Brain of the human embryo

The developing parts of the brain, the first and the second ventricles labeled red and orange, respectively, give rise to the telencephalon and diencephalon (prosencephalon or forebrain). In this part of the brain, the bases of the optic stalks beginning on diencephalon are visible. The third ventricle, which gives rise to the mesencephalon is marked in yellow. Caudal to this is the rhombencephalic isthmus (the rootlets of the trochlear nerve arising from this area) and the metencephalon (blue) lies more caudally. In this part of the model, the area where the cerebellum is developing is visible. The myelencephalon and cranial nerves (facial nerve, glossopharyngeal nerve, hypoglossal nerve, oculomotor nerve, and accessory nerve) are shown in purple. A fragment of the spinal cord is shown in grey.