Question

justify your answer ​

Answer 1

$\bold{Answer\;:-}$

Query : Veins are thin walled and have valves.

Justification : Veins transport deoxygenated blood to the heart (the blood in no longer under pressure). Pulmonary vein is an exception, it conveys oxygenated blood from the lungs to the left atrium of the heart. Veins contain valves which prevent the backflow of the blood.

Walls of the arteries and veins consist of three layers :-

- Tunica interna - the innermost layer consisting of endothelium and an elastic membrane.

- Tunica media - a middle layer of smooth in voluntary muscle and elastic fibres.

- Tunica externa - an external layer consisting of loose connective tissue.

$\bold{Hope\;it \; helps\;!}$