Orbit and Extraocular Muscle Testing Pt. 2

Question 1

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

Answer 1

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

Question 2

Of these 5, which two only get SYMPATHETIC innervation?

Answer 2

Dilator pupillae and levator palpebrae

Question 3

Of these 5, which two receive only PARASYMPATHETIC innervation?

Answer 3

constrictor pupillae and ciliary

Question 4

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

Answer 4

Lacrimal gland

Question 5

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

Answer 5

Superior cervical ganglion

Question 6

The preganglionic sympathetic fibers arrise from

Answer 6

T1

Question 7

The parasympathetic innervation to the lacrimal gland is via the

Answer 7

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

Question 8

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

Answer 8

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

Question 9

The ciliary ganglion contains cell bodies of

Answer 9

Post ganglionic parasympathetic neurons

Question 10

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

Answer 10

Motor root

Question 11

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

Answer 11

Sphincter pupillae and cilliary muscles

Question 12

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

Answer 12

Ciliary ganglion

Question 13

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

Answer 13

Optic nerve (II)

Question 14

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

Answer 14

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

Question 15

The eyeball receives general sensory innervation from the

Answer 15

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

Question 16

Pass through the ciliary ganglion on their way to the eyeball

Answer 16

Sensory fibers in short ciliary nerve

Question 17

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

Answer 17

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

Question 18

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

Answer 18

Middle cranial fossa

Question 19

Prior to entering the orbit, CN V1 divides into the

Answer 19

Lacrimal, frontal, and nasociliary nerves

Question 20

Within the orbit, the frontal nerve divides into the

Answer 20

Supraorbital and supratrochlear nerves

Question 21

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

Answer 21

Nasociliary Nerve

Question 22

Provides sensation from the eyeball

Answer 22

Sensory root of ciliary ganglion and long ciliary nerve

Question 23

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

Answer 23

Ethmoidal nerves

Question 24

Provides sensation from the face

Answer 24

Infratrochlear nerce

Question 25

Prior to entering the orbit, CN III divides into a

Answer 25

Superior and inferior division

Question 26

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

Answer 26

Levator palpebrae superioris and superior rectus

Question 27

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

Answer 27

Inferior and medial rectus and the inferior oblique

Question 28

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

Answer 28

Ciliary ganglion

Question 29

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

Answer 29

CN IV = superior oblique | CN VI = lateral rectus

Question 30

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

Answer 30

Opthalmic artery

Question 31

Sole blood supply to the visual receptor cells of the retina -Branch of opthalmic artery

Answer 31

Central artery of the retina

Question 32

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

Answer 32

Superior opthalmic vein

Question 33

Receives tributaries within the orbit and then divides into two branches

Answer 33

Inferior opthalmic vein

Question 34

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

Answer 34

Pterygoid plexus in the infratemporal fossa

Question 35

The other branch drains into the

Answer 35

Superior opthalmic vein

Question 36

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

Answer 36

Within the cranial cavity outward

Question 37

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

Answer 37

Superficial cutaneous infection of the face

Question 38

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

Answer 38

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

Question 39

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

Answer 39

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