Eye and Orbit Flashcards
accessory visceral structures
eyelids extraocular muscles nerves and vessels orbital fascia conjunctiva lacrimal apparatus
tarsi attachments
medial and lateral palprebral ligaments
tarsal gland secretion
lipids
bulbar fascia
posterior loose connective tissue going into the orbit
bulbar conjunctiva
anterior clear layer over the sclera
palprebral conjunctiva
clear layer lining eyelids
conjunctival sac
space bordered by bulbar and palpebral conjuctiva
conjunctivitis
inflammation of the conjunctiva
lacrimal glands produce
lacrimal fluid- lubrication
lacrimal fluid drains into
lacrimal canaliculi in inferomedial eye
lacrimal canaliculi drain into
lacrimal sac- superior dilation of nasolacrimal duct
lacrimal sac drains into
nasolacrimal duct which leads into nose
lacrimal gland location
fossa for lacrimal gland in superiolateral orbit
nasolacrimal duct drains into
inferior nasal meatus
anterior segment
anterior to lens
anterior chamber
anterior to iris
posterior chamber
posterior to iris
posterior segment
posterior to lens
aqueous humor
in anterior segment
vitreous humor
in posterior segment
glaucoma
increased anterior segment pressure caused by increased aqueous humor possibly due to blocked scleral venous sinus
scleral venous sinus
drains aqueous humor of anterior segment
located in the irido-corneal angle
sphincter pupillae
closes pupil via parasympathetic
dilator pupillae
opens pupil via sympathetic
sclera
attachment sites for extraocular and intrinsic eye muscles
most of light refraction by
corena
ciliary muscle contracts to
do accomodation- focus on near things
makes lens more rounded
2 layers of retina
neural- photoreceptors
pigmented- absorbs excess light so none is reflected
blood supply to retina
central artery/vein of retina
optic disc
medial (nasal)
where optic nerve and blood vessels enter
macula
lateral to optic disc where light hits the retina
fovea
indention in macula with highest visual acuity
choroid
layer with blood vessels
papilledema
bulging of the optic disc due to swelling of central vein of retina from compression by CSF in meninges due to increased cranial pressure
branches of the ophthalmic artery supplying the eye and surrounding
central artery of retina posterior ciliary lacrimal--> anterior ciliary supraorbital ethmoid branches
order of things light goes through
vitreous humor ganglion cell axons retinal ganglion cells bipolar neurons photoreceptors pigmented layer sclera
major visual pathway
retinal ganglion axons–> lateral geniculate nucleus (LGN)–> occipital lobe
pupillary light reflex
pretectum (between thalamus and midbrain)
optic nerve damage
lost vision from that side
optic chiasm damage
temporal fields lost in both eyes
optic tract damage
loss of opposite side visual field in both eyes, nasal in same side, temporal in other side
optic chiasm or tract comopression
flashes where there are none
medial orbit boarders
lacrimal
ethmoid
sphenoid
lateral orbit boarders
greater wing of sphenoid
frontal process of zygomatic
superior orbit boarders
orbital part of frontal
lesser wing of sphenoid
inferior orbit boarders
orbital process of palatine
maxillary
zygomatic
optic canal is in the
lesser wing of the sphenoid bone
4 holes in the orbital cavity
superior orbital fissure
inferior orbital fissure
fossa for lacrimal sac
infraorbital groove
superior orbital fissure location
between lesser and greater wings of sphenoid
optic canal location
in the lesser wing of sphenoid
inferior orbital fissure location
between the greater wing of sphenoid and maxillary bone
infraorbital groove location
anterior to inferior orbital fissure in the maxillary bone
contents of superior orbital fissure
V1, III, IV, VI
ophthalmic vein
fossa for lacrimal sac location
in the lacrimal bone (medial)
contents of infraorbital groove
infraorbital artery and nerve
periorbita
lining of bones of optic cavity and is continuous with the dura through the optic canal and the superior orbital fissure
function of superior rectus
adduct
elevate
medial rotate
function of medial rectus
adduct
function of inferior rectus
adduct
depress
lateral rotate
function of inferior oblique
abduct
elevate
lateral rotate
function lateral rectus
abduction
function superior oblique
abduct
depress
medial rotate
function levator palprebrae
elevate eye lid
what attaches at the common tendinous ring
rectus muscles
attachment of superior oblique
body of sphenoid, goes through trochlea to attach to the lateral eyeball
attachment of inferior oblique
floor of orbit
origin of oculomotor nerve
midbraine
visceral efferent- Edinger westfall nucleus
somatic efferent- occulomotor nucleus
path of oculomotor nerve
passes between the posterior cerebral and superior cerebellar arteries
crosses dura lateral to diaphragma stella
along lateral and superior cavernous sinus to enter the orbit through the superior orbital fissure
inferior branches of oculomotor nerve
infeiror oblique, medial rectus, inferior rectus
superior branches of oculomotor nerve
supeiror rectus, levator palprebrae
3 components forming ciliary nerve
GVE part of oculomotor
sympathetics
CN V1
parasympathetic role of CN III
pupillary light reflex
consensual pupillary reflex
lens accomodation
pupillary light reflex
constrict pupil in response to light
consensual pupillary reflex
shine light in one eye and the other constructs with it
lense accomodation
relaxation of ciliary body via contraction of ciliary muscles for near vision
path of parasympathetic branch of CN III
synapses on ciliary ganglion
postsynaptic fibers go to ciliary body and pupillary sphincter via ciliary nerves
CN IV innervates
superior oblique
origin trochlear nerve
midbrain- trochlear nucleus
longest intracranial nerve path
trochlear nerve
path of trochlear nerve
in subarachnoid space
passes over the superior cerebellar artery to cross dura at the tantrum cerebella and then along the lateral wall of the cavernous sinus to enter orbital at superior orbital fissure
origin of abducent nerve
pons- abducent nucleus
path of abducent nerve
comes out between the pons and medulla oblongata near the anterior inferior cerebellar artery
runs parallel to the basilar artery and goes through the dura near the cloves of the occipital bone
travels over the crest of petrous part of temporal and then inside the cavernous sinus with the internal carotid artery
longest intradural course nerve
abducent nerve
path of sympathetic nerves to eye
IML C8-T2–> sympathetic chain ganglion–> along internal carotid–> through ciliary ganglion–> short ciliary nerves to ciliary body and intraocular blood vessels and long ciliary nerve to dilator pupillae
pupil dilation
sympathetic
look up
CN III
SR
IO
look down
CN III and CN IV
IR
SO
lateral
III, IV, VI
SO
IO
LR
medial
III
MR
SR
IR
diagonal up and out
III VI
SR
LR
IO
diagonal up and in
III
SR
IO
MR
diagonal down and out
III IV VI
IR
SO
LR
diagonal down and in
III IV
IR
SO
MR
