The lymph capillaries are separate from the circulatory system They have closed ends and large pores that allow large molecules to pass through Larger molecules that are not able to pass through the capillary wall enter the lymphatic system as lymph Small valves in the vessel walls are the entry point to the lymphatic system

lymphoid tissue, cells and organs that make up the lymphatic system, such as white blood cells (leukocytes), bone marrow, and the thymus, spleen, and lymph nodes. Lymphoid tissue has several different structural organizations related to its particular function in the immune response. The most highly organized lymphoid tissues are in the thymus and lymph nodes, which are well-defined.

The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid organs, and lymphoid tissues.