Cardiovascular System Quiz

Through which structure does all of the deoxygenated blood from the body come back to the heart?

• Pulmonary Artery

• Aorta

• Vena Cava

• Coronary Artery

Answer explanation

All deoxygenated blood from the body returns to the heart through the superior and inferior vena cavae, which are collectively referred to as the vena cavae. Therefore, the correct answer is 2.

What happens to the semilunar valves when intraventricular pressure falls?

• The semilunar valves open.

• The semilunar valves close.

• The semilunar valves remain unchanged.

• The semilunar valves become rigid.

Answer explanation

When intraventricular pressure falls, the pressure in the ventricles decreases, causing the semilunar valves to close to prevent backflow of blood from the arteries into the ventricles.

What is the ECG showing?

• Atrial Fibrillation

• Ventricular Fibrillation

• Heart Block

• Premature Ventricular Contraction

Answer explanation

The ECG shows irregularities in the heart's electrical conduction, indicating a delay or blockage in the signals. This is characteristic of Heart Block, distinguishing it from other arrhythmias like Atrial Fibrillation or Ventricular Fibrillation.

The T wave on an ECG printout represents

• contraction of the atria

• relaxation of the ventricles

• depolarization of the ventricles

• repolarization of the atria

Answer explanation

The T wave on an ECG represents the relaxation of the ventricles after contraction. This phase is crucial for the heart's electrical cycle, indicating that the ventricles are preparing for the next heartbeat.

What is the name of the chamber of the heart that pumps oxygenated blood to the body?

• right atrium

• left ventricle

• right ventricle

• pulmonary artery

Answer explanation

The left ventricle is the chamber of the heart responsible for pumping oxygenated blood to the body. It receives blood from the left atrium and contracts to send it through the aorta, supplying the entire body.

What is the name of the valve that controls blood flow from the right ventricle to the pulmonary artery?

• aortic valve

• mitral valve

• pulmonary valve

• tricuspid valve

Answer explanation

The pulmonary valve controls blood flow from the right ventricle to the pulmonary artery, allowing deoxygenated blood to enter the lungs for oxygenation. The aortic valve, mitral valve, and tricuspid valve serve different functions.

What is the visceral layer of the serous pericardium also called?

• Pericardial sac

• Epicardium

• Myocardium

• Endocardium

Answer explanation

The visceral layer of the serous pericardium is also known as the epicardium. It directly covers the heart, while the myocardium refers to the heart muscle and the endocardium lines the heart chambers.

What is the name of the structure labeled 8 in the diagram?

• pulmonary artery

• aorta

• vena cava

• pulmonary vein

Answer explanation

The structure labeled 8 is the pulmonary artery, which carries deoxygenated blood from the heart to the lungs for oxygenation. The aorta, pulmonary vein, and superior vena cava serve different functions in the circulatory system.

What is the role of the atrioventricular node in the cardiac cycle?

• To initiate the electrical impulse for heart contraction

• To delay the electrical impulse before it passes to the ventricles

• To regulate blood flow between the atria and ventricles

• To coordinate the contraction of the heart muscle

Answer explanation

The atrioventricular node delays the electrical impulse from the atria before it passes to the ventricles, allowing time for the ventricles to fill with blood. This is crucial for effective heart function.

What is the name of the large vein that carries deoxygenated blood from the upper body to the heart?

• inferior vena cava

• pulmonary vein

• superior vena cava

• jugular vein

Answer explanation

The superior vena cava is the large vein that carries deoxygenated blood from the upper body to the heart, while the inferior vena cava serves the lower body. The pulmonary vein carries oxygenated blood, and the aorta distributes oxygenated blood.