Flashcards in Cranial nerves Deck (114)
How many cranial nerves are there?
What do parasympathetic nerves innervate?
Glands, smooth muscle
Is there any sympathetic outflow from the skull?
What nerve fibres are present in olfactory nerve?
What nerve fibres are present in optic nerve?
What nerve fibres are present in oculomotor nerve?
What nerve fibres are present in trochlear nerve?
What nerve fibres are present in trigeminal nerve?
What nerve fibres are present in abducens nerve?
What nerve fibres are present in facial nerve?
What nerve fibres are present in vestibulocochlear nerve?
What nerve fibres are present in glossopharyngeal nerve?
What nerve fibres are present in vagus nerve?
What nerve fibres are present in spinal accessory nerve?
What nerve fibres are present in hypoglossal nerve?
Where does the olfactory nerve fibres pass through the skull?
Cribiform plate of ethmoid
What is the name for lost sense of smell?
An increase in ICP can result in which eye condition?
A lesion at the optic chiasm will result in what type of visual field loss?
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?
Where do the retinal nerve fibres synapse?
Lateral geniculate body
Where does the oculomotor nerve originate?
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
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?
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?
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?
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?
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
Where does the facial nerve originate?
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)
What nerve is the most frequently injured?
Where does the vestibulocochlear nerve originate?
Where does the vestibulocochlear nerve exit the skull?
Internal acoustic meatus
What are the clinical signs observed with a lesion of nerve VIII?
Nystagmus (involuntary rapid eye movements )
Where does the glossopharyngeal nerve originate?
Where does the glossopharyngeal nerve exit the skull?
What does the glossopharnygeal nerve supply?
Taste posterior 1/3rd of tongue
sensation for middle ear & posterior oral cavity
innervation of parotid gland
When the glossopharyngeal nerve is lesioned, what are the clinical signs?
Loss of gag reflex & taste from back of tongue
Where does the vagus nerve exit the skull?
What does the vagus nerve supply?
Taste for epiglottis
parasympathetic innervation of pharynx, larynx, trachea, bronchi, heart & gut
Motor control to the pharynx, larynx, palate & oesophagus
What are some of the branches of vagus nerve?
Recurrent laryngeal nerve
What clinical signs will be observed if the vagus nerve is lesioned?
Where does the spinal accessory nerve exit the skull?
What does the spinal accessory nerve supply?
Sternocleidomastoid & trapezius
If the spinal accessory nerve is lesioned, what clinical signs will be observed?
Weakness in turning head & shrugging shoulder
Where does the hypoglossal nerve exit the skull?
What does the hypoglossal nerve supply?
Muscles of tongue
What clinical signs will be observed if the hypoglossal nerve is lesioned?
Deviation of tongue to affected side
Paralysis & muscle atrophy of tongue
Which nerves are required for taste?
Which nerves are required for movements of face?
Which nerves are required for chewing?
Which nerves are required for swallowing?
Which nerves are required for movements of vocal cords?
Which nerves have visceral sensory input?
Glossopharyngeal (carotid body & sinus)
What are the functions of the cranial nerves?
Which are the nerves of special sense?
I - olfaction
II - vision
XII, IX, X - taste
VIII - hearing
What nerves supply sensation to the ear?
VII & IX
Which nerve supplies muscles of mastication?
Trigeminal (mandibular branch)
Which nerve supplies muscles of facial expression?
Which nerve supplies muscles of pharynx & larynx?
Which nerves supplies SCM & trapezuis?
Which nerves carry parasympathetic innervation?
III, VII, IX, X
What does parasympathetic activity in III nerve mediate ?
What does parasympathetic activity in VII nerve mediate ?
Submandibular & Sublingual salivary gland
What does parasympathetic activity in IX nerve mediate ?
Parotid salivary gland
What does parasympathetic activity in X nerve mediate ?
Organs of abdomen & thorax
What nerves are involved in the pupillary reflex?
II - AFFERENT
What nerves are involved in the corneal reflex?
What nerves are involved in the jaw jerk reflex?
V - afferent & efferent
What nerves are involved in the GAG reflex?
Which cranial nerve nuclei are found in the midbrain?
Which cranial nerve nuclei are found in the pons?
V, VI, VII
Which cranial nerve nuclei are found in the pontomedullary junction?
Which cranial nerve nuclei are found in the medulla?
IX, X, XI, XII
How can cranial nerves be damage?
Crossing sub-arachnoid space (eg. meningitis)
Outside skull, eg tumours
What is the pathology behind optic neuritis? What disease is it associated with?
Demyelination of the optic nerve
What are the signs of optic neuritis?
Monocular vision loss
Pain on eye movement
Reduced visual acuity
Reduced colour vision
Swelling of optic disc
What can cause dilated pupils?
3rd nerve palsy
"Mydriatic" eye drops
Amphetamine & cocaine
Brainstem death (Bilateral)
What cause pupils to constrict?
Miotic eye drops
Horner's syndrome (sympathetic plexus)
What are the microvascular causes of 3rd nerve palsy?
What are the symptoms?
Diabetes & hypertension
Painless & pupil spared
What are the compressive causes of 3rd nerve palsy?
What are the symptoms?
Posterior communicating artery aneurysm
Painful & pupil affected
What are the causes of 6th nerve palsy?
Trigeminal neuralgia presents as painful attacks due to the compression of which nerve?
What is Bell's Palsy?
Idiopathic facial (VII) nerve palsy
What is observed with Bell/s palsy?
Unilateral facial weakness
Inability to close eye
What are some of the LMN causes of facial nerve palsy?
What are some of the UMN causes of facial nerve palsy?
What will be the signs of UMN facial palsy?
The forehead will be spared
What will be the signs of LMN facial palsy?
The whole side of the face will be affected including forehead
What are the symptoms of vestibular neuronitis?
Sudden onset of vertigo
What is dysarthria?
What is dysphonia?
Loss of volume of speech
What is dysphagia?
What is the difference between bulbar palsy & pseudo bulbar palsy?
Pseudobulbar = UMN
Bulbar = LMN
What is the pathology of Pseudobulbar palsy?
Bilateral vascular lesion of the internal capsule
What are some of the symptoms/ signs of pseudo bulbar palsy?
Spastic immobile tongue
Brisk jaw & gag reflex
What nerves does bulbar palsy affect?
Where is the lesion in bulbar palsy?
Bilateral lesion of LMN in brainstem