The Orbit Anatomy Flashcards
what does the orbit do
encloses the eye ball and tis associated structures
what is the apex of the orbit pyramid
optic foramen
what is the base of the orbit pyramid
orbital margins
what 7 bones form the orbit
frontal maxilla zygomatic sphenoid ethmoid lacrimal palatine
what bone makes u the superior border of the orbital rim
frontal bone
what bone makes up the medial border of the orbital rim
maxilla
what bone makes up the inferior border of the orbital ring
maxilla and zygomatic bones
what bones make up the lateral border of the orbital ring
frontal and zygomatic bones
what bones make up the roof of the orbit
frontal bone
the lesser wing of the sphenoid bone
what bones make up the floor of the orbit
Maxilla
Palatine
Zygomatic
(the floor is thin and can be fractured)
what makes up the medial wall of the orbit
lacrimal
maxilla
ethmoid
sphenoid
(also thin and easily fractures)
what bones make up the lateral wall of the orbit
the greater wing of the sphenoid
zygomatic
what causes an orbital blow out fracture
direct trauma to the eye (inside the orbit) causes a major rise in pressure in the orbit
this causes the thin medial wall/floor to fracture and the contents of the eye extrudes the orbit
how can orbital blow out fractures cause anaesthesia or paraethesia on the face
by affecting the nerves passing through the infraorbital foramen to the skin
what is the contents of the orbital
extra-ocular muscles
Eye lids
Nerves
Blood vessels
what artery supplies the eye with blood
primarily the ophthalmic artery - branches off the internal carotid
what veins drain the eye
the ophthalmic veins which train into the cavernous sinus
what are all the ways into the orbit (for vessels/nerves)
Optic canal Superior orbital fissure Inferior orbital fissure Nasolacrimal duct Supraorbital foramen/notch Infraorbital foramen Infraorbital groove
what travels through the optic canal
optic nerve Ophthalmic artery (that then branches off after traveling through the foramen)
what travels through the superior orbital fissure
NERVES lacrimal nerve frontal nerve trochlear nerve superior and inferior oculomotor nerves nasociliary branches of ophthalmic nerve Abducens nerve
Superior ophthalmic vein
what travels through inferior orbital fissure
zygomatic branch of maxillary nerve (CNV2)
Maxillary nerve
Inferior ophthalmic vein
what passes through the nasolacrimal duct
drains tears into nasal cavity
what passes though the supraorbital foramen/notch
nerves into the forehead supplying skin of the face
what passes through the infraorbital foramen
nerves
small vascular vessels
what is the infraorbital groove
passes across the floor of the orbit connecting with the infraorbital foramen which then opens up to the face
