CN VIII-XII Flashcards Preview

Gross Anatomy > CN VIII-XII > Flashcards

Flashcards in CN VIII-XII Deck (9)
Loading flashcards...
1
Q

CN VIII

A

Vestibulocochlear n. (composed of vestibular n. and cochlear n.)

Originates in membranous labyrinth of inner ear in petrous temporal bone; leaves petrous temporal bone via internal acoustic meatus along with facial n.

2
Q

Vestibular n.

A

Part of CN VIII

Transmits afferent impulses to brain relating to pull of gravity and linear/angular acceleration
Receptors (cristae and maculae) in semicircular ducts transmit impulses to vestibular ganglion -> travel along vestibular portion of CN VIII to CNS

Dysfunction - disequilibrium, circling, head tilt of affected side, nystagmus of unaffected side
Tests - Observe gait (should be done blindfolded); righting reflexes

3
Q

Cochlear n.

A

Part of CN VIII

Responsible for hearing (SSA)
Receptors in spiral organ (Organ of Corti) within cochlea transmit impulses to spiral ganglion -> travel along cochlear portion of CN VIII to CNS

Dysfunction - deafness
Tests - Clap hands or whistle
Genetic deafness in blue-eyed, white cats and dalmatians

4
Q

CN IX

A

Glossopharyngeal n.

Sensory - caudal portion of tongue, pharyngeal mucosa, carotid sinus (GVA); taste from caudal 1/3 of tongue (SVA)

Motor - stylopharyngeus and other pharyngeal mm. (along w/ CN X) (GSE)

Parasympathetic - to parotid and zygomatic salivary glands (GVE)

5
Q

Sensory of CN IX

A

Sensory from baroreceptors in wall of carotid sinus and chemoreceptors in carotid body
Sensory from pharyngeal mucosa via pharyngeal br.
Sensory for touch, pain, thermal from caudal 1/3 of tongue via lingual br. (GVA)
Sensory for taste from caudal 1/3 of tongue (SVA)

Dysfunction - hypo/hypertension to head; brady/tachycardia
Test - carotid sinus reflex; inc. pressure on carotid sinus will result in a dec. heart rate (artificially inc. pressure on baroreceptors)

6
Q

Motor of CN IX

A

Motor to pharyngeal mm. via pharyngeal br. (GSE)

Dysfunction - difficulty swallowing (dysphagia)
Tests - swallowing reflex and gag reflex

7
Q

Pharyngeal plexus

A

Junction of pharyngeal br. of CN IX and pharyngeal br. of CN X

Supplies motor innervation to pharyngeal mm. and sensory innervation to pharyngeal mucosa

Contains postganglionic sympathetic fibers from cranial cervical ganglion

8
Q

Parasympathetic of CN IX

A

Innervation of the parotid and zygomatic salivary glands

Dysfunction - partial dryness of mouth

9
Q

CN X

A

Vagus n.

Sensory - pharynx, larynx, trachea, esophagus, thoracic and abdominal viscera (GVA); external ear canal (GSA); taste to base of tongue and pharynx (SVA)

Motor - muscles of pharynx, larynx, esophagus (GSE)

Parasympathetic - cervical, thoracic, and abdominal viscera