Lymphocytes

Lymphocytes. Original image is 3,200 x 3,200 pixels.

Lymphocytes are white blood cells involved in the immune response, so-called because of their association with lymph tissue. There are two main kinds, T-Cells that mature in the Thymus and B-Cells that mature in the Bone marrow (originally called B-Cells because they were found to mature in the Bursa of Fabricius, an organ present in birds).