The Lymphatic System is the part of the immune system comprising a network of conduits called lymphatic vessels that carry a clear liquid called lymph (water) unidirectionally toward the heart. The blood does not directly come in contact with the parenchymal cells and tissues in the body but constituents of the blood first exit the microvascular exchange blood vessels to become interstitial fluid which comes into contact with the parenchymal cells of the body.

Lymph is the fluid that is formed when interstitial fluid enters the initial lymphatic vessels of the lymphatic system. The lymph is then moved along the lymphatic vessel network by either intrinsic contractions of the lymphatic passages or by extrinsic compression of the lymphatic vessels via external tissue forces such as contractions of the skeletal muscles. Any exercise that speeds up the heart and opens up the arteries, capillaries and/or veins will strengthen the lymphatic system.

Lymphoid tissue is found in many organs particularly the lymph nodes and in the lymphoid follicles associated with the digestive system such as the tonsils. The system also includes all the structures dedicated to the circulation and production of lymphocytes which includes the following;

1.     Bone Marrow.

Makes red and white blood cells.

2.     Spleen.

Filters blood and removes abnormal blood cells by phagocytosis.

Stores iron from worn out blood cells.

Activates B cells and T cells in response to antigens in the blood.

3.     Thymus.

Produces hormones that stimulate the production of T cells which are

infection fighting cells.

4.     Tonsils.

First line of defense against ingested pathogens.

 

THREE (3) MAIN FUNCTIONS

1.   The lymph circulation returns to the blood stream vital substances, chiefly proteins that have leaked out of the capillaries along with accumulated interstitial fluid.

2.     Intestinal lymphatics are the pathways for the absorption of digested lipids (fats) from the alimentary canal.

3.   The lymphatic system protects the body against disease producing microorganisms and other invading foreign substances in two (2) ways;

A) Phagocytosis-

Macrophages lining the channels of lymph nodes phagocytize and digest foreign matter.

          B)  Immune Response Trigger-

                   B cell system, which is triggered by proteins aka antibodies.       

                   Most effective against acute bacterial infection.

                   Most effective against viruses and viral re-infection.

                   T cell system, triggered by specialized cells sensitized to foreign substances.

                   Most effective against bacteria causing chronic infections, fungi & malignant cells.