Cerebral hemisphere

There are two cerebral hemispheres in the brain known as the cerebrum. The cerebral hemispheres are separated by a deep cleft called the longitudinal cerebral fissure, which contains the falx cerebri. However, they are connected below in the middle by white matter commissural fibers called the corpus callosum.

Antero-posteriorly, each cerebral hemisphere extends from the frontal to the occipital bones in the skull, above the anterior and middle cranial fossae. However, at the back, the cerebral hemispheres (or cerebrum) sit above the tentorium cerebelli.

The outer layer of each cerebral hemisphere is made up of gray matter called the cerebral cortex. The cortex has many folds called gyri and grooves called sulci. Certain larger sulci, called the interlobar sulci, divide the cortex into lobes. The cerebral cortex covers the subcortical white matter below it and also contains subcortical gray matter nuclei including the basal nuclei.

The cavity within each cerebral hemisphere is called the lateral ventricle (link). The lateral ventricle communicates with the third ventricle through the interventricular foramen of Monroe.