Transportation, Excretion
In human beings and vertebrates, the lymphatic system acts as a subsystem of the circulatory system. It also has a role to play in the transportation in human beings. Lymph is a special fluid called the tissue fluid. It plays a role in the exchange process of nutrients and gases that occurs through blood. Any excess fluid remaining in the cells and tissues is collected by the lymph and is drained into the veins, which carry blood.