Orbit And Cavernous Sinus - 4/7 Neal Flashcards
Post-ganglionics from the SCG to the lacrimal gland travel through what nerves?
Deep petrosal joins greater petrosal to form the vidian nerve
Describe the effects of Oculomotor nerve palsy?
Down and out gaze
Dilated pupil
Eyelid must be manually elevated due to ptosis
What motions of the eye are not included in the cardinal signs of gaze?
Straight up/down
Complete ptosis of the eye may be due to a lesion in what muscle?
From what nerve and what type of fibers?
Levator palpebrae Superioris (LPS)
CN 3, GSE
What are the PS responses of the eye?
Pupillary constriction (sphincter pupillae m.) Thickening of the lens for near vision (ciliary m.)
Lesion to the lateral rectus muscle results in what?
superior oblique?
Inability to ABduct the affected eye
When ADducted cannot depress the affected eye
Oculomotor nerve palsy has what 3 clinical signs associated with it?
Down and out eye
Complete ptosis
Pupil dilation
Loss of consensual light reflex is due to the destruction/lesion of what?
Posterior commissure
An aortic or carotid aneurysm can cause what?
What else may cause this symptom?
Decrease in Sympathetic outflow to the dilator pupillae muscle -> therefore pupillary constriction
Pancoast tumor (mass effect)
Lesion to what muscle will cause partial ptosis?
Innervated by what?
These fibers originate where?
Tarsal muscle of Muller
POST-ganglion if Sympathetic fibers
T1
What is anhydrosis?
If anhydrosis is absent, what else can you look for as a clinical Sx?
Lack of sweating
Flushing of the face (dilation of facial blood vessels) to half of the face
What is an Argyll Robertson pupil?
Unreactive to light with
Normal accommodation
What kind of response is accommodation? For what?
What is its associated triad?
Cortically-mediated response for near vision
Convergence of gaze
Pupillary constriction
Thickening of lens
What is a Holmes-Adie Pupil?
Topically slow reacting pupil to light
Normal accommodation
Transient, usually due to infection
What is hyphema?
Damage to what vessel causes it?
Pooling of blood in the anterior chamber of the eye
Arterial circle of iris
Grade 1 hyphema?
3?
Less than 1/3 volume in ant. Chamber
greater than 1/2 volume in anterior chamber
Damage to what vessel causes subconjunctival hemorrhage?
Where is bleeding restricted to?
Deep pericorneal plexus
Subconjunctival tissue or bulbar fascia
Damage to the superficial pericorneal plexus causes what?
Conjunctivitis
What structures are involved in a Le Fort 1 fracture?
Where does the fracture line pass through?
Horizontal maxillary fracture, separates teeth from upper face
Alveolar ridge, lateral nose and inferior wall of maxillary sinus
iMAN
What kind of fracture is Le Fort 2?
Fracture passes through what?
Pyramidal w/teeth at the base and nasofrontal suture at its apex
Alveolar ridge, lateral walls of maxillary sinuses, inferior orbital rim and nasal bones
LMAIN
Le Fort 3 fracture involves what?
Passes through what structures?
Craniofacial disjunction
Nasofrontal suture, maxillo-frontal suture, orbital wall, zygomatic arch
ZMON
The Ophthalmic artery comes off of what?
What are its branches?
ICA
Supraorbital Posterior ethmoidal a. Anterior ethmoidal a. Lacrimal Short ciliary arteries
What veins drain into the cavernous sinus?
Superior and inferior ophthalmic veins
Occlusion of the central retinal artery may cause what?
Abrupt, painless presentation
Cherry red macula seen on exam
What nerve in the eye is vulnerable to ischemia secondary to orbital fracture?
Inracanalicular portion of the optic nerve
What are the branches off of V1?
Where does it exit the skull?
Nasociliary
Frontal (Supraorbital and supratrochlear)
Lacrimal
Superior orbital fissure
Where does the maxillary nerve exit the skull?
Foramen rotundum
Where does V3 exit the skull?
What does it supply?
Foramen ovale
Muscles of mastication
The corneal reflex afferent component is sensed by what nerve?
Efferent component?
V1 (Nasociliary nerve)
Zygomatic and Temporal branch of CN 7
IN by 5
OUT by 7
Blow-out fractures cause Herniation of orbital structures such as ____ into the maxillary sinus?
Periorbita
Inferior oblique
Inferior rectus
Orbital fat pad
All extraocular muscles are attached to the tendinous ring (annulus tendinius) except what?
Inferior oblique muscle
Increased intracranial pressure may compress what nerve?
Causes what?
Abducens nerve (CN 6)
Paralysis of lateral rectus m.
What is the main sensory (GSA) nerve to the eyeball?
Nasociliary nerve
What is the chief artery of the orbit?
Where does it branch from?
Opthalmic a.
ICA
The opthalmic artery gives rise to what arteries which supply the optic nerve?
Posterior ciliary a
Central retinal a
The central retinal artery provides what with a centrifugal vascular supply?
What does it not supply?
Anterior optic nerve
Posterior optic nerve
How does the central artery supply the 4 quadrants of the retina?
Through upper and lower temporal branches
Upper and lower nasal branches
What forms the superior ophthalmic vein?
Where does it drain?
What else drains here?
Supraorbital and angular veins
Cavernous sinus
Central vein of the retina
The afferent component of the direct light reflex is mediated by what?
Where does the information first synapse?
Then where?
Optic nerve
Superior colliculus
Pretectum
The efferent component of the direct light reflex is mediated by what?
What nucleus?
What ganglion?
PS CN 3
Edinger-Westphal
Ciliary ganglion
Preganglionic sympathetic neurons for pupillary dilation are located where?
ILCC at T1
What is the site called for focusing detailed vision?
Fovea centralis
What causes papilledema?
Result?
Increased intracranial pressure
Swelling/edema of the optic disc
Sympathetic innervation to the lacrimal gland originates where?
Where do Pre-ganglionics synapse?
Post-ganglionic?
Sympathetic trunk
SCG
Travel through SPG but do not synapse
Blow-out fractures cause Herniation of what into the maxillary sinus?
Inf oblique m.
Inf rectus m.
Orbital fat pad
Describe draining of tears from the eye starting from the surface:
Lacrimal canaliculi -> lacrimal sac -> nasolacrimal duct -> inferior meatus
Csdim
Diplopia due to internal strabismus is the result of what lesion?
Abducens nerve
External strabismus is from lesion to what?
Oculomotor nerve
When a patient presents with their head tilted away from an eye that is stuck up and in, what lesion exists?
Trochlear nerve
What does the lacrimal artery give off?
Recurrent meningeal a.
