Lymphatic System Explained

 

Anatomy

The lymphatic system is a component of the circulatory system. It is comprised of lymphatic ducts; lymphatic vessels; lymphatic capillaries; lymphatic connectors, nodes and lymph as well as the spleen.
90% of tissue fluid is constantly reabsorbed by the blood capillaries; the lymph constitutes the remaining 10% of the tissue fluid that is not picked up by the blood capillaries.

Vessels of the lymphatic system are found throughout most of the body. Lymphatic capillaries permeate the body’s tissues and merge together into larger ducts, which follow the veins and arteries towards the centre of the body. These converge and eventually empty into the venous system via the thoracic and lymphatic ducts in the chest.

A

Lymph nodes are situated along the lymphatic vessels, and are concentrated in various regions of the body, such as the armpits, groin, abdomen and neck. They act as filters and produce cells that are part of the immune response.

The fluid passing through the lymphatic system is called lymph. It is comprised of white blood cells, waste products such as thick mucus, dead blood cells, pathogens, and cancerous cells) and water.

Function

The primary role of the lymphatic system is to remove excess fluid, molecules and particles from the body’s interstitial space. A significant percentage of the proteins and water that pass from the capillaries to body tissue is not directly taken back up by the venous system, and must instead by removed by the lymphatic system.

The lymphatic system also takes up products of tissue breakdown. As the lymph returns to the venous system, it must pass through the lymph nodes, where bacteria, viruses and other particles are removed. The lymph nodes act like mini incinerators, where they kill pathogens and trap cancer cells and slows down the spread of cancer until they are overwhelmed by it.

B

The lymphatic system lacks a central, heart-like propulsion mechanism. Instead, lymph movement arises from peripheral mechanisms, including contraction of the muscles of the body, contraction of muscles that sound the larger lymphatic vessels, and valves that prevent backflow.

Problems

When the lymph vessels are unable to transport lymph fluid back into circulation it accumulates, resulting in swelling and thickening of the skin. This build-up of protein-rich lymph fluid is known as lymphedema. Once this condition occurs, the swelling may increase if an effective treatment program is not initiated.

Images A & B used on this page by kind permission from; http://www.lymphedemapeople.com/