Bony Orbit

Question 1

what are the 6 bones that make up the bony orbit?

Answer 1

frontal (superiorly)
zygomatic (laterally)
maxillary (inferomedial)
sphenoid, ethmoid and lacrimal internally

Question 2

which three bones of the bony orbit have orbital plates?

Answer 2

frontal
ethmoid
maxillary

Question 3

what are orbital plates?

Answer 3

areas of smoother/flatter bone that is thin walled and more likely to fracture

Question 4

describe how a blow-out fracture occurs?

Answer 4

pressure can be transferred through the thick bones during injury causing the orbital plates to fracture

Question 5

describe a trap-door fracture

Answer 5

contents of the orbit can herniate through a blow-out fracture e.g. fat, muscle, nerves

Question 6

where is the optic canal located in the bony orbit?

Answer 6

posteromedial

Question 7

what does the optic canal allow passage of in the bony orbit?

Answer 7

optic nerve

ophthalmic artery

Question 8

where is the superior orbital fissure located?

Answer 8

sphenoid bone

Question 9

what does the superior orbital fissure allow passage of into the bony orbit?

Answer 9

CNIII
CNIX
CNXI

Question 10

what does the supraorbital notch/foramen allow passage of?

Answer 10

supraorbital neurovascular bundle and supraorbital nerve (branch of CNV1)

Question 11

what does the infraorbital foramen allow passage of?

Answer 11

infraorbital branch (CNV2) and infraorbital vascular bundle

Question 12

what does the superior margin of the bony orbit do to protect the eye?

Answer 12

superior margin overhangs the inferior margin