28-CranialNerves Flashcards
G__
general - distributed through the whole body
S__
special - restricted area of the body (eg taste buds)
V
visceral - visceral, taste, smell
S
somatic - supplying structures in body wall, eg skin, muscle, joints
__A
afferent
__E
efferent
GSA
general somatic afferent - pain, touch, temperature
SVA
special visceral afferent - smell, taste
GVA
general visceral afferent - mechanoreceptors, nociceptors in viscera
GSA cranial nerves (x4)
V (trigeminal), VII (vestibolocochlear), IX (glossopharyngeal), X (vagus)
SVA cranial nerves (x4)
I (olfactory), VII (facial), IX (glossopharyngeal), X (vagus)
GVA cranial nerves (x3)
VII (facial), IX (glossopharyngeal), X (vagus)
GVE
general visceral efferent - autonomic, parasympathetic
GVE cranial nerves (x4)
III (oculomotor), VII (facial), IX (glossopharyngeal), X (vagus)
GSE
general somatic efferent - motor neurons
GSE cranial nerves (x4)
III (oculomotor), IV (trochlear), VI (abducens) – eye movement
XII (hypoglossal) – tongue
SVE
special visceral efferent - also motor neurons, but embryologically different (functionally identical to GSE)
SVE - cranial nerves (x5)
V (trigeminal), VII (facial), IX (glossopharyngeal), X (vagus), XI (accessory)
Olfactory nerve - nerve classification
SVA
Optic nerve - nerve classification
SSA
Oculomotor nerve - nerve classifications (x2)
- GSE: eye movement (adduction, elevation, depression, rotation), lifting eyelid
- GVE: ciliary muscle (near vision) and pupillary sphincter (constrict pupil)
Disorders:
Eye deviated down and out
Problem with CN III (oculomotor)
- down = unopposed action of superior oblique from CN IV
- out = unopposed action of latractus from CN VI
Disorders:
dilated pupil
Problem with CN III
due to unopposed action of sympathetic
Disorders:
Diplopia (double vision)
Problem with CN III
Trochlear nerve - nerve classification
GSE
Disorders:
Symptoms of damage to CN IV
- can’t look down while looking nasally
- head tilted, chin tucked toward contralateral side (to compensate for torsion on eye from lack of sup. oblique)
Trigeminal nerve - nerve classifications (x2)
- GSA: pain, temp, touch on face, in nasal and oral cavities, teeth, gums, cornea, and anterior 2/3 of tongue, and closing eyelid
- SVE - muscles of mastication and tensor tympani
Disorders:
Symptoms of damage to CN V (x4)
- weakness (in muscles of mastication)
- anesthesia (no sensation on face, etc.)
- loud noise (unable to dampen loud sounds)
- blink reflex decreased or abolished
Abducens nerve - nerve classification
GSE (lateral rectus muscle)
Disorders:
Symptoms of damage to CN VI
Eye is deviated ___
medially
Disorders:
Symptoms of damage to CN VI
pupil is ___
normal
Disorders:
Symptoms of damage to CN VI
diplopia [yes/no]
yes
Facial nerve - nerve classifications (x5)
- SVA: solitary nucleus -> solitary tract -> taste buds (anterier 2/3 of tonge)
- GSA: spinal nucl of V -> spinal tract of V -> outer ear touch, pain
- GVA: solitary nucleus -> solitary tract -> mechanoreceptors of nasopharynx
- GVE: lacrimal glands, submandibular gland, sublingual gland
- SVE: brachiomeric, muscles of facial expression and stapedius
Disorders:
Symptoms of damage to CN VII (x4)
- muscle weakness (in facial expression)
- dry eye
- lacking taste in anterior 2/3 of tongue
- blink (corneal) reflex abolished
vestibulocochlear nerve - nerve classification
SSA
glossopharyngeal nerve - nerve classifications (x5)
- SVA: taste buds on posterior 1/3 of tongue
- GSA: mechanosensation on outer ear and posterior 1/3 of tongue
- GVA: mechanoreceptors on pharynx, tonsis, palate, baroreceptors on carotid sinus, chemoreceptors on carotid body
- GVE: parasympathetic, carotid gland
- SVE: nucleus ambiguus -> stylopharyngeus muscle (involved in speech)
Disorders:
Symptoms of damage to CN IX (x3)
- reduced gag reflex
- no taste on posterior 1/3 of tongue
- no somatic sensation on posterior 1/3 of tongue, palate, tonsils, pharynx
vagus nerve - nerve classifications (x5)
- SVA: taste buds on epiglottis (wanes over lifetime)
- GSA: ear
- GVA: mechanoreceptors and nociceptors in larynx, thoracic and abdominal viscera, baroreceptors on aortic arch, chemoreceptors on aortic bodies
- GVE: thoracic and abdominal viscera, heart
- SVE: larynx (speech), pharynx, palate
Disorders:
Symptoms of damage to CN X (x5)
- weak, raspy voice
- can’t cough forcefully
- palate pulled toward intact side during ‘aah’
- reduced gag reflex
- dysphagia
spinal accessory nerve - nerve classification
SVE: trapezius and sternoclydomastoid
Disorders:
Symptoms of damage to CN XI
- absent/weak elevation of ipsilateral shoulder
- impaired rotation of chin away from injured side
hypoglossal nerve - nerve classification
GSE: nonbrachiomeric, tongue
Disorders:
Symptoms of damage to CN XII
- deviation of tongue toward damaged side
- fasciculation of tongue ‘bag full of worms’
- atrophy of tongue