Cranial Nerve Exam Flashcards
What is the pathway for a reflex?
afferent nerve, spinal cord/brain stem, efferent nerve
What is the pathway for a response?
afferent nerve, cortex of the brain for perception, initiation of movement by cortex, efferent nerve
What is CN I?
Olfactory n.
How can you test CN I?
offer smelly treat without visualization
What is CN II?
Optic
T/F. the optic n. is both sensory and motor.
F. sensory only
What would happen if CN II is damaged
blindness
What are 5 tests used to test CN2?
- pupillary light reflex
- menace response
- visual placement reaction
- obstacle course
- tracking
What nerve do you also test when using PLR to test CN 2?
CN3
What two nerves do you test when testing a dogs menice response
CN 2 and 7
What if you see a normal menace response but PLR is negative?
Damage to CN 3
What is CN3?
Oculomotor
Which mm. of the eye are innervated by CN3?
Rectus m.
ventral oblique m.
pupil
Where does the oculomotor n. exit the skull?
orbital fissure
how can you test for CN3 damage?
- check for normal eye position
- check for normal uppereyelid position
- PLR
- lesions?
Static deviation of the affected eye
strabismus
drooping of the superior eyelid
ptosis
What is CN IV
Trochlear
Which m. does CN4 innervate?
dorsal oblique
Where does CN4 exit the skull?
Orbital fissure
How can you test CN4?
- abnormal rotation
- normal congruent eye movement
- strabismus
What are the 3 braches of CN5?
- ophthalmic
- maxillary
- mandibular
What is CN5?
Trigeminal
Which branch of the trigeminal n. is sensory to the lateral canthus?
maxillary
What branch of the trigeminal n. is sensory to the medial canthus?
ophthalmic
What is the afferent CN in the palpebral test?
trigeminal
What is the efferent CN being tested when pinching the upper lip/cheak and observing the dog wrinkling its nose?
Facial
What is CN6?
Abducens
What two muscles are innervated by the abducens?
Lateral rectus
Retractor bulbi m.
How can you test CN6?
look for normal eye movement and position
If you touch the cornea and do not see the 3rd eyelid sweep over, which n is damaged?
CN6
Which 3 nn. are responsible for producing coordinated movement of the eyes?
- CN3
- CN5
- CN6
What is CN7?
Facial
How does CN7 leave the dkull?
stylomastoid foramen
T/F. CN7 is both sensary and motor?
t
How can you test the facial n.?
facial symmetry
What are 3 indicators of CN7 damage?
- dec. palpebral reflex
- dec. menace resp.
- dec. response to pinching of upper or lower lip
How can you test the PSNS portion of the facial n.?
tear production amt.
What is the PSNS of CN2?
salivary and lacrimal glands
What is CN8?
Vestibulocochlear n.
What n. functions in hearing and balance
cn8
What would you see if CN8 is damaged?
- dec. hearing
- head tilt
- circling
- nystagmus
A dog comes to you presenting with head tilt due to a lesion to CN8. is his head tilted toward or away from the lesion?
toward
What is CN9?
Glossopharyngeal
CN9 sensory to the ___
Tongue and pharyngeal mucosa
CN9 motor to the ____
Pharynx
CN9 PSNS to the ___
Salivary gland
Where does CN9 exit the skull
Tympanooccipital fissure
How can you test CN9?
- give treat
2. gag reflex
What is CN 10?
Vagus
Sensory of CN10?
epiglottis, ear canal, pharynx, larynx, trachea, esophagus
PSNS of CN10?
Heart, lungs, abdominal viscera
Motor of CN10?
Pharynx and esophagus
how does CN10 exit the skull
Tympanooccipital fissure
What is CN11
Accessory n.
What mm. are innervated by CN11?
Sternocephalicus
cleidocephalicus
trapezius
Omotransversarius
What n. branches off CN11
recurrent laryngeal n.
What is the terminal branch of the recurrent laryngeal n.
Caudal laryngeal
What is the only muscle that open the glottis?
Cricoarytenoidus dorsalis
How does CN 11 exit the skull?
tympanooccipital fissure
What would you observe if CN11 is damaged?
- gait change
- altered head and neck movement
- laryngeal paralysis (roarers)
What is CN12?
Hypoglossal
How does CN12 exit the skull?
hypoglossal canal
What would you observe if CN12 was damaged?
Difficulty eating
tongue offset on unaffected side
dec tongue tone
