Lymphocyte

Lymphocytes are a type of white blood cell (or leukocyte). They help an organism to fight infections. They occur in the immune system of all vertebrates.^[1] All lymphoctes have a large, blob-like nucleus.

Lymphocytes can be divided into three main types:

• large granular lymphocytes: these are part of the innate immune system, and are natural killer cells.
• small lymphocytes: these lymphocytes are the main agents of the acquired immune system. The two main types are:
  • T cells and
  • B cells.

1. ↑ "Dorlands Medical Dictionary:lymphocyte". Retrieved 2009-01-27.