Question

Assertion (A): Capillaries are the thinnest blood vessels.

Reason (R): Capillaries connect the branches of arteries and veins.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

Answer 1

Both A and R are true but R is not the correct explanation of A.

Explanation:

The assertion is true because capillaries are indeed the microscopic, smallest, and thinnest blood vessels in the human body. The reason is also true because capillaries form an extensive physical network that directly connects the smallest branches of arteries (arterioles) to veins (venules). However, the reason is not the correct explanation because connecting arteries and veins is their anatomical path; they are structurally thin to facilitate the efficient diffusion and exchange of gases and nutrients with surrounding tissues.