Middle part of the brainstem composed of the pons and the cerebellum.
meta (after), enkephalos (brain). The Pons?.
The metencephalon joins the myelencephalon away from you. It is much thicker than the myelencephalon, which can be distinguished by its thin roof. Walls of the myelencephalon have swellings called neuromeres. The walls and floor of the myelencephalon will become the medulla. The cavities of metencephalon and myelencephalon will become the fourth brain ventricle and will fill with cerebrospinal fluid.
The metencephalon is a developmental categorization of portions of the central nervous system. The metencephalon is composed of the pons and the cerebellum; contains a portion of the fourth ventricle; and the trigeminal nerve (CN V), abducens nerve (CN VI), facial nerve (CN VII), and a portion of the vestibulocochlear nerve (CN VIII).