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Cole 6/14/11 lecture 2.5 hrs
113
Anatomy
Undergraduate 4
06/06/2011

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Term
roof: frontal bone (some medial wall)
medial wall: ethmoid & lacrimal bone
lateral margin: zygomatic(& lower margin), greater wing of sphenoid
floor: maxillary
Definition
what bones form the orbit?
Term
lacrimal bone
Definition
in what bone is the nasolacrimal canal that caries tear from the eye to the nasal cavity?
Term
frontal bone
Definition
this bone forms the orbital aperature
Term
ethmoidal foramina (anterior-bigger and posterior-smaller or absent, sometimes multiple posterior)
Definition
name the foramina through the fronal bone into the orbit (or through the suture between the frontal and ethmoidal bones)
Term
where the optic nerve enters, the optic canal
Definition
where is the deepest part of the orbit?
Term
opthalmic artery and optic nerve
Definition
what goes through the optic canal?
Term
lesser wing of sphenoid
Definition
what bone is the optic canal in?
Term
superior orbital fissure
Definition
name the gap between the greater and lesser wings of the sphenoid
Term
maxillary
Definition
this bone holds teeth, forms the hard palate, and the floor of the orbit
Term
inferior orbital fissure
Definition
name the fissure between the maxilla and the greater wing of the sphenoid
Term
they are continuous: The upper one stops at the lateral/inferior bend at the optic canal
Definition
how are the orbital fissures separated?
Term
annulus tendineus
Definition
this structure surrounds the optic canal and the inferomedial end of the superior orbital fissure. it is the site of origin for nearly all the extrinsic eye muscles
Term
optic nerve, opthalmic artery
Definition
name the structures that pass THROUGH the annulus tendineus
Term
skeletal muscle
Definition
what type of muscle are the extrinsic eye muscles?
Term
levator palpibrae the muscle to the eyelid, that actively opens the eye
Definition
all extrinsic eye muscles insert on the sclera except 1, name it
Term
inferior oblique
Definition
name the 1 extrinsic eye muscle that does not originate on the annulus tendineus
Term
superior rectus
Definition
this muscle lies in the upper medial part of the orbit and goes through a tendenous sling
Term
origin: maxilla on medial side of orbit
insertion: laterally on the eye(deep to lateral rectus)
Definition
where does the inferior oblique originate and insert?
Term
3,4,5,6
Definition
list the nerves in the orbit
Term
occulomotor CN 3

BONUS: this nerve also does pupil size and lens shape(ciliary muscle)
Definition
provides somatic motor innervation to all extrinsic eye muscles except superior oblique & lateral rectus

BONUS: what else does this nerve do?
Term
trochlear nerve CN IV (this muscle belly loops through the trochlea)
Definition
what provides motor innervation to superior oblique?
Term
opthalmic nerve, V1, a branch of the trigeminal n.
Definition
this nerve provides somatic sensory to everything in the orbit
Term
V2 maxillary nerve, a branch of the trigeminal CN V
Definition
this branch of the trigeminal n passes through the floor of the orbit without innervating anything in the orbit
Term
abducens CN VI
Definition
provides somatic motor innervation to lateral rectus
Term
the superior orbital fissure
Definition
how do nerves enter the orbit (besides the optic n)
Term
V1: opthalmic nerve (trigeminal)
Definition
what nerve tells you your eyeball is dry or itchy?
Term
upper division to superior rectus & levator palpibre

lower division to medial rectus, inferior rectus, inferior oblique

ciliary ganglion hangs off the lower division
Definition
name the branches of the occulomotor nerve, how does it get to the muscles it innervates?
Term
abducens, occulomotor, naosciliary nerve
Definition
these nerves goes through the annulus tendineus and superior orbital fissure to innervate orbit muscles
Term
Trochlear CN 4 (crosses behind levator palpibrae)

frontal and lacrimal nerves(branches of the opthalmic) also
Definition
these nerves come through the superior orbital fissure ABOVE the annulus tendineus
Term
they come in with the trochlear nerve
Definition
list the branches of the opthalmic nerve that enter the orbit, and where they come in
Term
1)opthalmic nerve(V1)
2)nasociliary nerve is the most important branch of ophthalmic
3) along with long cilliary nerves
Definition
what nerve does somatic sensory to the eye?
Term
sensory
Definition
trigeminal ganglia is purely ____
Term
trigeminal -> (v1)opthalmic -> nasocilliary -> long cilliary -> eyeball

short ciliary branch off nasociliary and pass through the ciliary ganglia (for CN 3) -> eyeball
Definition
some nerves form a ring around the eye and provide somatic sensory innervation, name the nerves that they branch off of starting with the trigeminal nerve
Term
occulomotor CN 3, paraympathetics synapse in the ciliary ganglia (it contains post ganglionic parasympathetic cell bodies
Definition
what nerve provides parasympathetics to the eye? where do they synapse?
Term
short ciliary nerves have post ganglionic parasympathetics from ciliary ganglia, sympathetics from the internal carotid plexus (post ganglionic) and the somatic sensory from the V1
Definition
what mixed nerves contain occulomotor fibers, sympathetic fibers, and trigeminal nerve fibers to the eye?
Term
nasociliary sends branches through from trigeminal origins

sympathetics send branches through from the internal carotid plexus
Definition
name the 2 nerves that pass through the ciliary ganglia and do not synapse
Term
parasympathetics from CN 3 that synapse in ciliary ganglia

takes muscular effort to focus on close things especially (accomodation)
Definition
what innervates the ciliary muscle?
Term
parasympathetics from CN 3 occulomotor N
Definition
what innervates constrictor pupillae?
Term
sympathetics from internal carotid plexus
Definition
what innervates dilator pupillae?
Term
autonomics
Definition
what kind of innervation goes to intrinsic eye muscles?
Term
zonular fibers
Definition
ring of CT holding the lens
Term
ciliary muscle
Definition
this muscle attaches to zonular fibers and when the muscle is relaxed, the zonula fibers are taught so the lens is stretched thin
Term
since the ciliary muscle is like a sphincter around the zonular fibers, when it contracts, it makes the rim holding the zonula fibers a smaller diameter, zonular fibers are slackened, and the lens becomes rounded and thicker

like a belt tightening

close objects take muscular strength to focus, far objects rely on passive tautness of CT
Definition
when the ciliary muscle contracts, how does it affect the lens?
Term
pupil (in the iris)
Definition
which is more anterior? pupil or lens?
Term
constrictor pupilae
Definition
this muscle is a band that runs around the iris that tightens like a belt with fibers like a sphincter
Term
like spokes of a wheel, so when it constricts, it pulls the pupil open
Definition
what direction are the fibers of dilator pupilae?
Term
where there is no muscle activity (straight ahead)
Definition
what position is the eye in, in resting gaze?
Term
looking towards the midline (defined by the pupil) aka medial gaze
Definition
which direction is ADDUCTION of the eye?
Term
looking temporally (laterally)
Definition
ABDUCTION of the eye is looking which way?
Term
adducting or abducting
Definition
looking which directions use only 1 muscle?
Term
it is more medial in the orbit (which doesn't matter with the muscle direction/actions)
Definition
where is the optic canal in the orbit? centered? medial, or lateral?
Term
when you cross your eyes (use both medial rectus), or when you are accommodating
Definition
when do you have the same rectus muscles working in each eye?
Term
superior rectus, and inferior oblique
Definition
what muscles are used for elevation?
Term
up and inward
Definition
what direction does superior rectus pull the eye on its own?
Term
up and outward (pulls lateral part of eye down)
Definition
what direction does inferior oblique pull the eye on its own?
Term
down and inward
Definition
what direction does superior oblique pull the the eye on its own?
Term
down and outward
Definition
what direction does inferior rectus pull the eye on its own?
Term
have the patient abduct from the resting position (look laterally)
Definition
how do you test lateral rectus?
Term
have the patient look medially (adduct)
Definition
how do you test medial rectus?
Term
the oblique muscles
Definition
which muscle attach to the posterior half of the eye?
Term
medial (then down for superior, and up for inferior)
Definition
to test oblique muscles, which direction must you have the patient move their eye first?
Term
temporally (laterally) then up or down (superior look up, posterior look down)
Definition
to test the superior and inferior rectus muscles, which direction must you have the patient look first to test the eyes?
Term
the posterior superior, lateral surface of the eye (so it pulls from an anterior, superior, and medial position)
Definition
where on the eye does the superior oblique attach?
Term
the inferior, posterior, lateral surface of the eye (so it pulls from medial, anterior, and inferior)
Definition
where on the eye does the inferior oblique attach?
Term
on the frontal bone, medially
Definition
where is the trochlea?
Term
you get lateral strabismus because lateral rectus is unopposed

BUT you also get SLIGHT down and inward rotation because superior rectus is unopposed, SO

overall, lateral strabismus and slight downward tilt
Definition
if there is an occulomotor nerve lesion, what muscles are unaffected? what direction will the eye move?
Term
turn their head to the side that is normal and tilt their head to the affected side

this puts the other eye medial so it is in the natural corresponding medial location to re-align the eyes)
Definition
if there is an occulomotor nerve lesion, how can the patient prevent seeing blurry?
Term
you get medial strabismus, because medial rectus takes over

turn head to affected side to re-align the eyes (and prevent blurred vision)
Definition
if there is an abducens nerve lesion, what does the eye do? how would you align their eyes?
Term
blurred vision, especially when looking down, because inferior rectus takes over pulling the eye up and lateral (so one eyes is stuck up as the other looks down)

tilt head to affected side to prevent blurring
Definition
what happens to the eye when you have a trochlear nerve lesion? how would you prevent blurring?
Term
when looking down like at stairs, or reading a book
Definition
when is a trochlear nerve lesion most noticeable?
Term
look at the glare (the light reflex) on both pupils to see if they are in the same place
Definition
whats the easiest way to tell someone's eyes are aligned?
Term
the optic nerve has a pia mater, an arachnoid mater, and a dura mater
Definition
the eyes are an outgrowth of the brain, what does this mean in regards to the meninges?
Term
through the subarachnoid space around the optic nerve

the eye is also a CSF drainage route
Definition
how does meningitis reach the eye?
Term
the dura around the nerve fuses to the periosteum of the optic canal
Definition
what prevents the optic nerve from sliding back and forth?
Term
periorbita
Definition
name the periosteum lining the orbit
Term
no, it is in a giant ball of fat

(thats why people who have lost a lot of weight have sunken looking eyes)
Definition
does the eye contact bone?
Term
there is a periscleral fascial cleft, then a layer of Fascia bulbi

muscles pierce the fascia and bridge the cleft
Definition
what lines the eye from behind (outside the sclera)?
Term
to the smooth muscle of the upper eyelid, sweat glands, and vasculature (the V1 dermatome)
Definition
where else do sympathetics from the internal carotid plexus go besides the short ciliary nerves to the dilator pupilae?
Term
they come with the facial nerve through the inferior orbital fissure and form the lacrimal nerve to innervate the lacrimal gland
Definition
where do parasympathetic that travel through the orbit go that don't do intrinsic eye muscles?
Term
it is contained inside the epineurium(dura) of the nerve, but sits inferior to the nerve fibers
Definition
where is the opthalmic artery in relation to CN 2?
Term
ICA
Definition
what artery feeds the opthalmic artery?
Term
1) posterior ciliary arteries
2) central artery to the retina
3) lacrimal artery (and anterior ciliary)
4) supraorbital artery
5) posterior/anterior ethmoidal
6) splits to infratrochlear, and
7) supratrochlear
Definition
list the branches of the opthalmic artery
Term
lacrimal artery (branch of opthalmic)
Definition
this artery goes along the upper, lateral wall of the orbit to the lacrimal gland
Term
anterior ciliary artery
Definition
name the branch of the lacrimal artery that supplies the external eye tissue (the outer layers of sclera, not retina)
Term
posterior ciliary arteries (usually 2)
Definition
these arteries form a ring round the optic nerve to supply posterior sclera after traveling on either side of the optic nerve
Term
starts inferior to the optic nerve, comes lateral and superior, then goes medially (crossing over the top of the optic nerve)
Definition
describe the path of the opthalmic artery through the orbit
Term
supraorbital artery
Definition
supplies skin above the orbit, branches off the opthalmic artery once it is superior and medial to the optic nerve and travels OVER the eye
Term
suprtrochlear artery
Definition
this artery runs over the tendon of the superior oblique to supply skin on the midline around the eye
Term
infra trochlear nerve
Definition
this artery goes to skin...somehwere and travels below the trochlea to the bridge of the nose
Term
anterior and posterior ethmoidal arteries
Definition
these arteries go through the medial wall of the orbit through foramina that share their name
Term
central artery of the retina
Definition
this artery is essential to supplying the retina, branches off the opthalmic then tunnels into the core of the optic nerve to get into the eye
Term
1) supratrochlear(medial) and supraorbital(lateral) from the ICA
2) superficial temporal (from ECA)
3) posterior auricular (ECA)
4) occipital artery (ECA)
Definition
these arteries contribute to the blood supply of the scalp and anastamose, name the arteries and what major vessel they branch off
Term
no, it is where the dura stretches over a depression in the bone
Definition
is the cavernous sinus associated with a dural fold?
Term
ICA
cranial nerves 3,4,5,6
Definition
name the structures in the cavernous sinus
Term
the sinus starts where the ICA crosses the foramen lacerum and turns up

it then goes anterior and lateral to make a u turned sideways in a sagittal plane

it exits the cavernous sinus when it turns vertical and posterior
Definition
what directions does the ICA go while in the cavernous sinus?
Term
3,4,5,6
Definition
name the nerves in the cavernous sinus from superior to inferior
Term
lateral to the artery
Definition
where are the cranial nerves in relation to the ICA in the cavernous sinus?
Term
trochlear nerve CN 4
Definition
smallest cranial nerve
Term
VI (abducens), so its function is lost first
Definition
which nerve in the cavernous sinus is surrounded by blood on all sides and would be most affected by increased pressure in the cavernous sinus?
Term
CN 3 occulomotor
Definition
this nerve lies superior and lateral to the ICA in the cavernous sinus
Term
CN 6 abducens
Definition
this nerve is inferior and medial to CN 4 and 5 in the cavernous sinus
Term
face dura laterally, so they dont lose functions as fast as the abducens with increased pressure in the sinus
Definition
CN 3, 4, and V1 medially face the cavernous sinus, what do they face laterally? what does this mean?
Term
1) facial vein (drains medial eye and jawline) but connected to orbital veins which prefer to flow back to the sinus
2) opthalmic veins (sup and inf)
3)
Definition
what drains to the cavernous sinus?
Term
1) primarily drain straight down to infratemporal fossa (pterygoid plexus
2) superiorly to superior petrosal sinus
3) inferior to inf. petrosal sinus then internal jugular
Definition
what drains the cavernous sinus?
Term
no valves
Definition
if there is an increase in BP, why does blood flow in reverse in the cavernous sinus?
Term
a triangle formed by connecting the corners of the mouth to the bridge of the nose
Definition
where is the danger area of the face?
Term
facial vein, but these are connected to opthalmic veins in the orbit, so they can get into the cavernous sinus

therefore an infected pimple can spread infectious material back and get caught up in the fibers in the cavernous sinus
Definition
what drains the danger zone of the face?
Term
cavernous sinus thrombosis
Definition
what condition can result from to much infectious material clogging up the cavernous sinus by getting caught in the webby material in it?
Term
1) medial strabismus (abducens compression)
2) eventual paralysis of all extrinsic eye muscles (fixed eye-rest of nerves knocked out)
3) pupil fixation (compression of autonomics of the IC plexus)
4) edema of the eyelid and pulsating exopthalmos (lymph drains to opthalmic veins)
5) parasthesia of the V1 dermatome
6) Horner syndrome (compression of sympathetics)
Definition
describe the clinical signs of cavernous sinus thrombosis in order they would appear after the pressure increases
Term
the ICA
Definition
what artery causes pulsating exophthalmos in cavernous sinus thrombosis?
Term
a collection of symptoms that occurs when sympathetic innervation is disrupted to the head (in cavernous sinus thrombosis this is restricted to the V1 dermatome)
Definition
describe horner syndrome
Term
1) paralysis of dilator pupilae (constricted pupil)
2) ptosis - paralysis of smooth musc of upper eyelid
3) loss of sweating (anhydrosis)
4) flushing of skin (paralysis of smooth muscle that constricts cutaneous arterioles)
Definition
what are the symptoms of horner syndrome?
Term
1) ethmoiditis
2) periorbital edema
3) proptosis
4) meningitis
5) infection around the pterygoid muscles
6) diplacement of dura in the lateral wall
7 compresion of the ICA
Definition
what symptoms of cavernous sinus thrombosis can be seen with a CT of the head?
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