Learning Center > Major Bodily Systems > Lymphatic System

The lymphatic system is key to the body's immune defense system.

The lymphatic system is made up of lymph fluid, lymphatic vessels, bone marrow (the production site of white blood cells), and other structures and organs that contain lymph, such as lymph nodes, the spleen and tonsils.

The lymphatic system drains waste products from tissues, produces disease-fighting white blood cells (leukocytes) and carries the waste from the cells to the final elimination organs. Special filters along these "highways", called lymph nodes, remove infectious organisms.

Lymph. Lymph is an alkaline (pH > 7.0) fluid that is usually clear, transparent, and colorless. It flows in the lymphatic vessels and bathes tissues and organs in its protective covering. Like blood, it is slightly heavier than water.

Lymphatic vessels. Lymphatic vessels are similar to the veins of the cardiovascular system, but the vessel walls are much thinner and have more valves. Unlike the bloodstream, the lymphatic vessels travel in one direction only, from the tissues to the bloodstream.

The lymphatic vessels, like veins, have one-way valves that prevent backflow. Since there is no active pump in the lymph system, there is no back-pressure produced. Unlike the circulatory system, the lymph vessels depend largely on muscles, not the heart, to pump fluid through its vessels.

Lymph nodes. Along the lymphatic vessels there are small bean-shaped lymph nodes that serve as filters of the lymphatic fluid. Lymph nodes filter out and trap bacteria, viruses, cancer cells, and other unwanted substances, and to make sure they are safely eliminated from the body.

Leukocytes (White Blood Cells). Leukocytes circulate through the body between the lymph organs and nodes by means of the lymphatic vessels. Leukocytes can also circulate through the blood vessels.

There are two basic types of leukocytes:

• Phagocytes are cells that engulf and ingest invading organisms.
• Lymphocytes are cells that allow the body to remember and recognize previous invaders. There are two types of lymphocytes: B lymphocytes are the body's military intelligence system, seeking out their targets and sending defenses to lock onto them. T lymphocytes are like the soldiers, destroying the invaders that the intelligence system has identified.

A sluggish lymphatic system is often due to lack of exercise, but it can also be the result of excess waste or fluid in the body. When an infection is being fought in nearby tissues, lymph glands become swollen with the additional burden.

Lymph cleansing techniques:
1. Regular exercise keeps the lymphatic system from stagnating. However, if exercise cannot be performed, stretching or Yoga may help (including breathing exercises).

2. Deep breathing (a.k.a., diaphragmatic or stomach breathing) exercises should be performed to help keep the lymphatic system moving. Diaphragmatic breathing uses the diaphragm muscle ( a strong dome shaped muscle) located under our ribs and above our stomach. When we breath in, we push the muscle down, and our tummy moves forward. When we breath out, the diaphragmatic muscle moves back to resting position and our tummy moves back in. There is little or no upper chest movement.

3. A whole body massage is a great way to revive a stagnant lymphatic system.