This fluid is collected in tiny tubes called lymph vessels or lymph capillaries or lymph nodes and fluid is now called lymph.
Its composition is just like plasma except it lacks RBCs and large plasma proteins. Lymph returns to the blood circulation at the level of subclavian vein present below the clavicle bone.
If the formation rate of lymph exceeds the rate of its return to blood then oedema occurs (Oedema is swelling of tissues through increase of its tissue fluid volume).
1. Maintains balance of blood and tissue fluid.
2. Add lymphocytes [produced by lymph nodes, spleen (the largest lymphatic organ), thymus etc.] for the release of antibodies.
3. Some waste products are carried by it into blood.
4. Fat is absorbed in the intestine by lymph as chylomicron or fat droplets.
5. Plasma proteins and some other macromolecules synthesized by liver enter the blood through lymph.
6. It destroys the invading micro-organisms and foreign particles in the lymph nodes.