What is Corpus callosum?

The great commissural plate of nerve fibers interconnecting the cortical hemispheres (with the exception of most of the temporal lobes, which are interconnected by the anterior commissure). Lying at the floor of the longitudinal fissure, and covered on each side by the cingulate gyrus, it is arched from behind forward and is thicker at each extremity (splenium [TA] and genu [TA]) but thinner in its long central portion (truncus [TA]); it curves back underneath itself at the genu to form the rostrum [TA] of the corpus callosum.