The main and largest component of the human brain is the cerebrum. The cerebrum consists of two main parts: the cerebral cortex, an outer layer with wrinkles or folds known as gyri and shallow grooves called sulci, and a deeper region beneath it. The cerebrum divides into two distinct hemispheres and contains five different lobes: the frontal, parietal, temporal, occipital, and insula. The central sulcus separates the frontal and parietal lobes and two functionally important gyri — the precentral and postcentral gyrus.
The lateral sulcus separates the temporal lobe from the frontal and parietal lobes, whereas the parieto-occipital sulcus separates the parietal and occipital lobes. The smallest lobe, the insula, is present deep in the lateral sulcus. The end of the occipital lobe and the separation of the cerebrum from the cerebellum are marked by a deeper sulcus known as the transverse cerebral fissure.
The cranial cavity protects the cerebrum perfectly, with the frontal lobes fitting in the anterior cranial fossa, the temporal and parietal lobes in the middle cranial fossa, and the occipital lobes present superior to the posterior cranial fossa.
