Through out the body, a clear to slightly cream fluid circulates through the body tissues. Whilst freely circulating, the lymph filters the lymphatic system and it picks up bacteria, fats, excess fluid and other rejected substances. Some cuts and bruises secrete lymph instead of blood. This is a sign that you did not puncture a blood vessel and that your immune system is working well as the clear fluid lymph contains a high concentration of lymphocytes – the white blood cells, also known as anti-bodies, which readily fight any disease and infection they may come across.
The smallness of the white blood cells contained in the lymph allow the lymph to circulate freely through out the body. Other contents of lymph are proteins and red blood cells. When circulating, the lymph bathes cells with the nutrients, oxygen and proteins that they need to continue functioning well and it also takes away the toxins around the cells. Lymph helps to filter substances in and out of the blood stream.
The lymph is a core part of the lymphatic system which also includes core organs such as the spleen, bone marrow and thymus. The lymphatic system works in a similar manner to the blood circulatory system. During circulation, the lymph reach one of the many lymph nodes which in turn filter and clear out the lymph of the toxic substances it will be carrying, they also replenish the lymph with more good nutrients and oxygen to deliver to the cells in the body.