Splenium

The corpus callosum (Latin for 'tough body'), also callosal commissure, is a wide, thick nerve tract consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals. It spans part of the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them. It is the largest white matter structure in the human brain, about ten centimetres in length and consisting of 200–300 million axonal projections.Corpus callosumCoronal T2 (grey scale inverted) MRI of the brain at the level of the caudate nuclei emphasizing corpus callosumCorpus callosum parts on MRIDTI Corpus callosumCorpus callosum with AnatomographySagittal post mortem section through the midline brain. The corpus callosum is the curved band of lighter tissue at the center of the brain above the hypothalamus. Its lighter texture is due to higher myelin content, resulting in faster neuronal impulse transmission The corpus callosum (Latin for 'tough body'), also callosal commissure, is a wide, thick nerve tract consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals. It spans part of the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them. It is the largest white matter structure in the human brain, about ten centimetres in length and consisting of 200–300 million axonal projections. A number of separate nerve tracts, classed as subregions of the corpus callosum, connect different parts of the hemispheres. The main ones are known as the genu, the rostrum, the trunk or body, and the splenium. The corpus callosum forms the floor of the longitudinal fissure that separates the two cerebral hemispheres. It also forms part of the roof of the lateral ventricles. The corpus callosum has four main parts; individual nerve tracts that connect different parts of the hemispheres. These are the rostrum, the genu, the trunk or body, and the splenium. A narrowed part between the trunk and the splenium is known as the isthmus. The front part of the corpus callosum, towards the frontal lobes is called the genu ('knee'). The genu curves downward and backward in front of the septum pellucidum, diminishing greatly in thickness. The lower much thinner part is the rostrum and is connected below with the lamina terminalis, which stretches from the interventricular foramina to the recess at the base of the optic stalk. The rostrum is named for its resemblance to a bird's beak. The end part of the corpus callosum, towards the cerebellum, is called the splenium. This is the thickest part, and overlaps the tela choroidea of the third ventricle and the midbrain, and ends in a thick, convex, free border. Splenium translates as bandage in Greek.