Question

Give reason for the following (a) arteries are thick walled blood vessels (b) veins are thin wall blood vessels (c) veins have valves in thin

Answer 1

(a) The arteries are “thick walled blood vessels” that carry the oxygenated ‘blood’ from the ‘heart to the other parts’ of the body, the heart pumps blood under high pressure and hence to withstand this pressure the ‘arteries are thick-walled’.  

(b) The ‘veins carry blood from other parts’ of the body to the arteries the organs does not pump the blood and hence the pressure is lower and therefore the veins are thin walled.  

(c) The valves in the veins are thin because they handle very less pressure of blood that flows from different organs to the heart.  

Answer 2

Answer:

a) Arteries carry deoxygenated blood from the heart to the different parts of the body. Blood emerges from heart under high pressure. In order to withstand this pressure ,arteries have thick walls.

b) Veind carry deoxygenated blood from the body parts back to the heart. Blood flowing through the veins is not under high pressure. Therefore they have thin walls.

c) veins have valves in them to prevent back flow of blood. This prevents the mixing of oxygenated blood and deoxygenated blood.