Question

Assertion: The arteries are not collapsible when they are empty.
Reason: Arteries are situated deeply in the body.

• A. Both the assertion and reason are true and the reason is the correct explanation for the assertion
• B. Both the assertion and reason are true but the reason is not the correct explanation for the assertion
• C. Assertion is true but the reason is false
• D. Reason is true but the assertion is false

Answer 1

The correct option is B Both the assertion and reason are true but the reason is not the correct explanation for the assertion

The arteries and veins have three layers in their walls namely tunica externa, tunica media and tunica interna from outwards to inwards respectively.
The outer layer tunica externa and inner layer tunica interna have a comparable thickness in arteries and veins. But the middle layer tunica media is thicker in the arteries than the veins. There are more muscle fibres in the tunica media layer of the arteries than the veins. The thick muscular wall of arteries makes it non-collapsible even when they are empty. But the veins are collapsible as they have thin walls.

Arteries carry oxygenated blood under considerable pressure. So any damage to these blood vessels can result in immediate blood loss. Therefore, arteries are deeply located in the body to prevent any damage from outside. The veins, on the other hand, are superficially situated as the blood flows with considerably low pressure in them than the arteries.