the orbit :) Flashcards
function of the orbit
support and protect the eye and associated structures
bones of the orbit
frotal ethmoid lacrimal maxilla zygomatic sphenoid palatine
what makes up the roof of the orbit
frontal bone
lesser wing of sphenoid
floor of orbit
maxilla
zygomatic
greater wing of sphenoid
lateral wall of orbit
zygomatic
greater wing of sphenoid
medial wall of orbit
maxilla
lacrimal
ethmoid
body of sphenoid
what goes through the optic canal
optic and ophthalmic nerve
where is the optic canal found
lesser wing of sphenoid
what runs through the inferior orbital fissure
zygomatic branch of V2
where is the superior orbital fissure
between greater and lesser wing of sphenoid
layers of the globe
schlera
choroid
retina
sclera
white tough fibrous coat of eye
avascular
collagen type I and III
choroid
vascular
cornea
barrier
protects inner structure of the eye
transparent outer layer
iris
controls light entering the eye
lens
refract light as it passes into the eye
vitreous
helps maintain round shape
what is the eyelid raised bu
levator palpebrae superioris
what results in ptosis (drooping of eyelid)
loss of innervation of CN III ocularmotor
chemical thing for innervation of musucles of eye
3(LR6SO4)
abducens
trochlear
oculomotor
what does the superior rectus do
up or
midline
medial retcus
midline
superior oblique
down and out
inferior oblique
up and out
inferior rectus
down or
midline
lateral rectus
lateral
where do nerves pass through reach the orbit and where is ti
cavernous sinus
above and lateral to sphenoid air sinuses
what is cavernous sinus enclosed in
dura mater
how do the venous sinuses communicate with superficial sructures
through emissary sinuses
what is infection of cavernous isnus
cavernous sinus thrombosis
results in decrease or loss of vision
chemises
paralysis of cranial nerves which course through sinus
what can a tumour in the cavernous sinus lead to
mechanical compression of nerves
soft tissue injury
oedema and haemorrhage
bone injuries
fractures of lateral wall orbital roof and optic foramen
impure blow out
object much larger than the dimeter of the orbital rim
- orbital rim is fracture and floor is blown out
pure blow out
object same lie or lightly bigger than orbital rim
- rim intact, medial wall or floor blows out
what can cause rupture of the globe
objects smaller than the diameter of orbital rim
peri orbital ecchymosis
black eye
swelling of lids
subjective haemorrhage
eyeball red
loss of vision
injury to optic nerve or cilia body
traumatic mydraiasis
dilated pupil
numbness over distribution of infraorbital nerve
altered sensation
tingling over cheeck
what are facial fractures called
le fort fracures
1st degree le fort fracture
horizontal through maxilla
2nd degree le fort fracture
fracture through maxilla, nasal bone and inferior medial wall of orbit
pyramidal
3rd degree le fort fracture
zygomatic, lateral and medial wall of nasal bone
posterior and lateral orbit wall (facial skeleton detached from cranium)
i.e. horzizonal through eyes
