Cerebrum

The cerebrum, which develops from the front portion of the forebrain, is the largest part of the mature brain. It consists of two large masses, called "cerebral hemispheres", which are almost mirror images of each other. They are connected by a deep bridge of nerve fibers called the "corpus callosum" and are separated by a layer called the "falx cerebri". The surface of the cerebrum is marked by numerous ridges or "convolutions", called "gyri", which are also separated by grooves. A shallow groove is called a "sulcus", and a very deep one is a "fissure". A "longitudinal" fissure separates the right and left hemispheres of the cerebrum, and a "transverse" fissure separates the cerebrum from the cerebellum. Various sulci divide each hemisphere into "lobes" (sometimes called "poles"). The lobes are named for the skull bones under which they rest and are: (1) the frontal lobe, (2) the parietal lobe, (3) the temporal lobe, (4) the occipital lobe, and (5) the insula. The cerebrum is concerned with higher brain functions, interpreting sensory impulses and initiating muscle movements. It stores information and uses it to process reasoning. It also functions in determining intelligence and personality.