15-B Orbit Nerves, Blood Supply and Lacrimal

Question 1

Which nerve carries branchiomotor innervation to the orbit, and via what branches?

Answer 1

the temporal and zygomatic branches of the facial nerve provide innervation to the oribicularis oculi

Question 2

What nerve carries special somatosensory innervation to the eye?

Answer 2

optic nerve

Question 3

Which nerves provide somatomotor innervation to the orbit?

Answer 3

oculomotor n.
trochlear n.
abducens.

Question 4

Describe the branches of CN III

Answer 4

the oculomotor nerves branches into the superior branch of III carrying sympathetics and an inferior branch of III carrying parasympathetics

Question 5

Describe the branching pattern of CNV after it leaves the brainstem.

Answer 5

trigeminal forms the trigeminal ganglion after which it divides into its 3 main branches. V1, ophthalmic branch breaks into three branches (NFL) frontal, lacrimal and nasociliary nerves (superficial, lateral and deep/medial)

Question 6

What are the two branches of the frontal nerve?

Answer 6

supratrochlear and supraorbital nerves, which exit the superior portion of the orbit

Question 7

Name the branches of nasociliary nerve and their destinations.

Answer 7

ethmoidal branches (ethmoid plate), long ciliary nerves (directly to eyeball), sensory branches (ciliary ganglion) and short ciliary nerves (eyeball from the ciliary ganglia) and sensory branches (lateral orbit)

Question 8

Describe the path of parasympathetics originating in the oculomotor nucleus.

Answer 8

oculomotor nerve, inferior branch of oculomotor, ciliary ganglion, short ciliary nerves to the pupillary sphincter and ciliary muscle

Question 9

Describe the path of parasympathetics that originate in the superior salivatory nucleus to the lacrimal gland

Answer 9

facial nerve splits into branches and parasympathetic follow greater petrosal (to the pterygoplaatine ganglion) to the lacrimal gland (other branches include the chroda tympani to ciliary ganglia)

Question 10

How do sympathetics reach the eyeball?

Answer 10

lateral horn in spinal cord, superior cervical ganglion, carotid plexus, through ciliary ganglion to the long ciliary nerves or directly via the short

Question 11

How do sympathetics reach the superior tarsal muscle?

Answer 11

after the carotid plexus they join the superior branch of the occulomotor

Question 12

What types of fibers are contained in the nerve of the ptergoid canal?

Answer 12

sympathetic and parasympathetic

Question 13

Compare the ciliary nerves based on their nerve fiber content

Answer 13

same except where long ciliary do not include parasympathetics while short ciliary nerves

Question 14

Name the four branches that stay in the orbit from the ophthalmic artery

Answer 14

lacrimal a., posterior ciliary arteries, central a of retina and muscular arteries

Question 15

Name the four branches of the opthalmic artery that exit the orbit.

Answer 15

supratrocholear a. ethmoid a. dorsal a. and supraorbital a.

Question 16

Branches from the ophthalmic a. anastomse with which branch of the external carotid?

Answer 16

middle meningeal a.

Question 17

Which arteries specifically supply the eyeball?

Answer 17

central artery of the retina pierces the optic nerve and supplies the retina and the posterior ciliary arteries supply he choroid

Question 18

Central vein of the retina drains where?

Answer 18

directly into the cavernous sinus (typical) or into the superior ophthalmic vein

Question 19

Which veins drain the eyeball blood flow and its two major functions

Answer 19

superior ophthalmic v. and the inferior ophthalmic v. do much to dissipate heat and transport wastes from the high metabolic expenditures oft he eyeball