Cranial Nerves Flashcards
Trigeminal nerve - which component is motor (CN V1, V2 or V3) ?
V3
Trigeminal nerve - which component is Sensory (CN V1, V2 or V3) ?
V1, V2, V3
Ophthalmic division of trigeminal nerve
CN V1
Maxillary division of trigeminal nerve
CN V2
Mandibular division of trigeminal nerve
CN V3
Which CN’s carry parasympathetics ?
CN III, VII, IX, X
Which CNs connect with the forebrain?
CN I
CN II
Which CNs connect with the midbrain?
CN III
CN IV
What is the only CN to connect directly with the pons?
CN V
CN V1, V2, V3
Which CNs connect at the junction between pons and medulla?
CN VI
CN VII
CN VIII
Which CNs connect with the medulla?
CN IX
CN X
CN XII
Which CNs connect with the SC ?
CN XI
CN I - function
Smell (special sensory)
CN I - base of skull foraminae
Cribriform plate of ethmoid bone
CN I is the only nerve in the anterior cranial fossa. True or false?
True
CN I - where is it found intracranially
Olfactory bulb
CN I - testing
Ask patient to smell a familiar strong smell whilst covering contralateral nostril
A frontal lobe tumour would not affect CN I. True or false?
False
- it could
CN II - function
Vision
CN II - base of skull foramina
Optic canal
CN II is in the anterior cranial fossa. True or false?
False
- middle
CN II - intracranial part
Optic nerve -> optic chiasma -> optic tract
CN II - connection with CNS
Diencephalon
CN II - testing
Acuity (snellen chart ) Colour (ishihara plate) Fields (4 quadrants) Reflexes Fundoscopy
CN III - function
Eye movement (MR, SR, IR, IO, LPS) Pupil constriction (parasympathetic)
CN III - base of skull foramina
Superior orbital fissure
CN III - testing
Eye movements
Pupil response to light
CN IV - function
Supplies SO eye muscle
CN IV - base of skull foramina
Superior orbital fissure
Which CNs travel towards the orbit in the lateral wall of the cavernous sinus?
CN III, IV, VI
What is the only CN that arises posterior from the brain?
CN IV
CN IV has a very short course. True or false?
False
- very long course
CN V1 - base of skull foramina
Superior orbital fissure
CN V2 - base of skull foramina
Foramen rotundum
CN V3 - base of skull foramina
Foramen ovale
CN V1 - functions
Supply sensation to: Forehead Upper eyelid Cornea Conjunctiva Skin of the root/bridge/ tip of nose
Deep sensory territory: Bones and soft tissues of orbit Upper anterior nasal cavity Paranasal sinuses (apart from maxillary sinus) Anterior and posterior cranial fossae
CN V2 - functions
Supply sensation to: Central part of face Lower eyelid Skin over maxilla Skin over ala of nose Skin of upper lip
Deep sensory territory: Lower posterior nasal cavity Maxilla and maxillary sinus Floor of nasal cavity/palate Maxillary teeth
CN V3 - sensory functions
Supply sensation to:
Skin over mandible and TMJ
Chin
Deep sensory territory: Mandible Anterior 2/3rds tongue Floor of mouth Buccal mucosa Mandibular teeth
What supplies the skin over the angle of the mandible?
Greater auricular nerve (C2,3)
CN V3 - motor functions
Muscles of mastication
Name the jaw opening muscle(s)?
Lateral pterygoid
Name the jaw closing muscle(s) ?
Medial pterygoid
Masseter
Temporalis
CN V - testing sensation
Ask patient to close eyes
Gently brush skin in each dermatome with a fine tip of cotton wool
Tell patient to tell you when they feel skin being touched
Compare 2 sides
CN V - motor component testing
Palpate strength of contraction of the master and temporals by asking patient to clench teeth
ask patient to open jaw against resistance
What is the role of pontine trigeminal nucleus ?
Discriminative touch, vibration