Y10 Circulatory System

What type of blood is carried by the pulmonary artery?

• Oxygenated

• Deoxygenated

• Mixed blood

• Plasma

Answer explanation

The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. This is the only artery in the body that transports deoxygenated blood, making 'Deoxygenated' the correct answer.

Which chamber of the heart pumps blood to the lungs?

• Left atrium

• Left ventricle

• Right atrium

• Right ventricle

Answer explanation

The right ventricle is responsible for pumping deoxygenated blood to the lungs for oxygenation. The left atrium and left ventricle handle oxygenated blood, while the right atrium receives blood from the body.

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

• Aorta

• Vena cava

• Pulmonary vein

• Pulmonary artery

Answer explanation

The pulmonary vein is the blood vessel that carries oxygenated blood from the lungs to the heart, while the aorta carries blood from the heart to the body, the vena cava returns deoxygenated blood to the heart, and the pulmonary artery carries deoxygenated blood from the heart to the lungs.

What is the function of the coronary arteries?

• To supply oxygen-rich blood to the lungs

• To remove waste products from the blood

• To supply oxygen and nutrients to the heart muscle

• To carry blood away from the heart to the body

Answer explanation

The coronary arteries are responsible for supplying oxygen and nutrients to the heart muscle, ensuring it functions effectively. This is crucial for maintaining a healthy cardiovascular system.

The heart is part of a double circulatory system. This means:

• Blood passes through the heart twice in one complete circulation.

• Blood flows only once through the heart.

• The heart pumps blood at double the rate of a single circulatory system.

• The heart has two chambers.

Answer explanation

In a double circulatory system, blood passes through the heart twice during one complete circulation: once to the lungs for oxygenation and once to the rest of the body. This distinguishes it from a single circulatory system.

Which side of the heart contains oxygenated blood?

• Right side

• Left side

• Both sides equally

• Neither side

Answer explanation

The left side of the heart contains oxygenated blood, which it receives from the lungs and pumps to the rest of the body. In contrast, the right side contains deoxygenated blood returning from the body.

The group of cells that act as the heart's natural pacemaker are located in the:

• Left ventricle

• Right ventricle

• Left atrium

• Right atrium

Answer explanation

The heart's natural pacemaker, known as the sinoatrial (SA) node, is located in the right atrium. It generates electrical impulses that regulate the heartbeat, making the right atrium the correct answer.

What is the main function of heart valves?

• To pump blood into the arteries

• To prevent the backflow of blood

• To exchange gases between blood and tissues

• To regulate the heart

Answer explanation

The main function of heart valves is to prevent the backflow of blood, ensuring it flows in one direction through the heart and into the arteries, which is crucial for maintaining efficient circulation.

Which blood vessel carries deoxygenated blood from the body to the heart?

• Pulmonary vein

• Vena cava

• Aorta

• Pulmonary artery

Answer explanation

The vena cava is the blood vessel that carries deoxygenated blood from the body back to the heart. In contrast, the pulmonary vein carries oxygenated blood from the lungs to the heart.

What feature of capillaries allows efficient exchange of gases?

• Thick walls

• Large lumen

• Walls one cell thick

• Presence of valves

Answer explanation

The walls of capillaries are one cell thick, allowing for efficient gas exchange. This thin barrier facilitates the diffusion of oxygen and carbon dioxide between blood and surrounding tissues.