|Bone: Chiasmatic groove|
|Sphenoid bone. Upper surface. (Sulcus chiasmaticus labeled at center)|
|Base of the skull. Upper surface. (Sphenoid bone is yellow; chiasmatic groove labeled at center left, fourth from the top of the labels near the yellow region.)|
|Latin||sulcus prechiasmaticus, sulcus chiasmaticus|
|Gray's||subject #35 147|
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.
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