Bones of the orbit
After working through this study unit you will be able to:
- Identify the individual bones that form the walls of the orbit.
- Recognize the main features of each bone and its relations.
The orbits are two bony cavities located in the upper half of the facial skeleton on either side of the root of the nose. They form sockets that hold and protect the eyeballs and their associated structures. These structures include the optic nerve, extraocular muscles, the lacrimal apparatus, fascia and neurovasculature that supply them, as well as orbital fat within which these structures are embedded.
The walls of each orbit are formed of seven bones which are the frontal, maxilla, zygomatic, sphenoid, palatine, lacrimal and ethmoid bones. The bony walls of the orbit contain several fissures and foramina, which allow for the passage of neurovascular structures. Additionally, the orbital bones contain crests, ridges and tubercles that serve as surfaces of attachment for orbital structures, as well as fossae for structures such as the lacrimal gland and the lacrimal sac.
This video will help you learn about the bones of the orbit.
Take a quiz
Consolidate your knowledge by testing yourself with our quiz on the bones and bony structures of the orbit:
Are you ready to challenge yourself further? Try out this customizable quiz about the structures of the skull. You can customize this yourself to your preference.
Browse our atlas gallery to further review the bones and bony structures of the orbit you have covered so far.
|Orbital bones||7 bones that form the walls of the orbital cavity:
maxilla, frontal, zygomatic, ethmoid, lacrimal, sphenoid and palatine
Mnemonic: Many Friendly Zebras Enjoy Lazy Summer Picnic
|Walls of the orbital cavity||
Roof (superior): Orbital surface of frontal bone, lesser wing of sphenoid bone
Medial: Orbital plate of ethmoid bone, frontal process of maxilla, lacrimal bone, lesser wing of sphenoid bone
Floor (inferior): Orbital surface of maxilla, orbital process of palatine bone, zygomatic bone
Lateral: Frontal process of zygomatic bone, greater wing of sphenoid bone
|Fissures and foramina||Supraorbital foramen, infraorbital groove, infraorbital foramen, anterior and posterior ethmoidal foramina, optic canal, superior orbital fissure, inferior orbital fissure|
|Function||Forms the orbital cavity, protects the eyeball and related visual structures|