Orbit and Extraocular Muscle Testing Pt. 2 Flashcards Preview

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Flashcards in Orbit and Extraocular Muscle Testing Pt. 2 Deck (39):

What are the 5 structures in the orbit that receive autonomic innervation?

1.) Dilator pupillae muscle
2.) Constrictor pupillae muscle
3.) Ciliary Muscle
4.) Levator palpebrae (smooth muscle part)
5.) Lacrimal gland


Of these 5, which two only get SYMPATHETIC innervation?

Dilator pupillae and levator palpebrae


Of these 5, which two receive only PARASYMPATHETIC innervation?

constrictor pupillae and ciliary


OF these 5, which is the only one to receive BOTH sympathetic and parasympathetic innervation

Lacrimal gland


The sympathetic innervation of the dilator pupillae and levator palpebrae is via postganglionic fibers whose cell bodies are in the

Superior cervical ganglion


The preganglionic sympathetic fibers arrise from



The parasympathetic innervation to the lacrimal gland is via the

Greater petrosal branch of CN VII (preganglionic) and the pterygopalatine ganglion (post ganglionic)


The parasympathetic innervation to the constrictor pupillae and ciliary muscles is via

CN III (preganglionic) and ciliary ganglion (post ganglionic)


The ciliary ganglion contains cell bodies of

Post ganglionic parasympathetic neurons


Preganglionic parasympathetic axons from CN III enter the ciliary ganglion through the

Motor root


The post ganglionic axons then leave the ciliary ganglion through the short ciliary nerves and to the eyeball to innervate the

Sphincter pupillae and cilliary muscles


Contains sensory fibers from CN V1 and postganglionic sumpathetic axons from cell bodies in the superior cervical ganglion that pass through wihtout synapsing

Ciliary ganglion


What is the sensory nerve in the orbit for special sensation?

Optic nerve (II)


What is the sensory nerve in the orbit for general sensation?

Opthalmic (V1) and maxillary (V2) divisions of the trigeminal nerve


The eyeball receives general sensory innervation from the

Long ciliary and short ciliary nerves, which are branches of the nasociliary nerve (branch of V1)


Pass through the ciliary ganglion on their way to the eyeball

Sensory fibers in short ciliary nerve


What are the other sensory nerves that pass through the orbit to provide general sensory innervation to the face, paranasal sinuses, and cranial cavity?

Frontal nerve, lacrimal nerve, infraorbital nerve, and zygomaticotemporal and zygomaticofacial nerves


All of the sensory fibers of the trigeminal nerve have their cell bodies in the trigeminal ganglion located in the

Middle cranial fossa


Prior to entering the orbit, CN V1 divides into the

Lacrimal, frontal, and nasociliary nerves


Within the orbit, the frontal nerve divides into the

Supraorbital and supratrochlear nerves


Gives rise to the Sensory root of the ciliary ganglion, the long ciliary nerve, the ethmoidal nerves, and the infratrochlear nerve

Nasociliary Nerve


Provides sensation from the eyeball

Sensory root of ciliary ganglion and long ciliary nerve


PRovides sensation from the ethmoid air cells, the anterior cranial fossa, and the nasal cavity

Ethmoidal nerves


Provides sensation from the face

Infratrochlear nerce


Prior to entering the orbit, CN III divides into a

Superior and inferior division


The superior division of CN III carries SOMATIC motor innervation to the

Levator palpebrae superioris and superior rectus


The inferior division of CN III carries somatic motor innervation to the

Inferior and medial rectus and the inferior oblique


The inferior division of CN III also carries preganglionic parasympathetic innervation to the

Ciliary ganglion


CN IV and CN VI enter the orbit and each innervate one muscle, which are they?

CN IV = superior oblique
CN VI = lateral rectus


A branch of the internal carotid artery that enters the orbit through the optic canal along with the optic nerve

Opthalmic artery


Sole blood supply to the visual receptor cells of the retina

-Branch of opthalmic artery

Central artery of the retina


Communicates with several veins of the face, receives tributaries within the orbit, and then exits the orbit through the superior orbital fissure to enter the cavernous sinus

Superior opthalmic vein


Receives tributaries within the orbit and then divides into two branches

Inferior opthalmic vein


One branch exits the orbit through the inferior orbital fissure to drain into the

Pterygoid plexus in the infratemporal fossa


The other branch drains into the

Superior opthalmic vein


Usually the pressure gradient of the opthalmic veins is such that blood flow is from

Within the cranial cavity outward


Can travel to the cavernous sinus and may lead to septic cavernous sinus thrombosis (potentially fatal)

Superficial cutaneous infection of the face


Which structures passTHROUGH the common ring tendon of the four rectus muscles?

1.) CN II
2.) CN III (sup. & inf.)
3.) CN VI
4.) Nasociliary nerve of V1
5.) Opthalmic artery


What are the structures that pass OUTSIDE of the ring tendon?

1.) CN IV
2.) Frontal and lacrimal nerves of V1
3.) Infraorbital and zygomatic nerves of V2
4.) Opthalmic veins

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