Sunday, May 31, 2009

Occipital Lobe

The occipital lobe is the most posterior portion of the cerebral cortex of the human brain, at the back of the head. It is the smallest of the four lobes of each cerebral hemisphere and is separated from the parietal lobe by calcarine fissure. The occipital lobe is defined as the part of the cerebral cortex that lies underneath the occipital bone.

The occipital lobe is the visual center of the brain as it contains the primary visual cortex. Each visual cortex receives sensory information from the outside half of the retina on the same side of the head and from the inside half of the retina on the other side of the head. The cuneus, also called the Brodmann's area 17, receives visual information from the contralateral superior retina representing the inferior visual field. The lingula receives information from the contralateral inferior retina representing the superior visual field. The retinal inputs pass through a "way station" in the lateral geniculate nucleus of the thalamus before projecting to the cortex.