Final answer:
The correct spelling is 'medulla,' which is part of the embryonic brain and is involved in processing cranial nerve information.
Step-by-step explanation:
The term that is spelled correctly is medulla. The medulla, also referred to as the myelencephalon in the embryonic brain, contains significant white matter on its exterior and continues into gray matter regions responsible for processing cranial nerve information. The term reflects the continuity with the white matter of the spinal cord, and its gray matter is part of the tegmentum, which is extended from the midbrain and pons.