Anatomy of the Posterior Orbit Openings and Bones

Vocabulary flashcards reviewing the anatomical structures, posterior openings, and cranial nerve pathways of the orbit, based on Chapter 11.

Optic foramen

A small hole in the sphenoid bone located posteriorly at the apex of the cone-shaped orbit that allows for the passage of the optic nerve (CN II).

Optic nerve (CN II)

A cranial nerve that is a continuation of the retina and passes through the optic foramen.

Superior orbital fissure

A cleft or opening between the greater and lesser wings of the sphenoid bone, located lateral to the optic foramen, that transmits four primary cranial nerves (CN III to CN VI).

Cranial nerves III to VI (CN III to CN VI)

Four primary cranial nerves that pass through the superior orbital fissure to control movement of the eye and eyelid.

Inferior orbital fissure

An opening located between the maxilla, zygomatic bone, and greater wing of the sphenoid that transmits the maxillary branch of CN V.

Maxillary branch of CN V

A nerve branch passing through the inferior orbital fissure that provides sensory innervation for the cheek, nose, upper lip, and teeth.

Sphenoid strut

The small root of bone separating the superior orbital fissure from the optic canal, constituting a portion of the lateral and inferior wall of the optic canal.

Optic canal

A small canal into which the optic foramen opens, whose lateral wall is partly formed by the sphenoid strut.

Seven bones of the orbit

The seven bones composing the orbit: the frontal bone (orbital plate), sphenoid bone, palatine bone, zygomatic bone, maxillary bone, ethmoid bone, and lacrimal bone.

Rhese method

A parieto-orbital oblique projection of the orbits used to radiographically demonstrate the optic foramen and canal, sphenoid strut, and orbital margins.