cranial nerves Flashcards
CN I
Olfactory Nerve
components: SVA
distribution: olfactory mucosa
nuclei: olfactory bulb
Symptoms of CN I dysfunction
anosmia: loss of sense of smell
CN II
Optic Nerve
distribution: retina
symptoms of CN II disruption
blindness
CN III
Occulomotor nerve components: GSE, GSAprop., GVE distribution: EO muscles = med, infer, sup rect, infer oblique, levator palpebrae sup peripheral ganglion = ciliary use/abuse by parasymp ANS
symptoms of CN III disruption
dilation of pupid (mydriasis), ptosis, lateral strabismus, diplopia
CN IV
trochlear nerve midbrain derived (mesencephalon) nuclei: trochlear, mesencephalic of V GSE, GSAprop distribution: EO muscles (sup oblique)
symptoms of CN IV disruption
strabismus (can’t look downward when eye is adducted)
CN V
Trigeminal
hindbrain derived (metencephalon), pons
nuclei: motor of V (SVE), mesencephalic of V, principle sensory, spindle trigeminal
GSAext., GSAprop, SVE (pouch I)
distribution = mastication muscles (tensor typmani, tensor veli palatine, mylohyoid, anterior digastric)
peripheral ganglion (trigeminal)
use/abuse by sympathetic NS
symptoms of dysfunction
anesthesia of face, asymmetric chewing, biting
CN VI
Abduces Nerve hindbrain derived (metencephalon), pons Nuclei: abducens, mesencephalic of V GSE, GSA components distribution: EO muscles (lateral rectus)
symptoms of CN VI disruption
strabismus (can’t abduct eye - pupil is inward)
CN VII
Facial Nerve (“Great motor nerve of the face”)
hindbrain derived (metencephalon), pons, medulla
nuclei: facial motor nerve of VII (SVE), mesencephalic of V, sup salvitory, solitary, spinal trigeminal of V
SVE, FVA, FVE, SVA, GSAprop, GSAext
Distribution: facial expression muscles, salivary glands, taste anterior of 2/3 of tongue, lacrimal glands, nasal lorae mucosa, stapedius, posterior digastric, stylohyoid
use/abuse by parasymp ANS
peripheral ganglion - submandibular and PP ganglion
symptoms of CN VII disruption
facial paralysis, loss of taste, dry eyes, loss of salivation, anesthesia of face, loss of cutaneous from ear
CN VIII
Vestibulocochlear nerve (hearing and balance)
hindbrain (metencephalon), pons and medulla
nuclei: vestibular, cochlear
SSAprop, SSA extero
distribution: semicircular canals, utricle, saccule, spiral organ of corti
peripheral ganglia
symptoms of CN VIII disruption
dysequillibrium, nystagmus, deafness
CN IX
glossopharyngeal nerve
hindbrain derived (metencephalon), pons and meduclla
nuclei: solitaries, ambiguous, spinal V, mesencephalic V
GVE, SVE, GVA, SVA, GSAprop, GSAextero
distribution: middle ear mucosa, salivation, parotid gland, pharynx
peripheral ganglia: sup and inf (petrosal)
use/abuse by parasympathetic ANS
Symptoms of CN IX disruption
loss of taste at posterior 1/3 of tongue, salivation, elevated BP, tachycardia, loss of gag reflex, upper pharynx anesthesia
CN X
Vagus Nerve (nerve of thoracic and abdominal cavities)
hindbrain derived (metencephalon), pons & medulla
nuclei: dorsal motor of X, solitaries, ambiguous, spinal V, mesencephalic V
GVE, SVE, GVA, SVA, GSAprop, GSAextero
distribution: cervical, thoracic, abdominal regions, salivation, pharynx, larynx, palate, epiglottis, root of tongue, ear, aortic bodies and sinus, carotid bodies
peripheral ganglia: superior (jugular), inferior (nodose)
use/abuse by parasympathetic ANS
Symptoms of CN X disruption
taste of root of tongue loss, visceral disturbances, loss of peristalsis, hoarseness, dysphonia, dysphagia, tachycardia, loss of cough reflex, loss of vomit reflex, anesthesia of external ear
CN XI
Spinal Accessory Nerve
hindbrain derived (metencephalon), pons & medulla
nuclei: ambiguous, cervical spinal nuclei, mesencephalic V
GSE, SVE, GSAprop
distribution of cranial part (SVE): arises from cells in the most caudal part of the N. ambiguous, joins the vagus nerve to for the inf. (recurrent) laryngeal N. to innervate the larynx, palatine, and pharyngeal muscles
distribution of spinal part (GSE): innervates the same side trapezius and sternocleidomastoid
symptoms of CN XI disruption
weakness of trapezius and SCM on ipsilateral side
CN XII
Hypoglossal Nerve
hindbrain derived (metencephalon), pons & medulla
nuclei: hypoglossal nucleius, mesencephalic V
GSE, GSAprop
distribution: skeletal muscle of tongue
symptoms of CN XII disruption
unilateral loss produces ipsilateral LMN paralysis, tongue deviates to same side as lesion when protruded
