What does the structure of a lymph vessel look like?

The structure of a lymph vessel is similar to that of a blood vessel, but with some key differences.

1. Endothelial cells: Lymph vessels are lined with a single layer of endothelial cells, which are thin, flattened cells that form the inner lining of the vessel. Endothelial cells in lymph vessels are specialized to transport lymph and immune cells from the tissues into the bloodstream.

2. Basement membrane: The endothelial cells are surrounded by a basement membrane, which is a thin layer of connective tissue that provides support and structure to the vessel.

3. Tunica adventitia: The outermost layer of the lymph vessel is the tunica adventitia, which is a layer of connective tissue that contains collagen and elastin fibers. The tunica adventitia provides strength and flexibility to the vessel.

4. Valves: Lymph vessels contain one-way valves that prevent the backflow of lymph. These valves are located at regular intervals along the vessel and they open and close in response to the pressure gradient within the vessel.

5. Lymphatic capillaries: Lymph vessels begin as lymphatic capillaries, which are small, blind-ended vessels that collect lymph from the tissues. Lymphatic capillaries are located in close proximity to blood capillaries and they allow the exchange of fluids, nutrients, and immune cells between the blood and the lymph.

Lymph vessels are an important part of the immune system and they play a crucial role in maintaining fluid balance in the body.