20330B

20330B
Caption: Human T lymphocyte (T cell). Lymphocytes are involved in the specific immune response and are composed mainly of precursor T cells and B cells (pre-T cells and pre-B cells). Pre-T cells and pre-B cells are subsets of lymphocytes that originate in the red bone marrow from hematopoietic stem cells. Pre-T cells circulate in the blood before migrating to the thymus where they develop into specialized cells (helper T cells and killer T cells) that are able to identify antigens and infected tissue.
Magnification*: x2,600
Type: SEM
Copyright 2000 Dennis Kunkel Microscopy, Inc.
Keywords: 20330B,human body,blood,human,white blood cell,T lymphocyte,T cell,helper T cell,killer T cell,pre-T cell,leukocyte,T-lymphocyte,SEM