The Pons and Cerebellum were derived from which embryonic brain division?

• A. Telencephalon
• B. Diencephalon
• C. Mesencephalon
• D. Metencephalon

Answer: (D)

During brain development, the hindbrain (rhombencephalon) divides into two secondary vesicles: metencephalon and myelencephalon. The pons and cerebellum come from the metencephalon, with the pons forming ventrally and the cerebellum developing from dorsal regions of the same vesicle (the rhombic lip contributes cerebellar neurons). The other divisions arise from different vesicles: the forebrain splits into the telencephalon (cerebral hemispheres, related structures) and diencephalon (thalamus, hypothalamus, etc.), while the midbrain remains the mesencephalon, and the medulla originates from the myelencephalon. Hence, the pons and cerebellum are derived from the metencephalon.