Nerves of Orbit Anatomy
1. Trochlear nerve (IV)
2. Ophthalmic nerve (V1)
3. Optic nerve (II)
4. Oculomotor nerve (III)
5. Abducent nerve (VI)
6. Trigeminal (semilunar) ganglion
7. Frontal nerve
8. Lacrimal nerve
9. Supra-orbital nerve
Comment: The sensory innervation to the orbit arises from
the ophthalmic division of the trigeminal nerve. The major nerves of this
division include the nasociliary, frontal, and lacrimal nerves. The sensory
nerve cell bodies reside in the trigeminal (semilunar) ganglion.
The motor innervation of the
extra-ocular muscles comes from the oculomotor, trochlear, and abducent nerves.
The optic nerve leaves the orbit via
the optic canal. CN III, CN IV, CN V1, and CN
VI traverse the superior orbital fissure.
Clinical: The ophthalmic division of the trigeminal nerve (CN
V1) is the smallest division of CN V. In addition to its sensory role and,
similar to the other 2 divisions of the trigeminal nerve, this division carries
autonomic fibers to the eyeball via its nasociliary nerve and connections to
the ciliary ganglion (long and short ciliary nerves). Additionally, it carries
parasympathetics from the facial nerve (CN VII) that join the lacrimal branch
and innervate the lacrimal glands, which produce tears that moisten the cornea
of the eyeball. Orbital trauma or infections in this confined compartment may
affect these important autonomic pathways.
