Question

The figures given below show diagrammatic cross sections of three kinds of blood vessels.

1. Identify the blood vessels A, B and C.
2. Name the parts labelled 1-4.
3. Mention two structural differences between A and B.
4. Name the kinds of blood that flow through A and through B respectively.
5. In which one of the vessels referred to in (a) above does the exchange of gases actually take place?

Answer 1

1. A - Artery, B - Vein, C - Capillary
2. 1. Tunica Externa
   2. Lumen
   3. Tunica media
   4. Endothelium
3. An artery has thick muscular walls and a narrow lumen. It does not have any valve.
   A vein, on the other hand, has thin muscular walls and a wider lumen. It has valves to prevent backflow of blood.
4. A (Artery) - oxygenated blood, B (Vein) - deoxygenated blood.
5. At the capillary level, the actual exchange of gases takes place.