Thymus
From IKE
Basics
- Site of T cell maturation
- Essential for normal T cell development
- located in the midline, above the heart
- Epithelial cells are mostly radioresistant
- Bone marrow-derived cells are mostly radiosensitive
- made up of several lobules, which each contain discrete cortical (outer) and medullary (central) regions
Cortex
- consists of:
- immature thymocytes
- branched cortical epithelial cells (with which immature cortical thymocytes are related)
- macrophages - involved in clearing apoptotic thymocytes
- Thymocytes in the outer cortical cell layer are proliferating immature cells
- Thymocytes in the deeper cortical layers are mainly undergoing thymic selection
Medulla
- consists of:
- mature thymocytes
- medullary epithelial cells
- macrophages
- dendritic cells of bone marrow origin
