Lab 21 Orbit Flashcards
Which side of the eyeball is the optic nerve found on?
Lateral side
What is a sheet of CT between the tarsal plate and the bony orbital margin?
The orbital septum
Prior to and at the optic nerve, the nasociliary nerve gives off what?
Long ciliary nerves
What nerve passes directly anterior toward the superior orbital margin and bifurcates at its midpoint?
A. Lacrimal
B. Frontal
C. Trochlear
B. Frontal
Bifurcates into the supratrochlear nerve (more medial) and the supraorbital nerve (more lateral)
What connects the ganglion to the posterior surface of the eyeball?
Short ciliary nerves
The tarsal plates are found deep to what?
The palpebral portion of the orbicularis oculi muscle
What 3 superficial nerves pass from near the apex of the orbit superior to the extraocular muscles?
Frontal nerve
Lacrimal nerve
Trochlear nerve
Radial muscle fibers that work slowly to open the pupil
Dilator papillae
What do all the rectus muscles have in COMMON?
Common attachment to the common tendinous ring
Part of the vascular middle layer (color of eye)
iris
Clear, fibrous outer layer (anterior 1/6 of ball, 20%)
Cornea
White, fibrous outer layer (posterior 5/6 of ball, 80%)
Sclera
Space between the iris and anterolateral part of lens
Posterior chamber
What passes through the common tendinous ring? (There are 6 things)
Optic nerve (II) Abducens nerve (VI) Nasociliary nerve Superior and inferior divisions of the oculomotor nerve Central artery of the retina
What is a connective tissue sheath that will block the view/access to all contends of the orbit? What can be seen through this?
Periorbita
The frontal nerve can be seen through it
Circular muscles of iris that work to quickly close the pupil
Sphincter papillae
Where the optic nerve and retinal vessels enter/leave
Optic disc
Opening in the middle of the iris
Pupil
What nerve is medial to frontal nerve and follows the superior surface of the superior oblique? What does it innervate? ;)
Trochlear nerve, innervates the superior oblique
What is the bulbar conjunctiva attached to?
The sclera
What nerve crosses at an angle from posterolateral to anteromedial and is superficial to the optic nerve?
What is it a branch of?
Nasociliary nerve is a branch of V1
Space between the cornea and the iris/pupil
Anterior chamber
Following the inferior oblique muscle posteriorly will lead to the _____ division of the _______ nerve.
A. Inferior, oculomotor
B. Superior, oculomotor
C. Inferior, optic
D. Superior, optic
A. Inferior division of the oculomotor nerve
Which muscle bends at an acute angle to attach to the posterolateral portion of the eyeball?
Action(s) in neutral gaze?
Action(s) when abducted?
Action(s) when adducted?
Superior oblique, goes through the trochlea
Neutral gaze- intortion, abduction, depression
Abducted- intort
Adducted- depression
What is located superolaterally?
A. Trochlea
B. Inferior oblique muscle
C. Lacrimal gland
C. Lacrimal gland
The trochlea is superomedially
The inferior oblique muscle is attached inferomedially found more anterior at its origin but pass more posterior to its insertion on the eyeball
What is found deep to the lacrimal nerve?
Hint: it has 2 heads
What passes through the 2 heads? Medial or lateral surface?
The lateral rectus
The abducens passes through the 2 heads on the medial surface near the apex of the orbit
Put these in order of superficial to deep:
Superior rectus
Frontal nerve
Levator palpebrae superioris
CN III
Superficial- frontal nerve, levator palpebrae superioris, superior rectus, CN III- deep
What is the ophthalmic artery a branch of? It crosses _______ to the optic nerve from a ______ position.
A. Inferior, medial
B. Superior, medial
C. Superior, lateral
D. Inferior, lateral
The internal carotid artery
C
What is a slit like opening between the eyelids? A. Palpebral fissure B. Lacrimal caruncle C. Lacrimal papilla D. Lacrimal puncta
A. Palpebral fissure
The lacrimal caruncle is a fleshy bump in the medial angle
The lacrimal papilla is a small bump on the medial end of the eyelid
The lacrimal punta is a small opening at the apex of the papilla (used for dilation)
What nerve follows the lateral wall of the orbit to the lacrimal gland?
Lacrimal nerve :)
Inner layer, likely detached in cadaver eye
Retina
Where the vitreous body once was
Virtuous chamber
What is found between the optic nerve and the lateral rectus muscle? Where is this usually found?
The ciliary ganglion
Closer to the apex than to the eyeball
What is a membrane that lines the surface of the eyeball (sclera)?
A. Conjunctival sac
B. Palpebral conjunctiva
C. Bulbar conjunctiva
C. Bulbar conjunctiva
The palpebral conjunctiva is the membrane that lines the inner surface of the eyelid
The conjunctival sac is a potential space between bulbar and palpebral conjunctivae
