Question

5. The figures given below show diagrammatio cross
sections of three kinds of blood vessels
B.
A
(a) Identify the blood vessels A, B and C,
(b) Name the parts labelled 1-4.
(C) Mention two structural differences between A and B.
(d) Name the kinds of blood that flow through A and through
B respectively,
(e) In which one of the above vessels referred to in (a)
above does the exchange of gases actually take
place?​

Answer 1

Answer:

(a) A- Vein, B-Artery, C-Capillary

(b)

1 - External layer made of connective tissue

2 - Lumen

3 - Middle layer of smooth muscles and elastic fibres

4 – Endothelium

(c) 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 back flow of blood.

(d) A (Vein) - deoxygenated blood, B (Artery)- oxygenated blood

(e) At the capillary level the actual exchange of gases takes place.