The diagram shows the front view of a human heart.

Letters P, Q, R and S indicate the different chambers of the heart.

Which of the following shows the sequence in which a blood cell returning from other parts of the body passes through the four chambers of the heart?

• R-S-P-Q

• Q-S-R-P

• P-R-Q-S

• S-R-P-Q

The bar chart shows the concentration of oxygen in blood sampled at four places in the circulatory system of a human.

Which blood sample was taken from the pulmonary vein?

• A

• B

• C

• D

Coronary heart disease can be caused by all of the following factors except

• fatty deposits on the inner surface of the heart

• formation of blood clot in an artery

• a diet rich in saturated fats

• a stressful lifestyle

What causes the sounds of a heartbeat?

• The backflow of blood hitting the heart muscles.

• The closure of the semi-lunar valves, bicuspid valve and tricuspid valve.

• The flow of blood into the left and right atria.

• The return of blood into the heart from the vena cava and pulmonary vein.

Identify the blood vessel labelled B.

• Aorta

• Pulmonary artery

• Pulmonary vein

• Vena cava

What is the function of the blood vessel labelled D?

• To transport blood from the heart to the lungs

• To transport blood from the heart to the rest of the body.

• To transport blood from the rest of the body to the heart.

• To transport blood from the lungs to the heart.

Identify

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

Identify

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

What is the strongest (thickest) part of the heart?

• right atrium
• right ventricle
• left ventricle
• left atrium

Which blood vessels carry blood to the heart?

• capiliaries
• veins
• arteries
• arterioles