orbit

Ace your homework & exams now with Quizwiz!

- to progressive neuropathy causes: - failure to drain aqueous humor - increased intraocular pressure (trauma/ damage/ blood)

glaucoma

oblique muscles

in anatomical movement of EOMs, abducting inactivates

rectus muscles

in anatomical movement of EOMs, adducting inactivates

extorsion

inferior ... EOMs

o: anterior orbital floor i: lateral globe, posterior to lateral rectus insertion a: elevation, extortion, abduction innervation: CN III

inferior oblique origin/ insertion/ action/ innervation

o: common tendiuous ring i: inferior globe a: depression, adduction, extorsion innervation: CN III

inferior rectus origin/ insertion/ action/ innervation

the retina (turns light signals to be integrated)

inner layer of eyeball

central retinal artery

inner retina blood supply

LR6 SO4 AO3 - lateral rectus CN VI - superior oblique CN IV - inferior oblique, medial rectus, superior rectus, and inferior rectus CN III

innervation for EOMs

accomodation - CN III (parasympathetic)

innervation of ciliary muscle and zonular fibers

medially

intorsion

- colored part of eye - Sphincter Pupillae (CN 3 parasympathetic) - Dilator Pupillae (sympathetic from superior cervical ganglion) ("fans out" - big in "fight or flight" bc want lights of light to see)

iris

Parasympathetic innervation from CN VII (facial) = greater petrosal nerve branch

lacrimal apparatus innervation

O: common tendinous ring i: lateral eyeball a: abduction innervation: CN VI

lateral rectus origin/ insertion/ action/ innervation

AVASCULAR no innervation refracts light

lens

elastic = unable to accomodate (lens is more flat) PRESBYOPIA

lens becomes less... with age = ?

o: common tendinous ring i: medial globe a: adduction innervation: CN III

medial rectus origin/ insertion/ action/ innervation

CN VII

motor innervation for closing eyelids

sclera

muscle attachment for EOMs

Choroid/Ciliary Body/Iris

muscular middle layer of eyeball

- Effects most ocular muscles (Levator Palpebrae Superioris & Sphincter Pupillae_ - What you'll see: a) Superior eyelid droop b) dilated/nonreactive pupil (unopposed dilator pupillae/sympathetic) c) Pupil will be down & out - bc trochlear/superior oblique is still intact pulling the eye laterally & down --> III, IV, and VI move eye (III is not intact - IV moves out, VI moves down and out --> that is way eye will move)

oculomotor (CN III) Palsy

levator palpebrae superioris (CN III) and Muller's (superior tarsal) (sympathetic)

opening the eyelid

choroid

outer retinal blood supply

contracts/ dilates

pupil

- CN 2 = afferent - CN 3 = efferent - Often 1st sign of oculomotor nerve compression is ipsilateral slowness of pupillary light response

pupillary light reflex afferent/ efferent/ clinical correlation

- visual retina - nonvisual retina - optic disc - macula and fovea

retina contains

- white part of eyeball - extension of dura mater/ optic sheath functions: - Provides site of attachment for extraocular muscles - Helps shape eyeball

sclera anatomy and function

CN V1 and V2

sensory innervation of orbit

macula and fovea highest amount of cones

sharpest vision

supraorbital (V1?) frontal (V1) CN IV

superficial n suppy to orbit

O: body of sphenoid bone I: tendon passes through trochlea attaching to eyeball lateral to superior rectus Act: depresses, intorsion, adduction Innervation: CN IV

superior oblique origin/ insertion/ action/ innervation

o: common tendinous ring i: superior globe a: elevation, adduction, intorsion innervation: CN III

superior rectus origin/ insertion/ action/ innervation

intorsion

superior... EOMs

- part of eyelid - secretes lipids -- lubrication of the eye - if overactive = eye boogies

tarsal gland

-Acellular viscous gel - 99% water - Fills space between lens & retina (in vitreous chamber of eye) - Helps maintain spherical shape of eyeball

vitreous humor

- separation of inner neural and outer pigmented layers cause: -Build up of pressure or fluids behind the retina & it pushes it off - Build up can be caused by too much produced or a blockage

what is detached retina and cause

optic disc where optic nerves leave

"blind spot"

"out"

... oblique EOMs

"in" (except for medial and lateral rectus)

... rectus EOMs

- brainstem disease/ head injury - diplopia (double vision) - muscles paralysis limits eye movement

EOM and orbital nerve palsies may be from/ result in:

-ptosis and pupil constriction sympathetic NS issue!!!!!!

Horner's syndrome

- Lateral rectus muscle is paralyzed/CANNOT ABDUCT (moves out) - Pupil deviates medially bc unopposed medial rectus muscle (moves in) --> lat rectus is unable to move eye laterally so eye pulled in medially

abducens (CN VI) nerve palsy

curvature of lens is changed to allow for focusing of objects as they approach the eye

accomodation

- Produced by: Ciliary Processes - Drains: Canal of Schlemm into Scleral Venous Plexus - Function: Nourishes cornea & lens

aqueous humor produced by/ drains/ function

-Instant & total blindness that is irreversible (AION) - Unilateral - Seen in older individuals

blockage of central retinal a

- Thrombophlebitis of cavernous sinus - Slow, painless loss of vision - May be reversible

blockage of central retinal v

Frontal Lacrimal Ethmoid Maxilla Zygomatic Sphenoid Palatine

bones of the orbit

- Partial or complete opacity of the lens - Develops from clustering of proteins in lens - Progressive neuropathy - Cause: failure to drain aqueous humor, resulting in increased intraocular pressure

cataracts

Anterior - between cornea & iris Posterior - between iris & lens Vitreous - big boy space behind lens

chambers of the eye

-"red eye" (light bounces off and refracts back) -supplies blood to outer layers of retina - branch of ophthalmic artery

choroid

- Connects choroid with circumference of iris - muscular and vascular functions - attaches to lens via Zonular Fibers - ciliary processes secrete aqueous humor

ciliary body - connects - functions - attaches - processes

zonular fibers relax, lens is spherical

ciliary muscles contracts: zonular fibers and lens...

zonular fibers tense, lens is flat

ciliary muscles relax: zonular fibers and lens...

rounded

close/ near vision = ? lens

orbicularis oris - palpebral part (inferior- gently closes eye) - orbital part (superior- squinting tightly

closing the eyelid

covers sclera and provides nutrients contains: - lateral angle - bulbar conjunctiva (covering schlera) - medial angle - palpebral conjunctiva (covering eyelid)

conjunctiva functions and contains

aids in light refraction innervated by CN 1 AVASCULAR (takes a long time to heal- how cornea is clear)

cornea: function/ inneervation

- use on coma pts - Touch cornea w cotton wisp - Normal Response = blink - Absence of blink may indicate CN V1 (sensation of cornea) or CN 7 lesion (ability to close eye/blink)

corneal reflex

ptosis (the eye is slightly open/ not all the way closed because Muller's muscle is still active)

damage to CN III (eyelids)

CN II CN III CN IV CN V1 (trigeminal) CN VI nasociliary frontal lacrimal

deep n supply to orbit

dim = dilated bright = constricted

dim light = ? pupil bright light = ? pupil

laterally

extorsion

flatter

far/ distant vision = ? lens

sclera and cornea (invisible, aid in light refraction)

fibrous outer layer of eye


Related study sets

XCEL Chapter 12 Idaho Laws and Rules

View Set

Microeconomics Exam 2 9,10, & 12 Study Guide

View Set

FNP Board Review: Pediatrics: Immunizations

View Set

Evolve Adaptive Quiz - Delegation

View Set

CHAPTER TWELVE: FL STATUTES, RULES, AND REGULATION PERTINENT TO LIFE INSURANCE

View Set