Orbit and Eye: Anatomy Flashcards
medial orbital walls
parallel
lateral orbital walls
perpendicular
orbital axes
long axis through orbit
-45% to one another
optical axes
long axit through globe
-parallel to medial walls
bones of orbit
frontal, maxilla, sphenoid, lacrimal, ethmoid, palatine, zygomatic
apex of orbit
lesser wing of sphenoid around optic canal
base of orbit
orbital margin and orbital opening
-frontal, zygomatic, maxilla
margin thickened - protection
roof of orbit
frontal bone and some sphenoid
-fossa for lacrimal gland
floor of orbit
maxilla bone
zygomatic bone
palatine bone
medial wall of orbit
ethmoid bone
lacromal bone
maxilla bone
lacrimal fossa
laterla wall orbit
zygomatic
greater wing sphenoid
foramina of orbit
optic canal superior orbital fissure inferior orbital fissure anterior ethmoidal foramen posterior ethmoidal foramen nasolacrimal canal
superior orbital fissure
CN III, IV, V1, VI and superior opthalmic vein
orbital blow out fracture
to thin orbital floor
-can involve maxillary sinus
or medial
enophthalmos - movement of fat into spaces
orbital tumors
sphenoid/ethmoid sinuses, middle cranial, infratemporal fossa
-erode to orbit
can cause exophthalmos
periorbital fascia
lines bones of orbit
continuous with fascia of extraocular eye muscles
check ligaments
medial and lateral
attach to medial and lateral orbital walls
limit abduction and adduction**
prevent posterior retraction of eyeball by rectus muscles
fascial sheath of eyeball
tenons capsule
- external to sclera
- continuous with muscular fascia of extraocular eye muscles
orbital fat
cushion, lubricate, protect
starvation
enophthalmos
-sunken in eyes
loss of orbital fat
layers of eyelids
skin loose CT muscle tarsal plate - main structural layer, dense CT palpebral conjunctiva
orbicularis oculi
close eye (sphincter of eyelid)
CN VII
levator palpebrae superiorirs
open eye
CN III
orbital septum
where tarsal plates connect
horners syndrome
loss of sympathetic to head
-ptosis - drooping of upper eyelid
loss of levator palpebrae superiorirs
superior tarsal portion of LPS
attached to superior tarsal plate
-innervated sympathetically