Enkephalonprosencephalon

Enkephalonprosencephalon is an obscure term that is not widely used in contemporary neuroanatomy. It appears mainly in historical or linguistic discussions as a portmanteau combining enkephalon (a variant form of encephalon, meaning the brain) with prosencephalon (the forebrain, the anterior primary brain vesicle). The phrase does not have a standardized definition in modern anatomical nomenclature.

Etymologically, enkephalon (from Greek en-, in, and kephale, head) 낟 and prosencephalon (pro-, forward, + enkephalon) would suggest a reference to the brain in relation to the forebrain, but the exact intended sense is not consistent across sources. In current terminology, the brain is referred to as the encephalon, with a well-defined division into the forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon). The enkephalonprosencephalon conflates two distinct terms that historically may have been used separately or miscopied together.

Modern usage generally avoids this compound term. When encountered, it should be interpreted from context, most likely as either a nonstandard or erroneous reference to the encephalon (the brain) or specifically to the forebrain (prosencephalon). For clarity, contemporary writers would use encephalon or prosencephalon, or describe the relevant region by its established anatomical subdivisions.

See also: encephalon, enkephalon (orthographic variants), prosencephalon, mesencephalon, rhombencephalon.