Cerebral sulci

The grooves or depressions found on the outer layer of the brain, known as the cerebral cortex, are called cerebral sulci.

The cerebral cortex consists of gray matter and encompasses the white matter tracts and inner deep subcortical nuclei. Due to its extensive surface area, the cerebral cortex is folded into various grooves and raised areas referred to as cerebral sulci and gyri. These folds enable the cerebral cortex to fit within the limited space inside the cranium.

The primary cerebral sulci, such as the central sulcus, the lateral sulcus, and the parieto-occipital sulcus, play a role in dividing the brain into four main lobes. The central sulcus separates the frontal lobe at the front from the parietal lobe at the back. The lateral sulcus separates the temporal lobe below from the frontal and parietal lobes above. The parieto-occipital sulcus, most prominently visible on the inner surface of the brain, separates the occipital lobe at the back from the parietal lobe at the front.

When observing the outer or SUPEROLATERAL SIDE OF THE BRAIN, there are several important cerebral sulci. On the frontal cortex specifically, we can identify the pre-central sulcus, along with the superior and inferior frontal sulci. In the parietal lobe, notable sulci include the post-central sulcus and intra-parietal sulcus. The lateral sulcus and its posterior ramus separate the temporal lobe below from the frontal and parietal lobes above. Furthermore, the temporal lobe contains the superior and inferior temporal sulci.

On the MEDIAL OR INNER SIDE OF THE BRAIN, extensions of the pre and post-central sulci can be seen, enclosing the paracentral lobule. In the central region, the callosal sulcus separates the corpus callosum from the overlying cingulate gyrus. The cingulate gyrus is additionally bordered by an overlying cingulate sulcus. Towards the posterior region, a distinct parieto-occipital sulcus separates the occipital lobe from the parietal lobe. Within the occipital lobe, the calcarine sulcus divides it into the cuneate and lingual gyri.

On the UNDERSIDE OF THE CEREBRUM, the frontal lobe contains an olfactory sulcus that houses the olfactory tract and bulb, alongside numerous orbital sulci and gyri. As we move towards the back, the medial areas of the temporal and occipital lobes feature the rhinal and collateral sulci, while the occipitotemporal sulcus is situated laterally.