The Cerebrum was derived from which embryonic brain division?

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

Answer: (A)

Understanding this question starts with how the forebrain develops. The forebrain (prosencephalon) splits into two vesicles: the telencephalon and the diencephalon. The cerebrum, which includes the cerebral hemispheres and their cortex, arises from the telencephalon. The diencephalon, by contrast, becomes structures like the thalamus and hypothalamus. The other two divisions listed—mesencephalon and metencephalon—form the midbrain and the hindbrain structures (pons and cerebellum), not the cerebrum. So the source of the cerebrum is the telencephalon.