The
posterior horn of the lateral ventricle (also
occipital horn,
posterior cornu of the lateral ventricle,
postcornu of the lateral ventricle) passes into the
occipital lobeThe occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1...
, its direction being backward and lateralward, and then medialward.
Its roof is formed by the fibers of the
corpus callosumThe corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...
passing to the temporal and occipital lobes.
On its medial wall is a longitudinal eminence, the
calcar avis (hippocampus minor), which is an involution of the ventricular wall produced by the calcarine fissure.
Above this the forceps posterior of the
corpus callosumThe corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...
, sweeping around to enter the
occipital lobeThe occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1...
, causes another projection, termed the bulb of the posterior cornu.
The calcar avis and bulb of the posterior cornu are extremely variable in their degree of development; in some cases they are ill-defined, in others prominent.