Mesencephalon

In biological anatomy, the Mesenchephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. The mesencephalon caudally adjoins the pons and rostrally adjoins the diencephalon.

In mature human brains, the mesencephalon becomes the least differentiated from both its developmental form and within its own structure, among the three vesicles. The mesencephalon is considered part of the brain stem or the midbrain. The substantia nigra is closely associated with motor system pathways of the basal ganglia.

The mesencephalon is archipallian in origin, meaning its general architecture is shared with the most ancient of animals. Dopamine produced in the subtantia nigra plays a role in motivation and habituation of species from humans to the most elementary animals such as insects.

Organization

• mesencephalon
  • tectum
    • inferior colliculi
    • superior colliculi
  • cerebral peduncle
    • midbrain tegmentum
    • crus cererbri
    • substantia nigra
  • pretectum

• list of regions in the human brain