What are the ridges and grooves called in the human brain?

The outer portion of the cerebral hemisphere is covered by the cerebral cortex, whose surface is highly folded.

• The upward folds are called gyri (ridges), while the downward grooves are known as sulci.
• The cerebrum is the largest part of the brain, located in the forebrain, and makes up nearly four-fifths of the brain’s weight.
• A deep cleft divides the cerebrum into the right and left hemispheres, which are interconnected by a bundle of nerve fibers called the corpus callosum.
• The sulci and gyri greatly increase the surface area of the brain. Nearly two-thirds of the cortex’s surface lies hidden within sulci. When sulci are especially deep and wide, they are referred to as fissures.

The cerebral hemisphere is divided into four lobes, each with specific functions:

1. Frontal lobe
2. Parietal lobe
3. Temporal lobe
4. Occipital lobe

• The central sulcus separates the frontal and parietal lobes.
• The lateral sulcus separates the frontal and temporal lobes.
• The parieto-occipital sulcus separates the parietal and occipital lobes.