The chiasmatic groove (chiasmatic sulcus, optic groove, prechiasmatic sulcus) is a transverse groove upon the superior aspect of the

body of sphenoid bone The body of the sphenoid bone, more or less cubical in shape, is hollowed out in its interior to form two large cavities, the sphenoidal sinuses, which are separated from each other by a septum. Superior surface The superior surface of the body ...

within the

middle cranial fossa The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the pituitary gland. It is deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull ...

. It is bounded anteriorly by the sphenoidal limbus (a variably prominent ridge also representing the posterior boundary of the sphenoidal jugum), and posteriorly by the tuberculum sellae. The

opening Opening may refer to: Types of openings * Hole * A title sequence or opening credits * Grand opening of a business or other institution * Inauguration * Keynote * Opening sentence * Opening sequence * Opening statement, a beginning statemen ...

of each

optic canal The ''optic foramen'' is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid. The superior surface of the sphenoid bone is ...

is placed at either lateral end of the chiasmatic sulcus. The

optic chiasm In neuroanatomy, the optic chiasm, or optic chiasma (; , ), is the part of the brain where the optic nerves cross. It is located at the bottom of the brain immediately inferior to the hypothalamus. The optic chiasm is found in all vertebrates, ...

is situated superior and quite posterior to the chiasmatic groove (and not against the groove as the name suggests).

References

External links

* * (#7) Bones of the head and neck {{musculoskeletal-stub