Vasa vasorum . a. provide oxygen and nutrients to the innermost region of large vessels b. are a convincing sign of atherosclerosis and venous disease of the lower limb c. are composed of wide, leaky capillaries, and occur in bone marrow and the spleen d. is a rare genetic disorder in which systemic veins actually carry blood away from the heart e. are small vessels within the tunica externa of large arteries and veins

Are small vessels within the tunica externa of large arteries and veins. (Ans E).

Explanation:

Vasa vasorum: It is defined as a complex system of small blood vessels that helps to provide the larger arteries and veins' walls. It is 3 different types in structure:

1) Internae: It is obtained from the artery lumen and later divide into the vessel wall.

2) Externae: It is obtained from the artery branches.

3) Vasorae: It is obtained within the artery vessel wall then leave into the lumen.

Vasa vasorum helps to provide nourishment which is necessary for growth and supply of blood for tunica media of large vessels and tunica adventitia.

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