Flashcards in Session 8 Deck (41):
Where, in the brainstem, do CN 9-12 leave?
Where, in the brainstem, do CN 5-8 leave?
Where, in the brainstem, do CN 2-3 leave?
Where do CN 1 & 2 leave?
What artery supplies CN III?
Posterior communicating artery
How can CN III be damaged by its artery?
What is the action of the Superior Oblique muscle of the eye?
Moves it down & out
Roughly, what is the course of CN III?
Leaves the oculomotor nucleus in the midbrain
Passes along the lateral wall of the cavernous sinus
Passes through the superior orbital fissure
Splits into branches
What effect does CN III have on the eye?
Innervates levator palpabrae superioris (Keeps upper eyelid up)
Constricts the pupil via parasympathetic fibres
Where do the parasympathetic fibres that travel with CN III come from?
Edinger - Westphal nucleus
Hitch hike on the outside of the oculomotor nerve proer
What is the oculomotor nerve proper?
Nerve that comes from the oculomotor nucleus
Sympathetic innervation only
What is the sign of damage to the oculomotor nerve proper?
Eye faces down and out
*Usually due to issues with the blood supply*
What is the sign of damage to the parasympathetic fibres of the oculomotor nerve?
*Usually due to an infection*
What can cause a CN III palsy?
Issues with blood supply
What does CN III innervate?
What does CN IV innervate?
What does CN VI innervate?
What are the 3 separate roots of the Trigeminal nerve in the brainstem?
Does the Trigeminal nerve have autonomic fibres?
No, but it carries some
What ganglion does Vi come from?
Is Vi sensory, motor or both?
Where does Vi exit the cranium?
Foramen superior orbital fissure
What are the 5 branches of Vi?
Is Vii sensory, motor or both?
Where does Vii exit the cranium?
What are the 3 branches of Vii?
Is Viii sensory, motor or both?
Sensory and motor
Where does Viii exit the cranium?
Via the Foramen ovale
What are the 3 branches of Viii?
Where does Viii come from?
The pons in the brain
Is the facial nerve sensory, motor or mixed?
Also has parasympathetic nerve fibres
What are the 2 roots of the facial nerve?
Lateral (nervus intermedius)
What are the 5 branches of the facial nerve?
Where do taste fibres terminate?
In the nucleus solitaris of the medulla
What is important to remember about the frontalis muscle?
Bilateral innervation from CN VII
What are the extra cranial branches of the facial nerve?
5 branches when leaving the parotid gland
What are the intracranial branches of the facial nerve?
Greater petrosal nerve
Nerve to stapedius
What is Bell's palsy?
A facial nerve palsy that is idiopathic and lasts 6 weeks
What is the difference between a Bell's palsy and a facial nerve palsy?
A facial nerve palsy has a known cause and is permanent
How can the facial nerve be damaged by the parotid gland?
Inflammation of the facial nerve as in a sheath
Forceps delivery of a baby can damage in the stylomastoid Foramen