The anterior end of the corpus callosum

Corpus callosum

The 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...

 is named the genu

Genu

Latin for "knee", genu is a term commonly encountered in studies of anatomy. It is used to refer to several anatomical structures, including :* conditions affecting the knees, such as genu valgum and genu varum...

, and is bent downward and backward in front of the septum pellucidum

Septum pellucidum

The septum pellucidum , and not to be confused with the medial septum, is a thin, triangular, vertical membrane separating the anterior horns of the left and right lateral ventricles of the brain...

; diminishing rapidly in thickness, it is prolonged backward under the name of the rostrum, and is connected below with the lamina terminalis

Lamina terminalis

The median portion of the wall of the fore-brain vesicle consists of a thin lamina, the lamina terminalis, which stretches from the interventricular foramen to the recess at the base of the optic stalk and contains the organum vasculosum of the lamina terminalis, which regulates the osmolarity of...

, which stretches from the interventricular foramen to the recess at the base of the optic stalk.

The anterior cerebral arteries are in contact with the under surface of the rostrum; they then arch over the front of the genu, and are carried backward above the body of the corpus callosum.