Eye Flashcards
7 bones that form the bony orbit
- Frontal
- Zygomatic
- Maxillary
- Sphenoid
- Lesser wing
- greater wing
- Ethmoid
- Lacrimal
- Palatine
Name the 3 aperatures of the posterior wall of the orbit: and what passes through them?
Optic canal • Optic nerve • Ophthalmic artery Superior orbital fissure • CNs III, IV, V1, VI • Superior ophthalmic v. Inferior orbital fissure • Infraorbital n. • Infraorbital a. & v
Name the 3 aperatures of the anteior wall of the orbit:
Bony rim of the orbit
Fossa for lacrimal sac & duct
Superior orbital foramen (or notch)
• Supraorbital n.
• Supraorbital a. & v
Name the 3 aperatures of the side walls of the orbit:
Ant. ethmoidal foramen • Ant. ethmoidal nerve • Ant. ethmoidal a. & v. Post. ethmoidal foramen • Post. ethmoidal nerve • Post. ethmoidal a. & v. Infraorbital Groove • Infraorbital nerve • Infraorbital a. & v
What are the parts of the eyelids? What is the space between the lids called?
Moveable skin flaps (palpebrae)
• Upper lid (palpebra superioris)
• Much more mobile than the lower lid (palpebra inferioris)
• Usually covers part of iris
• Palpebral fissure is the space between the lids
Explain location:
Medial & lateral palpebral commissures
Medial canthus & lateral canthus
Medial & lateral palpebral commissures - outside on skin near where the eye lids meet
Medial canthus & lateral canthus - on the inside edges of the eye lids where they meet
What makes up the deep part of the eyelids?
superior and inderior tarsal plates and medial and lateral palpebral ligaments
Describe the conjuntiva: N81
• Membranous sac (with aslit at the palpebral fissure)
• Transparent
• Bulbar part overlies sclera
• Palpebral part lines eyelids
• Bulbar conjunctiva stretches from the corneal
limbus to fornices
• Palpebral conjunctiva stretches from the fornices to the palpebral fissure
Describe the Lacrimal Gland & Apparatus N82
- Lacrimal gland
- Lacrimal lake with lacrimal caruncle
- Lacrimal papillae
- Lacrimal puncta
- Lacrimal canaliculi
- “Trail of tears”
- Lacrimal sac
- Nasolacrimal duct to nasal cavity
Orbicularis Oculi muscle attachments
• Origin from medial palpebral ligament (lacrimal bone & bony orbit)
• Inserts on skin & tarsal plates
• Functions to close the eyelids
Palpebral part – gentle closing of eyelids
(“blinking”)
Orbital part – tight closing of eyelids (“winking”)
• Innervated by CN VII (zygomatic & temporal branches)
Levator Palpebrae Superioris
Originates from the orbital roof and common tendinous ring
• Inserts into the superior tarsal plate 84N4
• Innervated by the superior division of CN III
• Functions to elevates upper lid under voluntary control
Superior Tarsal Muscle (of Mullër)
Superior Tarsal Muscle (of Mullër)
• Smooth muscle (involuntary)
• Originates off the levator palpebrae superioris m.
• Inserts on the superior tarsal plate
• Elevates tarsal plate
•Innervated by posynaptic sympathetics from carotid
plexus
•Contributes to the “wide-eyed”expression when the individual is excited
Muscles of eye innervated by CN III
- Medial rectus m.
- Superior rectus m.
- Inferior rectus m
- Inferior oblique
Muscles of eye innervated by abducens (VI)
lateral rectus
Muscles of the eye innervated by the trochlear n. (IV)
superior oblique
Which muscles insert on the Common tendinous ring (annulus of Zinn)
Gives origin to 4 “rectus”
extraocular muscles
and 1 “oblique”
extraocular muscle
Doesn’t do the inferior rectus muscles