Cerebellum "microzones" or "microcompartments". The cerebellum is located in the posterior cranial fossa. The fourth ventricle, pons and medulla are in front of the cerebellum. It is separated from the overlying cerebrum by a layer of leathery dura mater, the tentorium cerebelli; all of its connections with other parts of the brain travel through the pons. Anatomists classify the cerebellum as part of the metencephalon, which also includes the pons; the metencephalon is the upper part of the rhombencephalon or "hindbrain". Like the cerebral cortex, the cerebellum is divided into two hemispheres; it also contains a narrow midline zone (the vermis).
Antigen transfer in the thymus in thymic medulla, namely clonal deletion ("recessive tolerance") and T Regulatory cells selection ("dominant tolerance") which force autoreactive T cells to apoptosis or skew them into suppressor T regulatory cells (TRegs), respectively, in order to protect body against manifestations of autoimmunity. These processes are mediated especially by unique subset of stromal cells called Medullary thymic epithelial cells (mTECs) via presentation of Tissue restricted antigens (TRAs) that represent self tissues from almost all parts of the body. mTECs are not only capable to present TRAs as efficient APCs. They are also potent in production of these TRAs via unique process called