CNII Occularmotor

Question 1

What are the origins of the ocular motor nerve? What kind of information do they each carry?

Answer 1

Ocular motor nucleus - motor to extra orbital muscles( lower motor neuron)

Edinger westfall nucleus - parasympathetics for light and accommodation reflexes.

Question 2

Where in the brain are the ocular motor and edinger westfall nuclei?

Answer 2

Midbrain at the level of superior colliculus and anterior portion of periaqueductal gray.

Question 3

Where does the ocular motor nerve exit the brain and the skull?

Answer 3

Brain: interpoduncular fossa
Skull: Superior orbital fissure

Question 4

A lesion of the ocular motor nerve can cause what symptoms?

Answer 4

Lateral strabismus (eye drifts outward)
Ptosis (drooping eyelid)
Madriasis (non-reactive pupil)
Cycloplegia (inability to accommodate)

Question 5

What muscles does the ocular motor nerve innervate?

Answer 5

Mr, Sr, IR, elevator palpebre superiors, IO

Question 6

What is the pathway of parasympathetic and sympathetics go the eye

Answer 6

Parasympathetic: edinger-westfall nucleus exit at interpeduncular fossa as CNIII ➡️ parasympathetic fibers synapse with the cilary ganglion ➡️ fibers travel to sphincter pupillae and ciliaris muscle

Sympathetics: postganglionic fibers from scg join short ciliary nerve and innervate dilator pupilae