Question

Because lymphatic vessels have three tunics (intima, media, and externa) and valves, they structurally resemble:

A) veins
B) arterioles
C) venules
D) arteries
E) all of the choices are correct

Answer 1

Lymphatic vessels structurally resemble veins because they both have three tunics - tunica intima, tunica media, and tunica externa - and are equipped with valves that ensure one-way fluid flow.

Step-by-step explanation:

The question asks which type of blood vessel lymphatic vessels structurally resemble due to their three-tunic composition and presence of valves. Because they share these structural characteristics, lymphatic vessels closely resemble veins. Both lymphatic vessels and veins have tunica intima, tunica media, and tunica externa layers and are equipped with valves that ensure the flow of fluid in one direction. Arteries and arterioles, while having the same three tunics, have thicker walls and smaller lumens due to the higher pressure of the blood flowing through them. Venules share similarities in structure with veins but are generally smaller. Hence, among the given choices, veins are the closest in structural resemblance to lymphatic vessels.