Which vessels assist in the function of lymphatic nodes?

The lymphatic system is an essential part of the immune system, with lymph nodes playing a crucial role in filtering lymph fluid and facilitating immune responses. Veins are the correct answer because they are directly involved in returning lymph fluid back into the circulatory system.

After lymph fluid has been filtered by lymph nodes, it is transported through vessels known as lymphatic vessels which eventually connect to the venous system. The lymphatic vessels drain into larger veins, typically at the junction of the subclavian and internal jugular veins. This connection allows for the re-entry of lymph, which contains immune cells, proteins, and waste products, to be integrated back into the bloodstream.

In contrast, arteries are responsible for conveying oxygen-rich blood away from the heart, while capillaries are the smallest blood vessels, playing a key role in nutrient and gas exchange at the tissue level. Venules, like capillaries, are involved in the drainage of blood from capillary beds into veins, but they do not have a significant role in the functioning of lymph nodes specifically. Thus, veins are particularly relevant for the return of lymph fluid after it has passed through lymphatic nodes.