Search results
Results from the WOW.Com Content Network
The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule.
Thymus tissue is compartmentalized into cortex and medulla and each of these two compartments comprises its specific thymic epithelial cell subset. cTECs reside in the outer part- cortex, which mostly serves as a developmental site for T cells.
About 90% of T cells displays badly rearranged TCRs, they cannot reach the positive selection and they die by neglect in the cortex. [18] The rest starts to express CCR7, which is a receptor for mTEC-generated chemokine CCL21, and migrate after concentration gradient to the thymic medulla to encounter mTECs. [19]
Thymocytes that make adequate interaction with MHC complex, are survived and diverted to either CD4+ or CD8+ single positive (SP) T lymphocytes depending on the MHC molecule they encounter. These single positive cells migrate out of the cortex to the medulla, where the process continues as a negative selection. [7]
Histology of the thymus showing the cortex and medulla Minute structure of thymus. The ability of T cells to recognize foreign antigens is mediated by the T cell receptor (TCR), which is a surface protein able to recognize short protein sequences that are presented on MHC. The purpose of thymocyte development is to produce mature T cells with a ...
Hassall's corpuscles (also known as thymic bodies) are structures found in the medulla of the human thymus, formed from eosinophilic type VI thymic epithelial cells arranged concentrically. These concentric corpuscles are composed of a central mass, consisting of one or more granular cells, and of a capsule formed of epithelioid cells.
Thymus stromal cells are subsets of specialized cells located in different areas of the thymus. [1] They include all non-T-lineage cells, such as thymic epithelial cells (TECs), endothelial cells, mesenchymal cells, dendritic cells, and B lymphocytes, and provide signals essential for thymocyte development and the homeostasis of the thymic stroma.
The renal cortex, here denoted by the number 2.. The renal cortex, between the renal capsule and the renal medulla; assists in ultrafiltration; The adrenal cortex, situated along the perimeter of the adrenal gland; mediates the stress response through the production of various hormones