Corpus callosum is the largest commissure of the brain. It connects the two cerebral hemispheres. It connects all pa of the cerebral coex of the two sides, except the lower and anterior pas of the temporal lobes which are connected by the anterior commissures. It is approximately 10 cm long, with an anterior end approximately 4 cm from the frontal lobes and posterior end approximately 6 cm from the occipital lobe. The superior surface of callosal trunk is covered by a thin layer of grey matter, the indusium griseum. Connection that link the same, or similar area on each side are termed homotopic connections. The corpus callosum also interconnects heterogeneous coical areas on the two sides (heterogenous connections). Fibres of corpus callosum The rostrum connects the orbital surfaces of the two frontal lobes. The forceps minor is made up fibres of genu that connects the two frontal lobes. The forceps major is made up of fibres of the splenium connecting the occipital lobes tapetum. Functional significance: The corpus callosum helps in co-ordinating activities of the two hemispheres.