① cortex: thymic epithelial cell(epithelial reticular cell subcapsular epithelial cell /flattened /secret B 2-microglobulin, thymosin and thymopoietin interdigitation dendritic cell /more processes /MHC antigen ---thymocyte: different stages of LC large LC( prethymocyte: superfacial cortex common thymocyte: deep cortex-85-90%①cortex: ---thymic epithelial cell(epithelial reticular cell): subcapsular epithelial cell: /flattened /secret β 2 -microglobulin, thymosin and thymopoietin interdigitation dendritic cell: /more processes /MHC antigen ---thymocyte: different stages of LC large LC( prethymocyte): superfacial cortex common thymocyte: deep cortex- 85-90%