Cranial Nerves

Question 1

Cranial Nerves - General definition

Answer 1

They emanate directly from the brain stem, rather than the SC
They have specific tasks rather than regulating a given area of anatomy
12 pairs of nerves, some are sensory, some are motor, some are both
The ‘nerves’ are actually the ganglion - much like the dorsal root ganglion in the SC

Question 2

Why is it important to remember the 12 cranial nerves?

Answer 2

It allows us to determine where an injury site might be by testing functional impairments
Knowing the injury site we can guess the impairments - it’s important to know the impairments in order to prescribe, teach and supervise ex training

There’s a particular impact on sight, smell, taste, hearing and balance

Question 3

Name the 12 cranial nerves:

Answer 3

I - Olfactory
II - Optic
III - Oculomotor
IV - Trochlear
V - Trigeminal
VI - Abducens
VII - Facial
VIII - Vestibulocochlear
IX - Glossopharyngeal
X - Vagus
XI - Accessory
XII - Hypoglossal

Question 4

What are the functions of the 12 cranial nerves?

Answer 4

I - Olfactory = smell
I - Optic = vision
III - Oculomotor = eyelid and eyeball movement, pupil
IV - Trochlear = turns eye down & laterally; innervates superior oblique
V - Trigeminal = chewing; face & mouth touch & pain
VI - Abducens = turns eye laterally
VII - Facial = facial expressions, tears & saliva, taste
VIII - Vestibulocochlear = [auditory]: hearing, equilibrium/balance
IX - Glossopharyngeal = taste, carotid blood pressure
X - Vagus = aortic BP, HR, stimulates digestive organs, taste
XI - Accessory [Spinal] = swallowing, innervates trapezius & sternocleidomastoid
XII - Hypoglossal = controls tongue movement

Question 5

Name the origins of the cranial nerves:

Answer 5

I & II = lobe under cortex, anterior
III & IV = midbrain
V - VIII = pons
IX - XII = medulla oblongata