The cerebrum is the largest part of the brain and is derived embryologically from the telencephalon. It mainly consists of the two cerebral hemispheres (cerebral cortex) situated in the anterior and middle cranial fossae of the bony cranium, superior to the brainstem. The left and right cerebral hemispheres are partially separated by a deep longitudinal fissure, which contains a meningeal layer of dura mater called the falx cerebri.
The cerebrum consists of two types of tissue, the gray and white matter. The gray matter forms the surface of each of the cerebral hemispheres, and is comprised mainly of nerve cell bodies. It is involved with processing and cognition. The white matter on the other hand, forms the bulk of the deeper structures of the cerebrum. It is mainly comprised of glial cells and myelinated axons that join the various areas of gray matter together. Externally, the cerebrum is a highly convoluted structure. The surfaces of the two anatomically symmetrical cerebral hemispheres, which are interconnected by a white matter structure called the corpus callosum, show numerous elevations and depressions termed gyri and sulci, respectively.
Each cerebral cortex can be classified into four lobes, the frontal, parietal, temporal, and occipital lobes. These lobes are named in relation to their corresponding cranial bones, and contain various cortical association areas. Together, they work to give us an adequate perceptual interpretation and experience of our surrounding environment.
The frontal lobe is the most anterior portion of the cerebrum. It is separated from the parietal lobe by the central sulcus and from the temporal lobe by the lateral sulcus, which consists of a stem and three rami. Other important features include the precentral and the superior, middle, and inferior frontal sulci and gyri. The frontal lobe of the dominant hemisphere is mainly associated with higher intellect, personality, mood, social conduct, and language.
The parietal lobe is present between the frontal lobe anteriorly, and the occipital lobe posteriorly. It is separated from these lobes by the central sulcus and the parieto-occipital sulcus, respectively. Other important features include the postcentral gyrus and sulcus, the intraparietal sulcus, and the superior and inferior parietal lobules. The parietal lobe of the dominant hemisphere is associated with language and calculation, and with visuospatial functions on the non-dominant side.
The temporal lobe is situated beneath the frontal and parietal lobes, from which it is separated by the lateral sulcus. It includes the superior and inferior temporal sulci and gyri, in addition to the middle temporal gyrus. The temporal lobe is responsible for memory, language, and hearing.
The occipital lobe is the most posterior portion of the cerebrum. It rests on the tentorium cerebelli, a fold of dura mater that separates it from the cerebellum. The parieto-occipital sulcus also separates it from both the parietal and temporal lobes anteriorly. The occipital lobe includes the lunate and lateral occipital sulci, and is mainly responsible for vision.