08 - Oculomotor, Trigeminal & Facial Nerves Flashcards Preview

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

Flashcards in 08 - Oculomotor, Trigeminal & Facial Nerves Deck (18):
0

What are the three sensory branches of the maxillary division of the trigeminal nerve?

Infraorbital, zygomaticofacial, zygomaticotemporal

1

What are the three sensory branches of the mandibular division of the trigeminal nerve?

Auriculotemporal, buccal, mental

2

What is special about the fibres of the oculomotor nerve?

The parasympathetic fibres to the eye travel in the oculomotor nerve, but they are not part of the oculomotor nerve. They hitch-hike along the nerve to innervate the sphincter pupillae muscle of the eye

3

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

4

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

5

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

6

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

7

What is special about the fibres of the trigeminal nerve?

It doesn't give rise to autonomic fibres but carries sympathetic autonomic fibres from the superior cervical ganglion

8

Where does the facial nerve join the brainstem?

At the cerebellopontine angle

9

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

10

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.

11

The facial nerve has intracranial and extracranial branches. What are the extracranial branches?

The five main
Posterior auricular nerve
Branch to posterior belly of the digastric muscle and stylohyoid

12

The facial nerve has intracranial and extracranial branches. What are the intracranial branches?

Greater petrosal nerve
Nerve to stapedius
Chorda tympani

13

As the facial nerve passes through the parotid gland it splits in to five main branches. What are these branches?

Temporal
Zygomatic
Buccal
Mandibular
Cervical

14

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

It divides in to superior and inferior divisions

15

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

16

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

17

What are the five sensory branches of the ophthalmic division of the trigeminal nerve?

Supratrochlear, supraorbital, lacrimal, infratrochlear, external nasal