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 ________________ node is known as the pacemaker of the heart.

The right atrium receives ________________ blood from the body via the vena cava.

The left ventricle pumps blood into the ________________, which distributes oxygenated blood to the body.