Lymphatic System Overview - Anatomy & Physiology
|
Introduction
The lymphatic system can be divided into two anatomical and functional subsets: lymphatic vessels that carry lymph around the body, and the lymphoreticular system which describes the lymphoid tissues. The lymphatic system has three functions - immune defence, removal of interstitial fluid from tissues and the transport of fats.
Primary (or central) lymphoid tissues can also be referred to as the primary lymphoid organs. Maturation of lymphocytes and (lymphopoiesis) occurs in the primary lymphoid tissues, with different tissues responsible for maturing different types of lymphocyte.The primary lymphoid tissues are:
Secondary (or peripheral) lymphoid tissues or secondary lymphoid organs provide a site for immune responses to occur and are populated by relatively mature T cells and B cells, macrophages and dendritic cells with each tissue providing a different environment.The secondary lymphoid tissues are:
- Lymph nodes
- Spleen
- Mucosal Associated Lymphoid Tissue (MALT)
- Tonsils
- Appendix/caecal pouch
- Ileal Peyer's Patch
Immune defence
This is a broad topic area.
Immune functions are covered broadly under the primary and secondary lymphoid tissues of the lymphoreticular system with further information under the immunology section.
Removal of interstitial fluid
Details can be found here.
Transport of lipids
Chylomicrons transport digested lipids, however these are too large to enter the blood stream directly and thus enter the lymphatic system before being released into the blood stream. Further details can be found here.