Orbit Flashcards
Which bones contribute to the orbit?
Frontal Zygomatic Maxilla Lacrimal Ethmoid Sphenoid Palatine
Where is the common tendinous ring located?
Surrounds the optic canal and a portion of superior orbital fissure
Which muscles control movement of the eyeball?
Superior rectus Inferior rectus Medial rectus Lateral rectus Superior oblique Inferior oblique
Which muscle is responsible for elevating the superior eyelid?
Levator palpebrae superioris
Which cranial nerves pass through the common tendinous ring?
Oculomotor nerve
Abducent nerve
Which cranial nerve bypasses the common tendinous ring?
Trochlear nerve
Where do the rectus muscles originate?
Common tendinous ring
Where do the rectus muscles insert?
Sclera - anterior to equator of the eyeball
Where does superior oblique originate?
Body of sphenoid bone
Where does superior oblique insert?
Sclera - posterior to equator of the eyeball
What structure redirects superior oblique? Where does it attach?
Trochlea/tendinous pulley
Frontal bone
Redirects SO backwards to its insertion
Where does inferior oblique originate?
Orbital surface of maxilla (anterior aspect of orbit)
Where does inferior oblique insert?
Sclera - posterior to equator of the eyeball
Where does levator palpebrae superioris originate?
Lesser wing of sphenoid bone
Where does levator palpebrae superioris insert?
Superior eyelid
Where does levator palpebrae superioris lie in relation to superior rectus?
Superior
Which muscles are innervated by CN III?
Superior rectus Medial rectus Inferior rectus Inferior oblique Levator palpebrae superioris
Where does the optic nerve exit the cranial cavity?
Optic nerve
Which nerves pass through the superior orbital fissure?
Oculomotor nerve
Trochlear nerve
Abducent nerve
What does the infundibulum/pituitary stalk pass through?
Diaphragma sellae
Which cranial nerves pass through the cavernous sinus?
Oculomotor nerve
Trochlear nerve
Abducent nerve
Where do the cranial nerves III, IV, and V lie in the cavernous sinus?
Close to lateral wall
Where does the abducent nerve lie in the cavernous sinus?
inferior to the internal carotid artery
How can CN VI be damaged in the cavernous sinus?
Intra-cavernous aneurysm of the internal carotid artery
