label: thymus corticomedullary boundary
label_lc: thymus corticomedullary boundary
description: "The dense region demarcating the thymus medulla from the surrounding cortex that is characterized by numerous blood vessels (predominantly arterioles) with some perivascular connective tissue, mature and immature T lymphocytes, dendritic cells, variable numbers of perivascular B-lymphocytes and plasma cells; site of entry of bone marrow stem cells and exit of mature, functional T cells."