The lymphatic and circulatory systems are closely linked, but function quite differently. In the circulatory system, the blood runs in a closed system and cannot pass out of it. As well, the blood has a pump (the heart) and flows bi-directionally, both towards and away from the heart. Lymph, on the other hand, only runs in one direction towards the heart. It has no pump, so it relies on contractions of the lymphatic vessels to push the lymph along. The lymphatic system plays an important role in supporting our immune, cardiovascular and neurological systems.
Our body is made up of cells which take on nutrients and give off wastes, both to and from the ‘interstitial spaces’ (the fluid-filled space ‘between’ the cells). This exchange takes place at the ends of the blood vessels. The Latin word “lymphatics” means “absorbent”. Lymph is the fluid which has been absorbed into the lymphatic system from these interstitial spaces. The lymphatic system absorbs the lymph and later returns it to the circulation once lymph-node filtration has taken place. Afferent lymph is newly-absorbed lymph that has not yet been filtered, and efferent lymph is that which has been filtered. Lymph nodes occur in clusters along the lymphatic vessels and are most abundant in the lower abdomen, neck and armpits.
Lymphatic vessels extend throughout the body typically in close association with the blood vessels. The only places there are no lymph vessels are the central nervous system, brain, retina and cornea of the eye, skin, hair, nails and cartilage. While there are no lymphatic vessels in the brain or central nervous system, lymphatic vessels are connected to the neurological system via nerves. Lymphatic vessels consist of capillaries, collecting vessels, and ducts.
Other components of the lymphoid organs include the spleen, thymus gland, thyroid gland, lung, diaphragm, colon (particularly the caecal patch), tonsils, and the Peyer’s patches of the intestine.
An average human body weighing 65 kg contains approximately 12 litres of interstitial fluid and produces 8-12 litres of lymph each day. Of that, 4-8 litres are absorbed by the lymph nodes and the remaining 4 litres is returned to the blood.
To help move the lymph along more efficiently, drink plenty of pure water (half your weight in ounces daily), have Epsom salt baths 2-3 times/week (rinse well when done so toxins don’t reabsorb), do rebound exercise (running or jumping), maintain regular well-formed bowel movements (at least once/day…1 rounded TBSP/day of plain psyllium husks in water helps this), have regular massages, and try dry brushing 1-2 times/week (natural-bristled brush and stroke towards the heart, then rinse).