adnexa of the eye Flashcards
what are the layers that make up the eyelid
skin
musculofibrous - pharyngeal muscles, somite muscles, smooth muscle and connective tissue and glands
palpebral conjuctiva
what is the tarsal plate and what does it do
stiff plate of connective tissue that supports the free edge of each lid
what is the cause of the common stye
inflammation and infection of one of the sebaceous glands
what is the sensory nerve supply to the region around the eyes supplied by
trigeminal nerve - ophthalmic division to upper lid and maxillary to lower lid.
where is the third eyelid situated at rest
canthus of eye
what is the third eye lid
t shaped cartilage supporting fold of conjuctiva
what does the lacrimal gland of the third eye do
sweeps across cornea when eyeball retracted by retractor bulbi muscles and returns to original position by contraction of smooth muscle within it
what is the lacrimal gland of the third eyelid innervated by
sympathetic nerves which run through middle of ear
function of tarsal gland
40 small openings secreting waxy surface preventing tears from spilling out of eye
what muscles of the eyelids does the palpebral branch of auriculopalpebral (facial nerve, CNVII, SVE) supply
oribcularis oculi
superciliaris
retracter anguli occuli
function of oribcularis oculi
eye lid closing muscle which sweeps tears across front of eye to keep clean and moist
function of superciliaris
lifts upper eyelid and eyebrow
function of Retractor anguli occuli
draws lateral angle posteriorly
what muscles of the eyelids does the occulomotor (CNIII, SE) supply
levetor palpebra superioris
function of levetor palpebra superioris
lifts upper eyelid
what does the sympathetic AE from cranial ganglion supply
smooth muscles of the upper and lower lids
components of the lacrimal apparatus
lacrimal duct
small associated glands
gland of third eyelid
lacrimal gland
what is the lacrimal gland and what does it do
flat lobulated gland secreting serous and mucous fluid to moisten the eye and supply the cornea with some nutrients
innervation of lacrimal gland
AE from facial nerve running via pterygopalatine ganglion onto the ophthalmic division of the trigeminal nerve
what happens in nasolacrimal duct
tears drain from lacrimal lake to lacrimal sac into lacrimal duct then into nasal cavity.
runs at first through wall of maxilla and then on internal surface covered by mucosa which opens dorsolateral wall of nostril
what is the periorbital fascia
cone shaped fibrous tunic surrounding eye and extraocular muscles
what are the 3 layers that make up the periorbital fascia
periorbita - most superficial
superficial muscular fascia - middle layer
deep muscular fascia - deep layer
what are the 7 extraocular muscles
4 rectus - dorsal ventral medial and lateral
2 oblique - dorsal and ventral
1 retractor - retractor bulbi
where does the rectus muscles insert
rostral to equator
