08 - Oculomotor, Trigeminal & Facial Nerves Flashcards Preview

ENT & Ophthalmology > 08 - Oculomotor, Trigeminal & Facial Nerves > Flashcards

Flashcards in 08 - Oculomotor, Trigeminal & Facial Nerves Deck (9):
0

What is the effect on the pupil if the oculomotor nerve is damaged proximal to the ciliary ganglion?

Fixed dilated pupil due to denervation of the sphincter pupillae and unopposed action of the dilator pupillae

1

What are the anatomical landmarks of the course of the oculomotor nerve?

Lateral wall of the cavernous sinus, uncus (part of the brain) and tentorial notch (thickening of the meninges that partition the intracranial spaces), ciliary ganglion

2

What is the effect on the pupil if the oculomotor nerve is damaged distal to the ciliary ganglion?

The pupils aren't affected = pupil-sparing third nerve palsy

3

What are the effects on the eye if only the parasympathetic fibres from the Edinger-Westphal nucleus?

The extra-ocular muscles are unaffected
Causes dilation of the pupil and loss of the accommodation reflex

4

What are the two roots of the facial nerve?

Lateral root (nervus intermedius) containing sensory fibres from the geniculate ganglion and parasympathetic fibres which hitchhike from the superior salivatory ganglion
Medial root containing only motor axons

5

What is the course of the facial nerve?

From the facial motor nucleus in the pons. Start in the Petrous temporal bone via the internal auditory canal. They pass through the facial canal and exit the cranium through the stylomastoid process. It passes through the parotid gland and splits in to its five major branches.

6

What happens the oculomotor nerve as it passes through the superior orbital fissure?

It divides in to superior and inferior divisions

7

Which branch of the oculomotor nerve is in close proximity to the ciliary ganglion?

Inferior oblique branch of the inferior division of the oculomotor nerve

8

What is Harlequin Syndrome?

Damage to the pre-ganglionic sympathetic fibres that hitchhike on the trigeminal nerve from the superior cervical ganglion
There is sympathetic dysfunction to the regulation of swearing and loss of vasomotor tone to the blood vessels in the head and neck.
It results in anaesthesia, vasomotor dysfunction and anhydrosis on the affected side