Answer
The prosencephalon becomes the forebrain, the mesencephalon becomes the midbrain, and the rhombencephalon becomes the hindbrain.
Work Step by Step
Adult brain structures include:
Forebrain - Cerebral cortex, thalamus, hypothalamus, and pineal gland.
Midbrain - Superior and inferior colliculi, reticular formation, and substantia nigra.
Hindbrain - Pons, cerebellum, and medulla oblongata.
