Cranial nerves Flashcards
How many cranial nerves are there?
12 pairs
What do parasympathetic nerves innervate?
Glands, smooth muscle
Is there any sympathetic outflow from the skull?
No
What nerve fibres are present in olfactory nerve?
Special sensory
What nerve fibres are present in optic nerve?
Special sensory
What nerve fibres are present in oculomotor nerve?
Motor
Parasympathetic
What nerve fibres are present in trochlear nerve?
Motor
What nerve fibres are present in trigeminal nerve?
Motor
Sensory
What nerve fibres are present in abducens nerve?
Motor
What nerve fibres are present in facial nerve?
Motor
Sensory
Parasympathic
What nerve fibres are present in vestibulocochlear nerve?
Special sensory
What nerve fibres are present in glossopharyngeal nerve?
Sensory
Motor
Parasympathetic
What nerve fibres are present in vagus nerve?
Sensory
Motor
Parasympathetic
What nerve fibres are present in spinal accessory nerve?
Motor
What nerve fibres are present in hypoglossal nerve?
Motor
Where does the olfactory nerve fibres pass through the skull?
Cribiform plate of ethmoid
What is the name for lost sense of smell?
Anosmia
An increase in ICP can result in which eye condition?
Papillodema
A lesion at the optic chiasm will result in what type of visual field loss?
Bitemporal hemianopsia
A lesion at the right optic tract will result in what type of visual field loss?
left homonymous hemianopsia
Which foramen does the optic nerve pass through?
Optic foramen
Where do the retinal nerve fibres synapse?
Lateral geniculate body
Where does the oculomotor nerve originate?
Midbrain
Where does the oculomotor emerge from the skull?
Superior orbital fissure
What does the oculomotor supply in the eye?
Extraocular muscles & eyelid Constricts pupil (circular muscles) & accommodates lens (ciliary muscle)
If the oculomotor is lesioned, what will be observed?
Ptosis (eyelid drooping)
Eyeball abducted and pointing down
No pupillary reflex
No accommodation
Where does the trochlear nerve exit the skull?
Superior orbital fissure
What does the trochlear nerve supply?
Superior oblique (turns eye down)
What happens is the trochlear nerve is lesioned?
Diplopia (On looking down)
Where does the abducent nerve originate?
Pons
Where does the abducent nerve exit the skull?
Superior oblique fissure
What does the abducent nerve supply?
Lateral rectus muscle
If the abducens nerve is lesioned what happens?
Medial deviation of eye causing diplopia
Where does the trigeminal emerge from?
Pons
Where does the trigeminal (ophthalmic) nerve exit the skull?
Superior orbital fissure
What does V1 supply?
Sensory to cornea, forehead, scalp, eyelids & mucosa of nasal sinuses
Where does the V2 division of the trigeminal nerve exit the skull?
Foramen rotundum
What does the V2 nerve supply?
Sense to the face of maxilla, teeth, TMJ joint & mucosa of maxillary sinuses
Where does the V3 branch of trigeminal nerve exit the skull?
Foramen ovale
What does the V3 branch of the trigeminal supply?
Sense to mandible, mucosa of mouth & anterior 2/3rds of tongue
Muscles of mastication
If the trigeminal nerve is lesioned what are the clinical signs?
Paralysis of muscles of mastication
loss of corneal reflex
loss of face sensation
trigeminal neuralgia
Where does the facial nerve originate?
Pontomedullary junction
Where does the facial nerve travel?
Internal acoustic meatus and out via the stylomastoid foramen
What does the facial nerve supply?
Muscles of facial expression
Innervation of submandibular & submental salivary glands
taste to anterior 2/3rd of tongue
General sensory - external acoustic meatus
If the facial nerve is lesioned what clinical signs can be observed?
Bell’s palsy (cannot close eyelid, drooping of mouth)