eye, orbit, and orbital Adnexa
nasocilary nerve branches and innervates
anterior and posterior ethomoidal nerves -- nasal cavity infratorchlear nerve (nasal dorsum and medial upper eyelid and eyeball)
aqueous chamber contains
anterior portion has iris = opens and closes eyelid = muscular diaphragm, iris seperates into anterior and posterior portion
chambers of globe
aqueous and virterous, seperated by lens
ptosis
both levator palprebrae superioris and superior tarsal muscle needed to keep eyes open, if you loose innervation to one = drooping of eyelid
V1 branches
lacrimal, frontal, nasociliary
lacrimal nerve innervates
lateral eyeball (sclera and cornea and upper lid) and lacrimal gland
eyelid elevators
levator palperae superioris superior tarsal muscle
ethmoidal foramina
on frontal bone ethmoidal nerves V1 ( nascociliary nerve) ethomidal arteris (opthalmic art)
blood supply to eye
ophthalmic and internal carotid arts
superior tarsal muscle
underneath levator palprebrae superioris and attached to tarsal plate (smooth muscle) innervated by sympathetic nerves lifts eyelid
bony orbit
7 bones, pear shaped roof: frontal bone floor: maxilla lateral wall: zygoma and greater wing of sphenoid medial wall: lacrimal, ethmoid (lamina papyracea, palatine
lateral rectus
ABduct (CN6)
medial rectus
ADduct
globe is ______ 23 degrees to direct the pupil in straight ahead position
ADducted
superior orbtial fissure
CN 3, 4 and 6 go through here and V1 and opthalmic veins
what's located in the wall of cavernous sinus and whats IN the sinus
CN 3, 4, V1, V2 are in WALL internal carotid and 6 are IN sinus
all sensory info from your cornea and sclear is from
V1 (opthamlic)
sensory nerves in orbit
V1, V2
accomdation
ability to look at infinity and then at 24 inches quickly 1) ADduction of eyeballs 2) miosis by sphincter pupillae (making pupils small) 3) relaztion of suspensory ligament of lens that results in lens rounding
tunic of globe
fibrous = sclera vascular = choroid neural layer = retina
obicularis occuli
closes the eyelid, inserts medially and laterally inervated by facial nerve (7)
basic tears
come from minor tarsal galnds, under the conjucvtiva used under normal conditions, under control of pterygopalantine ganglgion
ciliary muscles
contractoin of parasympathetic III = relaxation of suspensory ligs , lens rounding, near vision involved in accomadation
superior oblique
depress and ABduct (intorsion = med rotation) runs around the trochlea, fibers run posterior to insert on eyeball, inserts in the posterolateral aspect of gloe
inferior rectus
depresses and ADduction
iris contains what smooth muscles
dilar pupillae (sympath) constrictor pupillae (parasym)
inferior oblique
elevate and ABduct (extorision = lat rotation)
mvmts of eye
elevate, depress (up and down) ABduct (lateral) and ADduct (medial) intorsion (medial rotate) and extorsin (lateral rotate) used for focusing
superior rectus
elevates and ADduction occulomotor CN 3
ciliary body
extension of choroid makes and secfetes aqueous humor and drains them controls shape of lens via ciliary muscle
what occupies most of the orbital space?
fat, globe only 20%
lacrimal glands
function under stimulation (emotion or dirt), under control of pterygopalantine ganglgion
macula (fovea centralis)
geometric center of eye, where keen vision is generated
lacrimal gland innervation
greater petrosal branch (7) = preganglionic parasym pteygopaantine ganglgion = synapse then, zygomatic branch of V2 = postgang then to lacrimal gland
optic canal
in lesses wing wphenoid CN 2 comes out here and opthalmic arteries
V2 branches and innervations
infraorbital: skin lower eyelid, alveolar to teeth, upper lip and face zygomatic: skin cheek
inferior orbital fissure
infrorbital nerve (V2) zygomatic nerve (V2) alveolar nerves (V2) infraoritbal vein and art
cornea
modified epithelium convers anterior 1/6 of eye = refractive
levatator palprebrae superioris
most superior muscle in orbit (skeletal muscle) innervated by occulomotor CN III inserts into skin of eyelid lifts eyelid
CN 3 innervation of occulomotor muscles
nerve splits when it gets to rami, supeior ramus innervates the levator palpebrae and superior rectus, while inferior rectus goes to medial and inferior rectus and infrerior oblique
optic disk
neurovascular entrance to eyeball point of exit for ganglion cell axons leaving the eye. Because there are no rods or cones overlying the optic disc, it corresponds to a small physiological blind spot in each eye.
oculomotor parasympathetics
pregang: oculootor gang/synapse: ciliary post gang: short ciliary nerves smooth muslce of eye = constrictor pupillae
glaucoma inceases ---
pressure of aqueous chamber
annulus of Zinn ( tendinous ring)
ring forms origin for 5 of 6 extra oculuar muslce, all except inferior oblique (on maxilla) AND levator palpebrae
eyelid structures
skin conjuctiva (specialized epithelium on external eyelid) grayline conjugated sac orbital septum tarsal plate
tenon's capsule (bulbar fascia)
socket where globe site continuous with extra-ocular muscle fascia helps move prosthetic eyes
all extra occulmotor muscles innervated by CN 3 except
superior oblique (SO4) lateral rectus (LR6)
tear drainage system
superior puncta inferior puncta canaliculi nasolacrimal canal
branches of frontal nerve and innervations
supratrochlear (medial forhead) and supraorbital (lateral forehead)