Which brain surface feature forms a valley or groove?

Which brain surface feature forms a valley or groove?

• A. Sulcus
• B. Gyrus
• C. Fissure
• D. Cortex

Answer: (A)

The concept here is distinguishing brain surface landmarks. A sulcus is the shallow groove or valley that sits between gyri on the cerebral cortex, giving the brain its folded appearance. A gyrus, by contrast, is the raised ridge between grooves. A fissure is a deeper cleft that separates larger regions, such as the longitudinal fissure between hemispheres. The cortex refers to the entire outer layer of neural tissue, not a specific groove. So the feature that forms a valley or groove on the brain surface is the sulcus.

The concept here is distinguishing brain surface landmarks. A sulcus is the shallow groove or valley that sits between gyri on the cerebral cortex, giving the brain its folded appearance. A gyrus, by contrast, is the raised ridge between grooves. A fissure is a deeper cleft that separates larger regions, such as the longitudinal fissure between hemispheres. The cortex refers to the entire outer layer of neural tissue, not a specific groove. So the feature that forms a valley or groove on the brain surface is the sulcus.