The lymphatic system belongs to the circulatory system. This system provides one way for the blood to leave the heart, the arterial system and two ways for it to return: the venous and lymphatic pathways. The lymph system is therefore a second pathway back to the heart, parallel to the blood system.

The lymphatic system is of primary importance in transporting fat from the intestines to the blood stream, in removing and destroying toxic substances, regenerating tissues and in maintaining a healthy immune system. It is comprised of three main elements: lymph fluid, vessels and nodes working together to accomplish these functions.

Lymph Fluid

Life without water is unsustainable. Water accounts for, on average, approximately 60% of Total Body Weight. 40% is located inside the cells; 5% in the plasma of the blood; and 15% in the interstitial fluid and lymph.

Lymph is a transparent, colorless alkaline liquid slightly less viscous than blood. Lymph is 96% water. Lymph also contains: proteins, lipids, carbohydrates, enzymes, urea, minerals, hormones, some dissolved gases (e.g. carbon dioxide), cells (lymphocytes & macrophages), toxins, bacteria, body waste, and bits of cell debris, etc.

Lymph Vessels (Lymphatics)

The lymphatics originate in nearly all parts of the body as lymph capillaries. These vessels are very fine in the beginning and gradually increase in size: lymph capillaries feed into pre-collectors which connect to collectors, ducts and trunks which eventually join the major venous circulation just before reaching the heart behind the clavicles.

In contrast to the blood circulation, which uses the pumping of the heart to circulate its flow, lymph is propelled through the vessels primarily by the rhythmic contractions of tiny muscular units (lymphangions) which form the lymph collectors. The lymphatic system has a slow rhythm, low velocity and low pressure.

When stimulated, the action of the lymphangions can increase the flow through the lymphatic system by 20 - 30 times.

Lymph Nodes

The lymph vessels transport the lymph to the lymph nodes, which are soft, ovoid organs lying along the course of lymphatic vessels. They range in size from 2 - 25 mm. There can be from 400 - 700 nodes in the human body. Half of them are located in the abdomen; many are in the cervical (neck) region. The main groups of nodes are found in the major articulations of the body, with the exception of the wrists.

Lymph nodes are filtration and purification stations for the lymph. In the nodes, specific immune cells destroy foreign or unwanted substances which can then be handled by the liver and flushed out of the body via the organs of elimination (digestive apparatus, urinary tract, skin and lungs).

Lymph nodes are not only part of the lymphatic system, but are also lymphoid organs, and are linked to the immune system.