MCQs on the Circulatory System

The heart pumps oxygenated blood to the body through which structure?

• Pulmonary artery

• Aorta

• Vena cava

• Pulmonary veins

Which chamber of the heart receives deoxygenated blood from the body?

• Left atrium

• Right atrium

• Left ventricle

• Right ventricle

Which of the following heart valves is located between the left atrium and left ventricle?

• Tricuspid valve

• Pulmonary valve

• Mitral valve

• Aortic valve

Which type of blood vessel carries oxygen-rich blood from the heart to the body?

• Veins

• Arteries

• Capillaries

• Venules

The largest artery in the body is the:

• Carotid artery

• Pulmonary artery

• Aorta

• Femoral artery

Which type of blood vessel has the thinnest walls and is involved in nutrient and gas exchange?

• Veins

• Capillaries

• Arteries

• Venules

Which of the following veins returns deoxygenated blood from the upper body to the heart?

• Inferior vena cava

• Superior vena cava

• Jugular vein

• Femoral vein

What is the primary function of red blood cells (RBCs)?

• Immune response

• Oxygen transport

• Blood clotting

• Plasma protein synthesis

Which component of blood is responsible for blood clotting?

• Red blood cells

• White blood cells

• Platelets

• Plasma

Plasma makes up about what percentage of total blood volume?

• 30%

• 45%

• 55%

• 70%