Cranial nerves Flashcards
CN1 - What is it , what does it do and how do you test it
CN1 - Olfactory nerve
- Sense of smell
- Ask for change in smell
CN2 - What is it and what does it do
CN2 - Optic nerve
- Conveys vision
How do you test CN2
- Visual acuity (Snellen chart)
- Pupillary reflex (CN2 & 3)
- Visual fields
- Visual inattention
- Visual accomodation
- Fundoscopy
CN3 - what is it and what does it do
CN3 - oculomotor nerve
Motor supply to:
- superior, medial and inferior rectus muscles
- inferior oblique
- levator palpebrae superioris muscles
Also parasympathetic innervation of constrictor pupillae (pupil size) and ciliary muscle (accommodation)
How do you test CN3
Pupillary reflex Eye movements (CN3, 4, 6)
What is CN4, what does it do and how do you test it
CN4 - Trochlear nerve
Motor - superior oblique muscle of eye (internal rotation)
Eye movements (CN3,4,6)
What is CN5 and what does it do?
CN5 - Trigeminal
Sensory:
- V1 (ophthalmic) = forehead
- V2 (maxillary) = cheeks
- V3 (mandibular) = jaw
Motor:
- V3 - masseter & pterygoid
How do you test CN5?
Test sensation of L&R - Forehead, cheeks & jaw
Palpate masseter while jaw clenched
Open jaw against resistance
Corneal reflex (CNV1 afferent & CNVII efferent)
What is CN6 function & test
CN6 - abducens nerve
Motor - lateral rectus muscle of eye (abducts the eye)
Test - eye movements (CN3,4,6)
CN7 - name, function & test
CN7 - Facial nerve
Motor - muscles of facial expression
Secretomotor - submandibular and sublingual glands
Taste - anterior 2/3rds tongue
Tests:
- Inspection - asymmetry (bells palsy)
- Facial movements (motor function)
- +/- taste
CN8 - name, function & test
CN8 - vestibulocochlear nerve
Vestibular - equilibrium & balance
Cochlear - hearing
Vestibular - Nystagmus (during eye movements testing)
Cochlear - Whisper test, Rinne’s & weber’s
CN9 - name, function & test
CN9 - Glossopharyngeal
Sensory - pharynx and tonsils
Taste (& sensation) - posterior 1/3 of tongue
Motor - stylopharyngeus muscles
Inspection of back of throat while saying ‘aah’
Cough
Gag reflex (CN9 & 10)
CN10 - name, function & test
CN10 - Vagus nerve
Motor & sensory of:
- paletine, pharyngeal and laryngeal muscles
- a lot more
Inspection of back of throat while saying ‘aah’
Cough
Gag reflex
CN11 - name, function & test
CN11 - accessory nerve
Motor to upper trapezius & SCM
Shrug shoulders
Turn neck against resistance
CN12 - name, function & test
CN12 - hypoglossal
Innervates muscles of tongue
Inspection of tongue - fasciculations etc
Wiggling of tongue
Speech
