8 CN IX, X, XI, XII Flashcards
CN XII (Hypoglossal)
- Axon:
- Origin:
- Peripheral termination:
- GSE
- Hypoglossal nucleus
- Tongue muscles
Tongue protrusion muscle
Genioglossus muscle
Hypoglossal nerve (LMN) lesion causes:
- Tongue deviation toward lesion
- Fasciculation
- Atrophy
UMN (Corticobulbar) injury of tongue causes:
- Tongue deviation toward side opposite UMN lesion
- No fasciculations
- Minimal atrophy
CN XI (Accessory)
- Axon
- CNS origin
- Peripheral termination
- SVE
- Accessory nucleus in cervical spinal cord (caudal medulla-C5)
- Sternocleidomastoid, trapezius
CN IX (Glossopharyngeal)
- Axon
- CNS origin/termination
- Peripheral origin/termination
- SSA
- Solitary tract nucleus
- Taste buds posterior 1/3 tongue
- GVA
- Solitary tract nucleus
- Carotid body and sinus
- GSA
- Spinal trigeminal nucleus
- Mucosa posterior 1/3 tongue, pharynx, middle ear, skin of outer ear
- GVE
- Inferior salivatory nucleus
- Parotid gland
- SVE
- Nucleus ambiguus
- Pharynx (stylopharyngeus)
Sudden burst of pain starts in posterior tongue or wall of pharynx, then radiates to ear. Trigger zone in this and attacks precipitated by swallowing/talking.
Glossopharyngeal Neuralgia
CN X (Vagus)
- Axon
- CNS origin/termination
- Peripheral origin/termination
- GSA
- Spinal trigeminal nucleus
- Skin of outer ear
- SVA
- Solitary tract nucleus
- Taste buds: epiglottis/esophagus
- GVA
- Solitary tract nucleus
- Thoracic/abdominal viscera; larynx/pharynx mucosa; aortic arch stretch receptors; aortic bodie chemoreceptors
- GVE
- Dorsal motor nucleus
- Thoracic/abdominal viscera: smooth muscle and glands
- SVE
- Nucleus ambiguus
- Larynx/pharynx
Gag reflex (touch one side of pharynx, elicit bilateral response):
Afferent component CN __
Efferent component CN __
IX
X
Tongue thrust reflex (infants-8 years possible)
Afferent limb CN ___
Efferent limb CN ___
V or IX
XII
The hypoglossal nucleus is located in this section of the brainstem:
Rostral medulla (medial posterior)
CN IX and X structures are also located on the Rostral Medulla