Question

Given alongside is a diagram of the external features of the heart.
(i) Name the parts ‘1’ to ‘7’.
(ii) What happens if the coronary artery gets an internal clot?
(iii) Which type of blood does part ‘5’ carry?
(iv) Mention one structural difference between part ‘5’ and ‘4’.

Answer 1

(i)
1. Aorta
2. Left atrium
3. Left ventricle
4. Dorsal aorta
5. Inferior vena cava
6.Superior vena cava
7. Pulmonary artery.
(ii) If the coronary artery gets an internal clot, the corresponding part of the heart does not get its blood supply. This will result in loss of contraction or even death of the cardiac cells resulting in a heart attack or coronary arrest which may prove to be fatal.
(iii) Part ‘5’ which is the inferior vena cava carries deoxygenated blood which is rich in CO₂ and metabolic wastes.
(iv) Part ‘5’ is more muscular and the lumen is narrow while part ‘4’ is less muscular and the lumen is wider.