Anterior Seg Anatomy Flashcards
what structure is a barrier for infections from the eyelids into the orbit & restricts fat from falling into the lid margin
orbital septum
what is the passageway for nasociliary nerve, CN3, CN6, CN2, & ophthalmic artery
common tendinous ring (annulus of Zinn)
what structure acts as a protective cover over EOM insertion into the sclera & separates the globe from orbital fat
Tenon’s capsule
what are the structures in the nasolacrimal drainage system
lacrimal puncta → canaliculi → lacrimal sac → nasolacrimal duct → valve of Hasner
what is the size of the canaliculi
10 mm ( 2mm vertical, 8mm horizontal)
what lies within the fossa formed by maxillary & lacrimal bones & is located anterior to the orbital septum
lacrimal sac
what is the size of the nasolacrimal duct
15mm long
what prevents backflow of nasal fluids into the nasolacrimal duct
valve of Hasner
what are the voluntary muscles of the orbit
EOMs & LPS
what are the involuntary muscles of the orbit
Muller’s muscle
what muscles are innervated by the superior branch of CN3
superior rectus, LPS
what muscles are innervated by the inferior branch of CN3
medial rectus, inferior rectus, inferior oblique, Muller’s
what are the three branches of the ophthalmic nerve (V1)
frontal, nasociliary, lacrimal
which branch of V1 innervates the cornea
nasociliary
what is the size of palpebral fissures
28-30mm wide, 9-10mm height
what structure is composed of collagen fibrils that surround the meibomian glands
tarsal plates
what provides rigidity to the eyelids
tarsal plates
what is a mucus membrane w/ non-keratinized squamous epithelium?
conjunctiva
what tissue maintains the shape of the globe
sclera
what are the layers of the cornea
epithelium → Bowman’s → stroma → Descemet’s → endothelium
which layers of the cornea cannot regenerate
Bowman’s & endothelium
what is the corneal stroma composed of
collagen fibrils, keratocytes, ECM
where are the stem cells of the cornea found
limbus
what is the thickest layer of the cornea?
stroma
what muscle originates at the common tendinous ring?
inferior rectus
what muscle is innervated by the sympathetic nervous system?
muller’s muscle
what ganglion is located inside the orbit?
ciliary
what is the average height of the palpebral fissure?
10 mm
what travels adjacent to maxillary sinus through the nasolacrimal canal & terminates at the inferior meatus
nasolacrimal duct
which branch of the nasociliary nerve innervates the conjunctiva, medial eyelids, lacrimal sac, caruncle, & side of nose
A) infratrochlear
B) long ciliary
C) short ciliary
infratrochlear
which branch of nasociliary nerve innervates the iris, corneal epithelium, anterior & middle corneal stroma & Muller’s
A) infratrochlear
B) long ciliary
C) short ciliary
long ciliary
which nasociliary branch innervates the ciliary body & iris sphincter?
A) infratrochlear
B) long ciliary
C) short ciliary
short ciliary
what height of the palpebral fissure would be considered eyelid retraction?
> 12 mm
the conjunctiva is composed of? which one contains goblet cells?
- epithelial layer → contains goblet cells
- stroma
which tissue contains superficial & deep vascular networks that are visible through the conjunctiva?
episclera
what layer is the attachment site for all EOMs?
sclera
what is the average central thickness of the cornea?
average peripheral thickness?
- central → 540-560 microns
- peripheral → 710 microns
what separates the anterior & posterior chambers?
iris
where are blood vessels located in in the iris?
iris stroma
