=====Chiasmatic groove=====
sulcus prechiasmaticus [TA] a furrow on the superior surface of the sphenoid bone, located just anterior to the [[tuberculum sellae]]; it lodges the [[optic chiasm]]. Called also chiasmatic s., s. chiasmatis, optic groove..

The superior surface of the body of the [[sphenoid bone]] is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove, prechiasmatic sulcus), above and behind which lies the optic chiasma of cranial nerve 2 (the [[optic nerve]]).

The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity.

{{chiasmatic_groove.jpg?500|}}