Gross Anatomy 4 - Cranial Nerve Clinical Testing Flashcards
What type of fibres does the olfactory nerve (CN I) contain?
Special sensory
What type of fibres does the optic nerve (CN II) contain?
Special sensory
What type of fibres does the oculomotor nerve (CN III) contain?
Motor (somatic motor and parasympathetic)
What type of fibres does the trochlear nerve (CN IV) contain?
Motor
What type of fibres does each of the trigeminal nerve branches (CN V) contain?
CN V1 and V2 = sensory only
V3 = sensory and motor
What type of fibres does the abducent (CN VI) nerve contain?
Motor
What type of fibres does the facial nerve (CN VII) contain?
Special sensory
Sensory
Motor (Somatic and parasympathetic)
What type of fibres does the vestibulocochlear nerves (CN VIII) contain?
Special sensory
What type of fibres does the glossopharyngeal nerve contain (CN IX)?
Special sensory, sensory, visceral afferent
Motor - somatic motor and parasympathetic
what type of fibres does the vagus nerve nerve (CN X) contain?
Sensory, visceral afferent
Motor - somatic motor and parasympathetic
What type of fibres does the spinal accessory nerve contain (CN XI)?
Motor
What type of fibres does the hypoglossal nerve (CN XII) contain?
Motor
What is the full name for CN V1?
Ophthalmic division of the trigeminal nerve
What is the full name for CN V2?
Maxillary division of the trigeminal nerve
What is the full name for CN V3?
Mandibular division of the trigeminal nerve
Where does the trigmeninal nerve (CN V) connect to the CNS?
At the pons (only CN to attach here)
What is the intracranial course of the trigeminal nerve?
Inferior to the edge of the tentorum cerebelli between the posterior and middle cranial fossa
Which bone are the foramina for the trigeminal nerve (CN V) located in?
Sphenoid bone
Which base of skull foramina does CN V1 pass through?
Superior orbital fissure
Which base of skull foramina does CN V2 pass through?
Foramen rotundum
Which base of skull foramina does CN V3 pass through?
Foramen ovale
What superficial sensory function does CN V1 have?
Provides sensory innervation to the forehead, upper eyelid, cornea, all the conjunctiva, skin of the root/ bridge/ top of the nose
What superficial function does CN V2 have?
Provides sensory information from the skin of the lower eyelid, skin over the maxilla,skin of the ala of the nose, skin/ mucosa of the upper lip
What superificial sensory function does CN V3 have?
Provides sensory information from the skin over the mandible and TMJ (apart from the angle of the mandible)
What nerve provides sensory information from the angle of the mandible and some of the external ear?
Spinal nerves?
What is this a branch of
Great auricle nerve (C2, 3)
Sensory branch of the cervical plexus
Where is the trigeminal sensory ganglion located?
In the middle cranial fossa
What deep sensory function does CN V1 have? (4)
Bones and soft tissue of the orbit (except orbital floor and lower eyelid)
Superior anterior nasal cavity
All paranasal sinuses (except the antrum)
Anterior and posterior cranial fossae
What deep sensory function does CN V2 have? (4)
Lower posterior nasal cavity
Maxilla and maxillary sinus
Floor of the nasal cavity/ palate
Maxillary teeth and associated soft tissues
What deep sensory function does CN V3 have? (6)
Middle cranial fossa Mandible Anterior 2/3rds of the tongue Floor of the mouth Buccal mucosa Mandibular teeth and associated soft tissues
What group of muscles does CN V3 innervate?
Muscles of mastication
Tensor veli palatini
Tensor tymapni
What are the 3 pairs of jaw closing muscles innervated by CN V3?
Masseter
Temporalis
Medial pterygoid
What is the name of the jaw opening muscle innervated by CN V3?
Lateral pterygoid
Attachments of masseter?
Angle of mandible
Zygomatic arch
Attachments of temporalis?
Coronoid process of mandible
Lateral aspect of the neurocranium
Attachments of medial pterygoid?
(Medial side of) angle of mandible
Pterygoid plates of sphenoid bone
Attachments of lateral pterygoid?
Condyle of mandible and articular disc of TMJ
Pteryoid plates of sphenoid bone
What are the key points for testing CN V1? (3)
Forehead
Upper eyelid
Tip of nose
What are the key points for testing CN V2? (4)
Mid-cheek
Lower eyelid
Upper lip
Nostril of nose
What are the key points for testing CN V3? (3)
Mid-cheek, lower lip and chin
How do you test the motor function of the trigmeninal nerve?
Palpate the strength of contraction of the master and temporals by asking the patient to clench their teeth
Ask the patient to open their jaw against resistance
where does the facial nerve connect to the CNS?
Anterolaterally at pontomedullary junction
What is the intracranial course of the facial nerve?
Directly into internal acoustic meatus in the posterior cranial fossa
What bone does the facial nerve pass through?
Temporal bone
What foramina does the facial nerve pass through in the base of the skull?
Internal acoustic meatus
Stylomastoid foramen
What is the extra cranial course of the somatic motor axons of the facial nerve?
Most of the axons pass into the parotid gland then into 1 of the 5 branches that supply the muscles of facial expression
What is the name of the canal that connects the internal acoustic meatus to the stylomastoid foramen?
Facial canal (facial nerve passes through this)
What bone is the facial canal located in?
Petrous temporal bone
What is the name of the muscle in the ear that is supplied by the facial nerve?
Stapedius
What is the function of stapedius?
Reduces stapes movement to protect the internal ear from excessive noise
What nerve is the chorda tympani a branch of?
Facial nerve
What does the chorda tympani supply?
Taste buds of the anterior 2/3rds of the tongue
Parasympathetic supply to the submandibular and sublingual salivary glands
What nerve does the chorda tympani join with?
CN V3
Name of the muscle of facial expression at the forehead?
Frontalis
Name of the muscle of facial expression around the eyes?
Obicularis oculi
Name of the muscle of facial expression between orbicularis oculi and orbicularis oris?
Elevator of lips
Name of the muscle of facial expression around the lips?
Orbicularis oris
What actions can you ask a patient to do in order to test the motor function of CN VII?
Frown
Close eyes tightly
Smile
Puff out cheeks
What is the anatomical name for the border of the lips?
Vermillion border
What type of fibres does the glossopharyngeal nerve (CN IX) carry?
Special sensory Somatic sensory Somatic motor Visceral afferent Parasympathetic
Where does CN IX attach to the CNS?
Lateral aspect of the medulla oblongata
Intracranial course of the glossopharyngeal nerve?
Directly towards jugular foramen in the posterior cranial fossa
Where does the glossopharyngeal nerve pass through the base of the skull?
At the junction between the temporal been and occipital bone via the jugular foramen
What does the glossopharyngeal nerve provide general sensory fibres to? (7)
Posterior 1/3d of tongue Mucosa of most of the nasopharynx Mucosa of all of the oropharynx Mucosa of some of the laryngopharynx Palatine tonsil Eustachian tube Middle ear cavity
The general sensory axons from which CN supplies the afferent limb to the gag reflex?
CN IX
What does the glossopharyngeal nerve provide special sensory axons to?
The valet papillae of the posterior 1/3rd of the tongue
What does the glossopharyngeal nerve provide visceral afferent fibres to?
Carotid sinus baroreceptors and the carotid body chemoreceptors
What does the glossopharyngeal nerve provide somatic motor sensation to?
1 of the longitudinal muscles of the pharynx (stylopharyngeus)
What does the glossopharyngeal nerve provide parasympathetic supply to?
The parotid salivary gland
What type of fibres does the vagus nerve contain?
Sensory
Motor
Visceral afferent
Parasympathetic
Where does the vagus nerve connect to the CNS?
Lateral aspect of the medulla oblongata, immediately inferior to CN IX
Describe the intracranial course of the vagus nerve?
Directly towards jugular foramen in the posterior cranial fossa
Where does the vagus nerve pass through the base of the skull?
Junction between the temporal been and occipital bone at the jugular foramen
What does the vagus nerve pass down the neck in?
The carotid sheath
Where does the right branch of the vagus nerve pass in the chest?
Lateral aspect of the trachea
Where does the left branch of the vagus nerve pass in the chest?
Lateral aspect of arctic arch
Where do the branches of the vagus nerve pass in relation to the lung root?
Posterior
How to test the vagus nerve?
Ask the patient to say Ah (also test CNV3) - uvula should lift straight up in midline
Ask the patient to swallow small amount of water
Listen to speech
Ask patient to cough
How does the spinal accessory nerve connect to the CNS?
Via cervical spinal nerve anterior rootlets to the spinal cord
Describe the intracranial course of the spinal accessory nerve?
Ascends through the foramen magnum then travels towards jugular foramen in posterior cranial fossa
Where does the spinal accessory nerve pass through the base of the skull?
At the junction between the temporal bone and occipital bone
Extracranial course of the spinal accessory nerve?
Axons supply sternocleidomastoid on deep surface, then continue across the posterior triangle of the neck deep to the investing fascia and supply the trapezius
How to test the spinal accessory nerves?
Ask patient to shrug shoulders
Ask them to turn head to look up towards the opposite side
How does the hypoglossal nerve attach to the CNS?
Via many rootlets that attach lateral to the pyramids of the medulla oblongata
Describe the intracranial course of the hypoglossal nerve?
Passes anteriorly towards the hypoglossal canal in the posterior cranial fossa
How does the hypoglossal nerve exit the base of the skull?
Via the hypoglossal canal of the occipital bone
How does the hypoglossal nerve descend in the neck?
Lateral to the carotid sheath
What does the hypoglossal nerve do at the level of the hyoid bone?
Pass anteriorly towards the lateral aspect of the tongue
How do you test the hypoglossal nerve?
Ask the patient to stick their tongue straight out
How do you test the optic nerve? (3)
Light reflexes
Visual field testing
Snellen chart
How do you test the oculomotor nerve?
Extra ocular eye movements
How do you test the trochlear nerve?
Down and in eye movement
How do you test the trigeminal nerve? (2)
Facial sensations
Power of muscles of mastication
How do you abducent nerve?
Eye lateral movement
How do you test the facial nerve?
Power of muscles of facial expression
How do you test the vestibulocochlear nerve?
Rhinne’s and Weber’s hearing tests
How do you test the vagus nerve? (2)
Elevation of the soft palate
Normal swallow and speech
How do you test the spinal accessory nerve? (2)
Turning of head and shrugging of shoulders
How do you test the hypoglossal nerve?
Protrusion of the tongue