According to About.com Biology, the corpus callosum connects the brain's two hemispheres. Innerbody.com reports that the corpus callosum is a broad arch that is divided into a curved front end called the genu and a backward-pointing portion called the rostrum, which tapers downward to connect with the lamina terminalis.
The corpus callosum is located beneath the cerebrum. Patricia Anne Kinser of Haverford College describes that this part of the brain engages in higher functioning, such as conscious thought and action. The divide between the hemispheres begins with the cerebrum. The two halves of the cerebrum have slight specializations, with the right side focusing on creativity and the left side focusing on logic. The corpus callosum, located underneath these two hemispheres, allows them to communicate between one another.
The corpus callosum also has some specializations itself. For example, in addition to relaying messages from one side of the brain to the other, Biology.About.com notes that the corpus callosum also is involved in controlling eye movement. Functions also include maintaining the balance between focused attention and arousal and in tactile localization.
The University of Washington adds that the cerebral hemispheres underneath the corpus callosum are connected via a smaller bridge of tissue called the anterior commissure. The corpus callosum itself contains between 200 and 250 million nerve fibers.