Immune/lymphatic system – this is a circulatory system for removing waste products and fighting infection. Related organs include the tonsils, thymus, spleen, lymph nodes (and possibly the Appendix). If this system is not working properly the health of the body quickly deteriorates. Cancer can spread through the body when it gets into the lymphatic system – the very system that exists to fight and remove infections. Bacteria in the gut also play an important part in the body’s ability to fight infection.
The cerebrospinal fluid is an important circulatory system associated with the lymphatic system. The brain produces about 500 ml of cerebrospinal fluid a day, and it is used as a protective layer around the brain and spine. It removes waste and plays a large part in keeping the brain tissues in a healthy state (reducing the likelihood of strokes and Alzheimer’s). The pressure of the fluid around the brain results in the brain being almost weightless. Any imbalances in the static fluid pressure can be very painful or fatal (water on the brain or hydrocephalus). Some advanced yoga techniques, such as in Kriya Yoga, actively work to improve the circulation of the cerebrospinal fluid and hence help in keeping the brain free of toxins.