GUIDE
Head and Neck: Orbit and Contents
Bony Orbit
Cavity containing and protecting five sixths of eyeball, associated muscles, nerves, and vessels.
Opening is protected by a thin moveable fold: the eyelid.
Supports, protects and maximizes the functions of the eye
Pyramidal shape with apex directed posteriorly and base anteriorly
Boundaries
Roof
Orbital plate frontal bone
Lesser wing sphenoid
Fossa for lacrimal gland found in orbital part
Floor
Orbital plate of maxilla
Some contributions from zygomatic and palatine bones
Contains inferior orbital fissure from apex to orbital margin
Medial wall
Paper thin
Orbital plate of ethmoid bone
Some contributions from frontal, lacrimal, and sphenoid bones
Indented by lacrimal fossa for lacrimal sac
Lateral wall
Frontal process of zygomatic bone
Greater wing of sphenoid
Apex
Lesser wing of sphenoid
Contains optic canal medial to superior orbital fissure
Foramina of the orbital cavityForamen Location Structures Transmitted
Supraorbital groove Supraorbital margin Supraorbital nerve and blood vessels
Infraorbital groove and canal Orbital plate of maxilla (floor) Infraorbital nerve and blood vessels
Nasolacrimal canal Medial wall Nasolacrimal duct
Inferior orbital fissure Between greater wing sphenoid and maxilla Maxillary nerve
Zygomatic branch maxillary nerve
Ophthalmic vein
Sympathetic nerves
Superior orbital fissure Between greater and lesser wings sphenoid Lacrimal nerve
Frontal nerve
Trochlear nerve
Oculomotor nerve
Abducent nerve
Nasociliary nerve
Superior ophthalmic vein
Optic canal Lesser wing sphenoid Optic nerve
Ophthalmic artery
Zygomaticofacial foramen Lateral wall Zygomaticofacial nerve
Zygomaticotemporal foramen Lateral wall Zygomaticotemporal nerve
Anterior ethmoidal foramen Ethmoid bone Anterior ethmoidal nerve
Posterior ethmoidal foramen Ethmoid bone Posterior ethmoidal nerveEyelids and Lacrimal Apparatus