The Orbit Flashcards
the boundaries of the orbit are formed by how many bones?
7
what are the borders of the orbit?
* roof
* floor
* medial wall
* lateral wall
* apex
* base
- roof - frontal bone + lesser wing of sphenoid
- floor - maxilla, palatine, zygomatic
- medial wall - ehtmoid, maxilla, lacrimal, sphenoid
- lateral wall - zygomatic + greater wing of sphenoid
- apex - optic foramen
- base - orbital rim
?
what separates the orbit from the anterior cranial fossa
frontal bone
what separates the orbit from the maxillary sinus?
maxilla
what separates the orbit from the ethmoid sinus?
ethmoid
what does the orbit contain?
- eyeballs
- extra-occular muscles
- eyelids
- nerves
- blood vessels
- orbital fat
any space in the orbit that is not occupied is filled by what?
orbital fat
what is the role of orbital fat?
cushions the eye and stabilises the extraocular muscle
what is the arterial supply of the eye?
opthalmic artery
what is the venous drainage of the eye?
superior and inferior opthalmic veins
what are the 3 main pathways by which tructures can enter and leave the orbit?
- optic canal
- superior orbital fissure
- inferior orbital fissure
what travels through the optic canal?
optic nerve
opthalmic artery
what travels through the superior orbital fissure?
nerves:
* lacrimal
* frontal
* trochlear - CN IV
* oculomotor -CN III
* nasociliary
* abducens - CN VI
superior opthalmic vein
what travels through the inferior orbital fissure?
- zygomatic branch of maxillary nerve
- inferior ophthalmic vein
- sympathetic nerves
label the bones of the orbit
Label the major openings into the orbit
