Lymphatic system

The lymphatic system is a system of vessels and lymph nodes that is separate division from the circulatory system and operates by returning fluid, protein and fat to the blood. The lymphatic system plays a pivotal role in the immune response.

Components of the lymphatic system

Lymph vessels

These are thin- walled vessels that are found throughout the body, and have the role of carrying fluid and proteins that have been collected in the body tissues and fats absorbed in the intestine into the general circulation. These components that are in the fluid form travelling through the lymphatic system are referred to the lymph. Lymph vessels contain valves that prevent the backflow of the lymph. The lymph periodically gets filtered through the lymph nodes whilst travelling through the general circulation, before  eventually ending up in the large vessels going to the heart.  Water is squirted out of the capillaries in the body tissues and hence it is returned to the general circulation to travel around the body again.

Lymph nodes

Lymph nodes are small masses of lymph tissue contain phagocytes and T and B lymphocytes. Lymph fluid passing through the lymph nodes are filtered by the phagocytes and the lymphocytes are able to  multiply to activate a specific immune response. The multiplication of the lymphocytes causing swelling in the lymph nodes, which is why when in individual is sick they often have swollen glands. Lymph nodes are found all throughout the body such as in the spleen, tonsils and appendix.

See also