The lymphatic cappillaries take up excess fluid and return it to the bloodstream; absorb and transport fats from the digestive track to the bloodstream; and defend the body against disease.
Also the lymphatic system carries certain nutients from the small bowel into the blood circulation.
Summarily, the main function of the lymphatic system is to maintain fluid balance in the body.
It is, however, also involved in the body's fight against infection by producing lymphocytes.