part_of part of part of develops_from develops from develops from has developmental contribution from has developmental contribution from has potential to develop into has potential to develop into hindbrain posterior neural tube rhombencephalon neural crest future brain presumptive structure presumptive hindbrain future hindbrain embryonic rhombencephalon rhombencephalon presumptive rhombencephalon The rhombencephalon (or hindbrain) is a developmental categorization of portions of the central nervous system in vertebrates. The rhombencephalon can be subdivided in a variable number of transversal swellings called rhombomeres. In the human embryo eight rhombomeres can be distinguished, from caudal to rostral: Rh7-Rh1 and the isthmus (the most rostral rhombomere). A rare disease of the rhombencephalon, 'rhombencephalosynapsis' is characterized by a missing vermis resulting in a fused cerebellum. Patients generally present with cerebellar ataxia. The caudal rhombencephalon has been generally considered as the initiation site for neural tube closure.