glossopharyngeal nerve (CN IX)

Introduction

Somatic & visceral motor; somatic & visceral sensory.

Afferents

Nucleus solitarius

• located in the posterior rostral medulla lateral to the inferior salivary nucleus
• visceral sensory
• CN 9 fibers synapsing in the nucleus solitarius innervate:
  • posterior 1/3 of tongue - taste
  • carotid body
  • carotid sinus
• nucleus solitarius is shared by CN 7, CN 9, CN 10

Spinal nucleus of CN 5

• the sensory nucleus of CN 5 actually obtains sensory input from CN 7, 9, & 10, but because of the dominant input from CN 5, retains it name
• CN 9 fibers synapsing in the spinal nucleus of CN 5 innervate:
  • external ear
  • posterior 1/3 of tongue

Efferents

Nucleus ambiguous

• located in the rostral medulla anterior to the nucleus solitarius
• CN 9 fibers originating in the nucleus ambiguous innervates the stylopharyngeus - swallowing
• the nucleus ambiguous is shared by CN 9 & CN 10

Inferior salivary nucleus

• located in the posterior rostral medulla medial to the nucleus solitarius
• CN 9 fibers originating in the inferior salivary nucleus innervates the parotid gland with relay in the otic ganglion

Course

• exits from the cranium through the jugular foramen

More general terms

• cranial nerve

Additional terms

• carotid body
• carotid sinus; carotid bulb
• glossopharyngeal neuralgia
• inferior salivary nucleus
• jugular foramen
• nucleus ambiguous
• nucleus solitarius
• spinal (caudal) trigeminal nucleus