Innervation

Question 1

Sensory innervation of the eye is by

Answer 1

CN V (Trigeminal) - this is the main one 
CN II (ON)

Question 2

Divisions of the Trigeminal nerve

Answer 2

1. Ophthalmic (V1)
   - Nasocilliary
   * infratrochlear nerve (UL, LL)
   - Frontal
   * Suppratrochlear nerve (UL)
   * Supraorbital nerve (UL)
   - Lacrimal (UL)
2. Maxillary (V2)
   - Infraorbital (LL)
3. Mandibular (V3)

Question 3

Motor innervation by the orbicularis oculi muscle by CN VII (facial nerve)

Answer 3

The temporal and zygomatic branches of the facial nerve innervate the orbicularis ocuili muscle. This muscle is voluntary and protracts to close the eye.

Question 4

Motor innervation by the levator muscle

Answer 4

CN III Oculomotor

Question 5

Which nerve innervates the orbicularis oculi

Answer 5

CN VII (facial)

Question 6

How does the CN III innervate the levator muscle

Answer 6

The superior division of the CN III innervates the levator. The lavator is voluntary- keeping eye open.

This causes the levator to open the eye by retraction.

Question 7

Mullers muscle is innervated by what

Answer 7

Sympathetic fibers because it is a smooth muscle AKA involuntary of the autonomic sympathetic nervous system.

It’s job is to keep the LL open by retraction.