Cerebrum originates from which primary brain vesicle?

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

Answer: (A)

Cerebrum forms from the telencephalon, the part of the forebrain that expands to create the cerebral hemispheres. Early in development, the forebrain (prosencephalon) splits into two regions: the telencephalon and the diencephalon. The telencephalon grows and becomes the cerebrum, including the cerebral cortex and related structures. The diencephalon stays to form deeper structures such as the thalamus and hypothalamus. The other options correspond to different brain regions: the mesencephalon becomes the midbrain; the myelencephalon becomes the medulla; these originate from the hindbrain (rhombencephalon).