The Lymphatic System and Immunity

The lymphatic system is part of your body’s immune system. It is a network of lymph vessels that goes to almost every part of your body. If you look at a diagram of the lymphatic system, it looks a bit like the circulatory system, with branches of vessels.

The Lymph Journey

The smallest branches of the lymphatic system are the lymph capillaries that drain lymph from the tissues. Lymph is carried from the capillaries to larger lymph vessels. These vessels empty lymph into two ducts in the upper body (right lymphatic duct and thoracic duct). It then goes into the subclavian veins and joins the bloodstream again. Lymph nodes and the other lymph organs protect the body against infection.

What is lymph?

Lymph is excess fluid that leaks out of blood vessels and collects in between the cells of the body’s tissues. It then drains into the network of lymph capillaries and moves through the lymph system until it is emptied back into the bloodstream.

What is a lymph node?

Lymph nodes are bean shaped filters along the lymphatic system. Inside each node are cavities containing two types of white blood cells (lymphocytes and macrophages) which neutralise or destroy micro-organisms in lymph before it goes back into the bloodstream. These play a big part in defending the body against infection. Lymph from most tissues filters through at least one node before returning to the bloodstream.

How does lymph circulate through the body?

When you move, your muscles cause pressure on the lymph system and push it through the vessels. There are valves in the vessels that prevent lymph from flowing backwards, so it can only move in one direction. This muscle action is also how blood in your veins is moved back up your body. Your heart pumps blood outwards through the arteries and your muscles help pump it back through the veins.

What else forms part of the lymphatic system?

The tonsils and adenoids produce antibodies to destroy bacteria from food and the air.

The lacrimal gland behind the eyelid produces tears with every blink. Tears contain a protective enzyme called lysozyme that kills bacteria.

The thymus gland is located behind the breastbone (sternum) and between the lungs. This is where disease-fighting T-cells (lymphocytes) mature.

The spleen is the largest of the lymph organs. It produces antibodies and also filters out damaged red blood cells.

The popliteal nodes are behind the knees and help drain excess lymph from the legs and feet.

Lymphocytes start off as stem cells in bone marrow. The largest of the white blood cells, monocytes, are also generated in the bone marrow. These migrate from the blood into tissue spaces where they develop into scavenger cells called macrophages that ingest bacteria and dead cells.

What is an inflammatory response?

If a disease micro-organism is detected in the body’s tissues, you may get an inflammatory response, which increases blood flow and brings special cells called neutrophils to the infected area to ingest and destroy the micro-organism.

What is an immune response?

If infection isn’t dealt with effectively by the inflammatory response, the body’s immune responses may be activated. This can be in the form of an antibody response or cellular defence. Inflammatory responses depend on white blood cells called B and T lymphocytes to provide protection against future infections.

What happens during an antibody response?

White blood cells called B lymphocytes recognise foreign molecules from disease organisms (antigens) that are different from the body’s natural proteins. Antigens trigger B cells to multiply. Some develop into plasma cells which secrete antibodies, which are special proteins that inactivate the antigens.

What happens during a cellular defence?

Antigens activate T cells to multiply. Killer T cells detect antigens and attack them with proteins called lymphokines. Some of the T cells become memory T cells which may survive for many years and respond to an attempted second invasion by the same antigen. They are able to mobilise rapidly.

What is Lymphatic Drainage Massage?

This is is a type of massage that aims to assist lymphatic drainage. The technique used is a way of assisting the lymph to pump back to the main lymph vessels so it returns to the bloodstream.

As with a lot of complementary therapies, there is a list of unproven claims made by therapists. It has been used to help reduce swelling (lymphoedema) after surgery, especially cancer surgery where lymph nodes may have been removed.

If you don’t have any swelling and it hasn’t been suggested by a doctor after cancer treatment or an operation, there is no need for you to have lymphatic drainage massage. The list of claims that lymphatic drainage massage can apparently do is to fix a sluggish lymphatic system, help you to detox, regenerate, ease sinusitis, relieve pain, constipation, insomnia, cellulite and aid weight loss.

None of these claims are proven. Your muscles help move lymph along the lymphatic system so it is doing its job just fine as long as you’re able to move normally. See my post on the liver and detoxing if you don’t already know that you can’t assist the body to detox. Massage cannot help to remove cellulite or aid weight loss. Some of the gels used may hydrate the cells in the surface of the skin, giving it a firmer appearance. You can do the same thing at home with a nourishing skin cream. Neither massage nor skin creams will get rid of cellulite though.

In Conclusion

Our bodies are amazing in the way they work and they do a good job on their own, most of the time. By understanding how your body works, you should be able to make better choices when it comes to making choices about your health.