What is the main reason the cerebral cortex appears gray rather than white?

• A. It has fewer neurons than other brain regions
• B. It contains more glial cells than neurons
• C. It is primarily composed of cell bodies rather than myelinated axons
• D. It is more vascularized than white matter

Answer: (C)

The color difference comes from what's inside the tissue. The cerebral cortex is packed mainly with neuronal cell bodies and their dendrites, with relatively little myelin around them. That cellular content, including the bodies themselves and the surrounding glial cells, gives the cortex a gray appearance. White matter, on the other hand, is dominated by myelinated axons; the myelin sheath is lipid-rich and reflects light, producing a white color. So the cortex looks gray because it is primarily made up of cell bodies rather than myelinated fibers.