?

• Pulmonary semilunar valve

• Tricuspid valve

• Aortic semilunar valve

• Mitral valve

The left ventricle has the thickest myocardium because:

• It pumps blood into the lungs

• It has to generate high pressure to pump blood into the systemic circulation

• It stores oxygen for emergency use

• It requires more energy than the right ventricle

Which structure is known as the heart’s natural pacemaker?

• AV node

• SA node

• Purkinje fibers

• Bundle of His

What does the AV node do?

What do Purkinje fibers do?

• Carry blood to the heart

• Distribute electrical impulses through the ventricles

• Pump blood to the lungs

• Control heart rate

What is the function of the vagus nerve in heart regulation?

• Increases heart rate

• Decreases heart rate

• Regulates contraction strength

• Prevents blood clotting

What is cardiac output?

• The amount of blood pumped per minute

• The electrical impulse of the atria

• The volume of blood in the atria

• The pressure in the aorta