Cranial nerves of PNS

Cranial nerve pnemonic

Oh, Oh, Oh, To Touch And Feel Very Good Velvet Ah Heaven!

Olfactory, Optic, Oculomotor, Trochanter, Trigeminal, Aductens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal

What is cranial nerve I?

olfactory nerve

What is the function of cranial nerve 1?

Function: Special sense of smell

What is the dysfunction of the cranial nerve 1?

hyposmia/anosmia

What would the cranial nerve exam be for cranial nerve 1?

Propose a volatile non-irritating substance (with hidden eyes)

What is cranial nerve II?

Optic nerves

What is the function, dysfunction and cranial exam of Cranial nerve II?

Function: Special sense of sight

Dysfunction: lack of vision and/or absence of pupillary reflex

Cranial nerve exam: menace response; retinal examination;motion tracking; visual placing reaction; pupillary light reflex(with cranial nerve III)

What is cranial nerve III?

oculomotor nerves

What is the function, dysfunction and cranial exam of cranial nerve III?

Function: motor nerve for occular extrinsic muscles (rectusdorsalis, ventralis, and medialis, inferior oblique, levatorpalpebrae superior). It gives an autonomic parasympathetic branch responsible for the pupillary light reflex (myosis orconstriction of the pupil).• Dysfunction: lateral strabismus (the eye is outward), ptosis of the eyelid (the eyelid falls) and/or mydriasis (no constriction of the pupil but dilatation).•

Cranial nerve exam: observe the resting position of the eyes,test the ability to move the eyes by following something. Observe pupillary light reflex.

What is cranial nerve IV (four)

Trochlear nerve

What is function, dysfunction and cranial exam of cranial nerve IV?

Function: motor nerve for the ocular extrinsic muscle(superior oblique muscle) that moves the eyeball ventrally and towards the nose (medially).• Dysfunction: Dorso-medial strabismus (the eye goes dorso-medially, then the dorsal eyeball is rotated laterally).• Cranial nerve exam: observe the resting position of the eyes, test the ability to move the eyes by following something.18

What is cranial nerve V (five)?

trigeminal nerve

What is the function, dysfunction and cranial exam for cranial nerve 5?

Function: sensory nerve of the face (ophtalmic, maxillary,mandibular branches) and motor nerve (mandibular branch)of the masticator muscles.• Dysfunction: atrophy of the masticator muscles and disorder in feeding process, no face sensation.

Cranial nerve exam: resistance to mouth opening (jaw tone);corneal and palpebral reflex, sensation of the face and the nasal mucosa.21

What is cranial nerve VI (six)

Abducens nerve

What is the function, dysfunction and cranial exam for this nerve?

Function: motor nerve for ocular extrinsic muscles (rectus lateralis and rectus caudalis/retractor bulbi).• Dysfunction: medial strabismus (the eye is inward).• Cranial nerve exam: observe the resting position of the eyes, test the ability to move the eyes by following something

What is cranial nerve VII (seven)?

Function: Sensory nerve of the anterior part of the tongue and motor nerve for facial muscles (muscles of facial expression). It also has autonomic branch for nasal glands, lacrimal and salivary (except parotid). • Dysfunction: facial grimace (lip, eyelip or ear ptosis)• Cranial nerve exam: check the symmetry of the face; palpebral, corneal, lip and ear reflexes (Cn V- VII reflexes); test of Schirmer for dry keratitis.

What is the Shirmer test and what is it measuirng?

filter paper put in the corner of eye for a period of time to wick tears. The amount of wick is compared to a standard scale to measure relative amount of lacrimation

What is cranial nerve VIII (eight)?

Vestibulocochlear nerve

What is the function, dysfunction and cranial exam of this nerve?

Function: The cochlear division provides the hearing and the vestibular division is affected in the sense of balance and eye movements.

Dysfunction: does not hear and/or has problems with balance and/or nystagmus and/or abnormal head position and/or rotational compulsive movements. • Cranial nerve exam: clap (hidden eyes); follow the eyes movement; rotation test; adjustment reaction.

What is cranial nerve IX (nine)?

glossopharyngeal nerve

What is the function, dysfunction and cranial exam for this nerve?

Function: Sensory nerve for the back of the tongue and pharynx. Motor nerve for the elevator muscles of the pharynx. It also contains parasympathetic fibers (to the parotid gland).

Dysfunction: abnormal swallowing (dysphagia)•

Cranial nerve exam: look at the swallowing process. Palpate the oropharyngeal region to start a swallowing reflex.

What is cranial nerve X (ten)?

Vagus nerve

What is the function, dysfunction and cranial exam for this nerve?

Function: Sensory nerve for the pharynx, larynx, esophagus, trachea, bronchi, heart, great vessels, abdominal viscera and motor nerve for the pharynx, larynx, and esophagus. Its parasympathetic fibers innervate the smooth muscle of the esophagus, the stomach, intestine and the bronchial tree, and they also innervate the heart. • Dysfunction: dysphagia; chest and abdominal visceral disorders. • Cranial nerve exam: swallowing reflex; gag reflex; occulo-heart reflex

What does vagal indigestion cause in Ruminants?

eructation failure and bloat

rarely truecardiovascular or gastrointestinal signs point directly to vagal nervelesions except in ruminants.

What is megaesophogus a sign of?

Cn X paralysis. This results in regurgitation of formed esophageal masses (tube of food).

What is the only muscle that opens the glottis cleft?

The cricoarytenoideus dorsalis

What does Paralysis of the recurrent laryngeal nerve result in?

"roarers", laryngeal hemiplegia in horses.

What is cranial nerve XI (eleven)

Spinal (accessory) nerves

What is the function, dysfunction and cranial exam for this nerve?

Function: motor nerve for superficial muscles of the neck(omotransversarius, brachiocephalicus, trapezius, sternocephalicus)• Dysfunction: amyotrophy• Cranial nerve exam: observe and palpate the symmetry of muscles on both sides of the neck.56Picture from Pasquini

What is cranial nerve XII (twelve)?

Hypoglossal nerve

What is the function, dysfunction and cranial exam for this nerve?

Function: motor nerve for the tongue muscles. • Dysfunction: unilateral paralysis will cause deviate to the side of the lesion at first and then over time away from the lesion as muscles atrophy.

Cranial nerve exam: pulling the tongue out of mouth.60Picture from Pasquini