n.
Pale fluid that bathes tissues, maintaining fluid balance and removing bacteria.
It enters the blood system at a vein under the collarbone that it reaches via channels and ducts, being driven through them mainly by surrounding muscle activity. The lymphatic organs ( spleen and thymus ) and lymph nodes filter out bacteria and other particles the lymph takes up from body tissues. Lymph contains lymphocytes and macrophages, the primary cells of the immune system . See also lymphatic system .