CHAPTER 8 QUIZ

Which chamber of the heart has the thickest wall?

• Left atrium
• Right atrium
• Left ventricle
• Right ventricle

Which valve prevents the backflow of blood from the left ventricle to the left atrium?

• Tricuspid valve

• Pulmonary valve

• Aortic valve

• Bicuspid (mitral) valve

What is the function of the sinoatrial (SA) node in the heart?

• To pump oxygenated blood to the lungs

• To act as the heart’s pacemaker, generating electrical impulses

• To prevent blood backflow into the ventricles

• To pump deoxygenated blood to the left atrium

Which of the following statements about the cardiac cycle is correct?

• The ventricles contract before the atria

• The atrioventricular (AV) node directly initiates the heartbeat

• The “lub” sound is produced by the closing of the AV valves

• The T wave in an ECG represents ventricular depolarization

Which vessel carries oxygenated blood from the lungs to the heart?

• Aorta

• Pulmonary vein

• Pulmonary artery

•  Vena cava

Which statement about the regulation of heart rate is correct?

• An increase in blood pH will cause the heart rate to increase

•  The cardioacceleratory center in the medulla oblongata reduces heart rate

• The vagus nerve releases acetylcholine to decrease heart rate

• The sympathetic nervous system decreases the heart rate

During which phase of the cardiac cycle are the semilunar valves open?

• Atrial systole and ventricular systole

• Ventricular systole and ventricular diastole

• Atrial and ventricular diastole

The (a)   node is known as the pacemaker of the heart.

The right atrium receives (a)   blood from the body via the vena cava.

The left ventricle pumps blood into the (a)   , which distributes oxygenated blood to the body.