Cranial Nerves Flashcards
What is the 7th (VII) cranial nerve and does it have sensory, motor or both functions?
Facial, both
What is the route of CN VII?
It travels through the internal acoustic meatus exiting the skull through the stylomastoid foramen
How many branches of CN VII are there?
3 in the ear
and 5 in the face after passing through the parotid gland
What are the branches of CN VII in the face?
Temporal Zygomatic Buccal Mandibular Cervical
What is the 10th (X) cranial nerve and does it have sensory, motor or both functions?
Vagus, both
What is the motor function of CN VII?
Supply the muscles of facial expression and the stapedius muscles of the middle ear
What is the sensory function of CN VII?
Sensory to the anterior 2/3 of the tongue providing taste sensation
What other function does CN VII have excluding motor and sensory?
Provides parasympathetic fibres to salivary glands
What is the 9th (IX) cranial nerve and does it have sensory, motor or both functions?
Glossopharyngeal, both
What is the motor function of CN IX?
Motor to stylopharyngeus to shorten and widen pharynx and elevate larynx
What are the 2 main sensory functions of CN IX?
- Provides taste and general sensation to the posterior 1/3rd of the tongue
- Supplies the carotid sinus and carotid body which helps to control blood pressure, pulse and respiration
What parasympathetic function does CN IX have?
Provides parasympathetic innervation to the parotid gland
What is the motor supply of CN X?
Motor to majority of muscles of pharynx and larynx by recurrent laryngeal or external branch of superior laryngeal nerve
What is the sensory function of CN X?
Sensory to larynx
What is the parasympathetic function of CN X?
Parasympathetic to internal viscera up to 2/3rds of the transverse colon
What is the acoustic reflex?
Loud noise is heard in outer ear, vibrations travel and hit tympanic membrane, vibrations hit ossicles of the ear (malleus, incus and stapes), stapedius muscle contracts to prevent inner ear damage
What is the 5th (V) cranial nerve and does it have sensory, motor or both functions?
Trigeminal, both
What are the branches of CN V?
V1 - Ophthalmic
V2 - Maxillary
V3- Mandibular
What is the sensory function of CN V?
Innervates the skin, mucous membranes and sinuses of the face
How do you test cranial nerve IX and X?
By assessing the soft palate and testing the gag reflex
How do you test cranial nerve V and its branches?
Light touch on the forehead, cheek and jaw
How do you test cranial nerve VII?
Test muscles of facial expression. Ask them if they have noticed any hearing changes
How do you test cranial nerves III, IV and VI?
Look to see if there is any eyelid drooping and ask the patient to follow a H shape with their eyes only
