Eye and Orbit Flashcards
what bones make up the margin of the bony orbit?
frontal, maxilla, zygomatic
what bones are in the medial wall of the orbit?
lacrimal, ethmoid, lesser wing of the sphenoid, maxilla
what bones make up the superior walll (roof) of the orbit?
frontal
what bones make up the lateral wall of the orbit?
zygomatic
what bones make up the floor of the orbit?
PALATINE, zyomatic, maxilla
what travels through the optic canal?
optic canal, superior orbital fissure , inferior orbital fissure, anterior and posterior ethmoidal foramina, lacrimal canal, infraorbital groove
what travels through the superior orbital fissure?
with CN II, ophthalmic artery
what travels through the inferior orbital fissure?
ophthalmic, CN III, IV, and superior ophthalmic vein
what travels through the anterior and posterior ethmoidal foramina?
anterior and posterior ethmoid nerves and artery (from nasociliary on V1) to the sphenoid and ethmoid sinuses in the nasal cavity
what travels through the lacrimal canal?
lacrimal duct (connecting the orbit and nasal cavity)
what travels through the infraorbital groove?
passage of infraorbital nerve (v2) and artery from orbit to suborbit aread of face.
what are the medial/ lateral attachments of the orbicularis oculi palpebrae muscles?
medial and lateral palpebral ligaments; the medial palpebral ligament is exposed, and the lateral palpebral ligament is behind the orbicularis oculi palpebrae muscle
what is the function of the tarsal plates of the orbit?
collagenous plates that maintain the shape of the eyelids
what is the orbital septum?
a thin collagenous sheath that holds up the tarsal plates
what holds the tarsal plates in position?
the palpebral ligament; attaches to the maxilla (medially) and zygomatic (laterally)
what is the palpebral fissure?
the opening made by the upper and lower eyelids
what is unique about the superior tarsus compared to the inferior one?
the superior one is directly attached to the levator palpebrae suprioris muscle
what are the attachments of teh orbicularis oculi muscle?
palpebral part: attached to the tarsal plate
orbital: attached to the orbital septum and rim of the bony orbit
what nerve innervates the orbicularis oculi muscle?
Facial (VII).. temporal branch to upper eyelid, zygomatic to lower eyelid
what muscle is responsible for elevation of the upper eyelid?
levator palpebrae superioris (III) + superior tarsal muscle (postganglionic SYMPATHETIC)
what nerve innervates the levator palpebrae superioris?
occulomtor (III): superior branch
what does the superior tarsal muscle do? what it is innervated by?
assists the LPS to elevate the upper eyelid; has postganglionic sympathetics
what is conjunctiva? what does it come from? what are its divisions (where is each division located)?
= a thin, moist mucous layer of epithelium that comes from skin covering the external portion of the lids transitioning
Divisions: palpebral = attached to lids
bulbar = attached to the eye bulb
what are the superior and inferior conjunctival fornices developed from?
the transition of palpebral to bulbar conjunctiva creating a pocket under the upper and lower lids
where does the bulbar conjunctiva attach to the eye bulb?
cornea-sclera junction
what types of glands are associated with the eye?
sweat, lacrimal, Tarsal/Meibomian
How are sweat glands associated with the eye?
in the lashes and skin
what are tarsal/meibomian glands?
modified sebaceous glands that are embedded in the superior and inferior tarsal plates
what do meibomian glands appear as in the eye?
striations in the palpebral conjunctiva in each lid
what is the function of meibomian glands?
produce surfactant; a protein which spreads our water (doesn’t allow it to aggregate) so as to keep the cornea/eye moist so it doesn’t dry out; works with serous glands
where is the lacrimal gland located?
just below the SUPERIOR orbital rim, along its lateral margin
what divides the lacrimal gland?
tendon of LPS
where do the lacrimal ducts empty out into?
the lateral portion of the superior conjunctival fornix
how does the lacrimal gland receive innervation?
preganglionic axons travel down the greater petrosal nerve (VII) and join the deep petrosal nerve (T1) as the nerve to pterygoid, travels through the pterygoid canal, and then synapses on the pterygopalatine ganglion; then the postganglionic axons travel with the zygomatic nerve (V2) through the zygomaticotemporal branch to the lacrimal nerve (V1) to stimulate aqueous tear formation to keep the conjunctiva and cornea hydrated and clear from debris
what is the function of the lacrimal apparatus?
aspirating off tears from the surface of the eye and depositing them into the nasal cavity via nasolacrimal duct. It includes the nasolacrimal duct and lacrimal sac
where is the lacrimal sac located?
in the lacrimal fossa