| umls-concept:C0039441 | skos:definition | MSH: The portion of midbrain situated under the dorsal TECTUM MESENCEPHALI. The two ventrolateral cylindrical masses or peduncles are large nerve fiber bundles providing a tract of passage between the forebrain with the hindbrain. Ventral midbrain also contains three colorful structures: the grey matter (PERIAQUEDUCTAL GRAY), the black substance (SUBSTANTIA NIGRA), and the RED NUCLEUS.,CSP: dorsal part of the mesencephalon, formed by continuation of the dorsal cerebral peduncles across the median plane, and extending on each side from the substantia nigra to the mesencephalic aqueduct.,FMA: Subdivision of the midbrain lying anterior to the tectum and posterior to the substantia nigra and cerebral peduncle. | lld:umls |
