Orbit Flashcards
What muscle raises the eyebrows?
occupitofrontalis, or corrugator and procerus too
What nerve and fiber type innervates the lacrimal gland?
Greater petrosal nerve, parasympathetics
Of the iris muscles, which is innervated by sympathetics, and what nerve and ganglion supply them?
dilator pupillae, supplied by postganglionic sympathetics that came from the short ciliary nerves after the superior cervical ganglion
What fiber types does the ciliary ganglion carry and what are their sources?
GSA nasociliary nerve of V1, parasympathetics from inferior branch of CN III, sympathetics from superior cervical ganglion (they follow the internal carotid plexus)
What nerve branches provide sensory fibers to the globe of the eye?
long ciliary nerves (off of the nasociliary), and short ciliary nerves
A patient presents with an eye with drooping eyelid, constricted pupil, and anhidrosis. What do you suspect?
Horner’s syndrome
What are the muscles that lift the eyelid, and what are their innervations?
levator palpebrae superioris (GSE) and the superior tarsal muscle (sympathetic)
What is the cause of Horner’s syndrome?
Disruption of sympathetics to the orbit; most commonly CNS traumatic accidents, MS, lung tumors, brachial plexus trauma
What artery does the ophthalmic artery arise from?
internal carotid artery
What is the main venous drainage path of the orbit?
ophthalmic vein –> superior orbital fissure –> cavernous sinus
Describe the functions of the oblique muscles of the eye
Intorsion and extorsion (primary), elevation (inferior), depression (superior), abduction (both)
Why do you see an eye that looks down and out, dilated in the pupil, and a drooped eyelid in third nerve palsy?
down (unopposed sup. oblique), and out (unopposed lateral rectus), dilated (no parasympathetics to sphincter pupillae), and ptosis (III innervates lev. sup. palpebrae)
What does the ciliary muscle of the eye do?
relaxes the suspensory ligament of the lens to allow it to thicken to accomodate
What structures run with the optic nerve with the optic sheath?
Central retinal artery and vein
