The<unk>  (or hindbrain) is a developmental categorization of portions of the central nervous system in vertebrates.
The<unk>  can be subdivided in a variable number of transversal swellings called rhombomeres. In the human embryo we can distinguish eight rhombomeres, from caudal to rostral: Rh7-Rh1 and the  isthmus (the most rostral rhombomere).
A rare disease of the<unk> , "rhombencephalosynapsis" is characterized by a missing vermis resulting in a fused cerebellum. Patients generally present with cerebellar ataxia.
Rhombencephalon
Prosencephalon
Diencephalon
Basal ganglia
Cerebral peduncle
Hypophysial fossa
Olfactory bulb
Fourth ventricle