Functional Neuroanatomy Of The Brain Second Part - The cerebrum is the largest part of the human brain, and is divided into nearly symmetrical left and right hemispheres by a deep groove, the longitudinal fissure. The outer part of the cerebrum is the cerebral cortex, made up of grey matter arranged in layers. It is 2 to 4 millimetres (0.079 to 0.157 in) thick, and deeply folded to give a convoluted appearance.. This course is an introduction to the structures and functions of the Nervous System. Course content includes basic terms related to anatomical position, direction, body region, and body plane..