In vertebrates, the longitudinal fissure separates the cerebrum into two parts. The fissure is sometimes also called 'longitudinal cerebral fissure', 'great longitudinal fissure' or 'interhemispheric longitudinal fissure'. The two parts are often called cerebral hemispheres. The cerebrum is the largest part of the human brain.
A bundle of nerve fibres called the corpus calllosum connects the left and right hemispheres. A tough membrane called falx cerebri covers the fissure.