What are examples of lymphoid tissue?
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.
The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body. The lymphatic system primarily consists of lymphatic vessels, which are similar to the circulatory system's veins and capillaries.
- Lymph nodes are major sites of B and T lymphocytes, and other white blood cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles and cancer cells. Lymph nodes do not have a detoxification function, which is primarily dealt with by the liver and kidneys.
- The lymphatic system is the site of many key immune system functions. It is responsible for the removal and filtration of interstitial fluid from tissues, absorbs and transports fatty acids and fats as chyle from the digestive system, and transports many of the cells involved in immune system function via lymph.
- The lymphatic system is a network of very small tubes (vessels) that drain lymph fluid from all over the body. The major parts of the lymph tissue are located in the bone marrow, spleen, thymus gland, lymph nodes, and the tonsils.
Primary lymphatic organs are where lymphocytes are formed and mature. They provide an environment for stem cells to divide and mature into B- and T- cells: There are two primary lymphatic organs: the red bone marrow and the thymus gland.
- The mucosa-associated lymphoid tissue (MALT), also called mucosa-associated lymphatic tissue, is a diffuse system of small concentrations of lymphoid tissue found in various submucosal membrane sites of the body, such as the gastrointestinal tract, oral passage, nasopharyngeal tract, thyroid, breast, lung, salivary
- Secondary follicles: lymphoid follicles with a germinal centre. These mostly contain B-cells. The nodes are covered by a capsule of dense connective tissue, and have capsular extensions, of connective tissue, called the trabeculae, which provide support for blood vessels entering into the nodes.
- The lymphatic system has three functions:
- The removal of excess fluids from body tissues.
- Absorption of fatty acids and subsequent transport of fat, chyle, to the circulatory system.
- Production of immune cells (such as lymphocytes, monocytes, and antibody producing cells called plasma cells).
Updated: 17th October 2018