How are collecting lymphatic vessels different from veins?

• A. Collecting lymphatic vessels have fewer tunics than do veins.
• B. Collecting lymphatic vessels have thicker walls than do veins.
• C. Collecting lymphatic vessels have more internal valves than do veins.
• D. Collecting lymphatic vessels do not form branches (anastomoses); veins do form branches.

Answer: (C)

Verified step by step guidance

1. Understand the structure of collecting lymphatic vessels and veins. Both are part of the circulatory system but have different roles and structures.
2. Recognize that collecting lymphatic vessels are part of the lymphatic system, which is responsible for transporting lymph, a fluid containing white blood cells, throughout the body.
3. Note that veins are blood vessels that carry blood towards the heart, and they have a structure that includes three layers or tunics: the tunica intima, tunica media, and tunica externa.
4. Identify that collecting lymphatic vessels have more internal valves than veins. These valves are crucial for preventing the backflow of lymph, ensuring it moves in one direction towards the heart.
5. Understand that while veins can form branches or anastomoses, collecting lymphatic vessels typically do not form such branches, highlighting a structural difference between the two.