Sheath of optic nerve, annular tendon, oculomotor foramen
The optic nerve and its sheath has been cut across close to the optic foramen. The annular tendon (8) is fused medially and superiorly with the sheath. It is separated from the sheath inferiorly and laterally to form the oculomotor foramen for the entry of the nasociliary branch of the ophthalmic nerve (17), the oculomotor nerve (11,17,23,24) and the abducens nerve (19) into the central part of the orbit from the superior orbital fissure. The opthalmic artery (18), in its passage through the optic canal an foramen, is embedded in the sheath of the optic nerve. The superior ophthalmic vein has been removed.
Frontal nerve
Upper pointer: Superior rectus muscle Lower pointer: Subarachnoid space
Levator palpebrae superioris muscle
Optic nerve (II)
Sheath of optic nerve
Trochlear nerve (IV)
Superior oblique muscle
Common annular tendon
Oculomotor foramen
Periorbita
Inferior branch of oculomotor nerve (III) (branch to medial rectus muscle)
Medial rectus muscle
Ethmoidal cells (mucosa abnormally thickened)
Greater wing of sphenoid (cut across)
Recurrent meningeal branch of lacrimal artery
Lacrimal nerve
Upper pointer: Superior branch of oculomotor nerve (III) Lower pointer: Nasociliary nerve
Ophthalmic artery
Abducens nerve (VI)
Ciliary ganglion
Lateral rectus muscle
Temporalis muscle
Inferior branch of oculomotor nerve (III) (branch to inferior oblique muscle)
Inferior branch of oculomotor nerve (III) (branch to Inferior rectus muscle)