Cranial Nerves Flashcards
What does V1 exit from?
- the Superior Orbital fissure
Where does V2, Maxillary nerve, exit from?
- Foramen Rotundum
Where does V3 exit from?
FORAMEN OVALE
What occurs on CN4, Trochlear, Palsy?
- diplopia when looking down
- difficulty walking downstairs/ reading/ tying shoe lace
What is the axn of the Superior Oblique muscle? What nerve supplies it?
- CN IV, Trochlear Nerve supplies it
- resp. for intorsion of the eye and DEPRESSION of the eye when ADDUCTED
What occurs with CNIII palsy?
- Pupil will be DOWN and OUT
- Dilated
- Ptosis
CNIII supplies what?
- Extrinsic eye muscles (MR, IO, IR, SR)
- SPhincter Pupillae (pupil constriction)
- ciliary muscles (accomodation)
- Levator Palpebrae (elevate to eye lids)
What the Optic nerve exit from?
- the optic canal of the Sphenoid bone
2 major fxns of the Trigeminal nerve?
- FACIAL sensation
2. MASTICATION
3 majors subdivisions of the trigeminal nerve?
V1: OPHTHALMIC N.
V2. Maxillary
V3: Mandibular
What is sensory supply does V1 offer?
Afferent supply to the CORNEA
resp. for the Corneal reflex
What is V2 resp. for? -
pain and T* sensation of the face
What does V3 supply?
- muscles of mastication
(anterior belly of digastric nerve/ tensor velli palatini/ mylohyoid/) - tensor tympani
How does trigeminal nerve palsy look like?
- loss of corneal reflex
- LOSS of facial sensation
- jaw deviation to the affected side
- weak muscles of mastication
Where does CN6 arise from extrcranially?
- SOF
What does CN 6, Abducens nerve. supply?
- Lateral Rectus muscle
How does R CN 6 palsy look on forward gaze and lateral gaze?
- forward gaze: R CN6= Slightly deviated medially
- right gaze: r eye can;t look laterallt
What occurs with CN 6 palsy?
- horizontal DIPLOPIA
What is the course of the Facial nerve through the temporal bone ?
- Enters the temporal bone through the Internal Auditory meatus
- Exists the bone through the stylomastoid foramen
What does the facial nerve supply?
- Motor innervation to the FACIAL muscles
- Lacrimation
- Salivation
- Taste sensation to the ANTERIOR 2/3s of the tongue
- Innervation to the Stapedius muscle
Which glands does the facial nerve supply?
- SUBMANDIBULAR GLANDS
- SUBLINGUAL glands
- LACRIMAL glands
- nasal, palatine, pharyngeal MUCOUS glands
What occurs with CN VII palsy?
- Flaccid paralysis of UPPER and LOWER face
- loss of efferent corneal reflex
- loss of taste
- hyperacusis
Where does the CN8, Vestibulocohlear nerve arise from extracranially?
- internal acoustic meatus
What is the 8th CN resp. for ?
- hearing
- compensatory eye movements
What occurs with CN 8 palsy?
- TINNITUS/ DEAF
- Nystagmus/ vertigo
What neoplastic lesion may cause CN 8 palsy>
- acoustic neuromas
Name the 9th CN.
GLOSSOPHARYNGEAL nerve
What is CN9 resp. for?
- taste AND sensation at posterior 1/3rd
- Swallowing (stylopharyngeus m.)
- Salivation (parotid gland)
- mediates input from CAROTID BODY and SINUS
- SENSATION to oropharynx, EUSTACHIAN tube and MIDDLE ear cavity
What occurs with CN 9 palsy?
- HYPERSENSITIVE carotid sinus REFLEX
2. LOSS of GAG REFLEX
Name three nerves that exit through the Jugular Foramen?
- Cn 9, 10, 11
What is the 10th CN resp. for?
- Phonation (larynx and pharynx m)
- Swallowing (motor to soft palate)
- Viscera innervation (to heart/ abdomen)
- taste sensation at ROOT of tongue and EPIGLOTTIS
- parasympathetic innerv. to smooth muscle of GIT/ TRACHEA/ BRONCHI/ HEART—REGULATES heart
rhythm - sensory to POSTERIOR cranial fossa
What occurs in CN 10 palsy?
- UVULA deviation
- loss of GAG reflex (efferent)
What is the accessory nerve resp. for?
- HEAD AND SHOULDER movement (SCM and TRAPEZIUS)
How does CN 11 palsy appear?
CAN’T turn head to normal side
What is CN XII?
- hypoglossal nerve
What is CN XII resp. for?
What occurs with CN XII palsy?
- TONGUE movement
- tongue deviation to the side of lesion
Where does CN XII exit from extrcranially?
- Hypoglossal canal
