# 69 Structure and function of the heart
The function of the heart is to pump blood around the body. The right ventricle pumps blood to the lungs and the left ventricle pumps blood to the rest of the body.
Heart's function
- Blood circulation
- Blood in the right ventricle (RV) is pump to the lungs
- Blood from the lungs flows back into the left atrium (LA) and then into the left ventricle (LV).
- Blood in the LV is pumped through the body (except for the lungs)
- Blood returns to the heart where it enters the right atrium (RA).
- Muscular contraction
The heart’s muscle is constantly active, so it needs its own blood supply, through the coronary artery, to provide it with oxygen and glucose.
- Working of the valves
Animation:
Heart Contraction and Blood Flow
How the heart pumps blood
Try this
1.On a copy of the diagram of the double circulatory system, labell:
i) The 4 main blood vessels (4 marks)
ii) The chambers of the heart (4 marks)
iii) The 2 valves shown (2 marks)
2.State 2 differences in composition between blood leaving the right ventricle and blood entering the left atrium. (2 narks)
1.On a copy of the diagram of the double circulatory system, labell:
i) The 4 main blood vessels (4 marks)
ii) The chambers of the heart (4 marks)
iii) The 2 valves shown (2 marks)
2.State 2 differences in composition between blood leaving the right ventricle and blood entering the left atrium. (2 narks)
Answers:
1.
1.
2.Blood leaving the right ventricle has more CO2 and less O2 than blood entering the left atrium.