What is the lymph system, and what are lymph nodes? The lymph system is essentially the "housekeeping system" of the body. It is a network of vessels (tubes), which connect the lymph nodes. These nodes can vary in size, but are normally up to about 2 centimeters in width. They contain cells that clear bacteria and other foreign debris from the body. Lymph is a watery liquid that flows between cells in the body, picking up foreign debris and taking it into the lymph node for filtering. From the lymph node, the debris may pass through several more nodes in the system before being dumped into the bloodstream to ultimately be cleared by the liver. The lymph system flows throughout the body, and also includes the spleen and thymus gland. What is a lymphocyte? Lymphocytes are a type of white blood cell. These cells (called B cells and T cells) are important in fighting infection and ... read more on Cutaneous T Cell Lymphoma (CTCL): The Basics