Lecture 32 DA Flashcards
Where is the supraorbital margin?
The frontal bone directly under the eyebrow, forming a ridge.
What is the dint above the supraorbital margin called, and what passes here?
Supraorbital notch. Neurovascular vessels to the forehead pass here.
Where is the infraorbital margin? What forms it.
Directly inferior to the eyeball. Formed by zygomatic bone laterally and maxilla medially.
What is the superior roof of the orbit?
Orbital plate of the frontal bone.
What forms the posterior wall of the orbit?
Lesser wing of sphenoid laterally, and ethmoid bone medially.
What can be found on the medial wall of the orbit?
Ethmoid bone and lacrimal bone.
What is the structure of the ethmoid bone like?
Very thin, called papyrus region for this reason.
What forms the floor of the orbit?
Maxilla medially, zygoma laterally, and palatine superior to the two.
What can be found on the lateral wall of the orbit?
Zygomatic bone.
Why do some bones in the orbit break so easily?
They break to protect the eye so pressure doesn’t damage it.
What passes through the optic canal?
Optic nerve with the ophthalmic artery.
What nerves pass through the superior orbital fissure?
Ophthalmic division of the trigeminal nerve and extraocular muscle nerves.
What forms the superior orbital fissure?
Gap between lesser and greater wing of sphenoid.
Where is the inferior orbital fissure?
Inferior to the superior orbital fissure.
What are the three layers of the eye?
Outer coat
Cornea/sclera
Middle layer
Uvea
Inner coat
Retina
What is the purpose of the sclera?
Strength, is very tough and durable. Maintains shape, attachment for muscles and resists forces.
