The Lymphatic system

What is the lymphatic system?

Is a system where tissue fluid that does not re-enter the blood capillary can enter and be transported to then re-join the blood in the veins nearer the heart. 

How is the tissue fluid transported?

Blind ending lymph vessels, containing lymph (which contains the tissue fluid), are compressed due to body movements which therefore moves the lymph along and is directed by the semi-lunar valves.

What are lymph nodes?

At intervals along the lymph vessels are lymph nodes. These lymph nodes contain huge numbers of macrophages (phagocytes) and lymphocytes which produce antibodies in response to any bacteria, virus or other foreign material.