D16 - Cranial nerve IX.

Question 1

IX

Name the cranial nerve IX

Answer 1

N. glossopharyngeus

Question 2

IX

What type of nerve?

Give the origin

Answer 2

• A mixed nerve, sensory and motor
• Motor fibers:
  
  • ​Originate in the rostral part of nucl. ambiguus of the medulla oblongata
• Parasympathetic fibers:
  
  • ​Arise from the nucl. parasympatheticus of n. glossopharyngeus
• Nuclei:
  
  1. ​Nucl. ambiguus
  2. ​​Nucl. tractus spinalis
  3. ​​Nucl. dorsalis n. vagi
  4. ​​Nucl. alare cinare laterale
  5. ​​Nucl. salivatorius caudalis
  6. ​​Nucl. tractus solitarii

Question 3

IX

Where does the nerve leave the skull?

Answer 3

For. jugulare

• Eq: for. lacerum aborale
  
  • ​Passes through gutteral pouch

Question 4

IX

Give the branches, innervation and draw the nerve

Answer 4

• It is a part of the vagus group, together with:
  
  • N. vagus (X)
  • N. accessorius (XI)
• Sensory to:
  
  • Middle ear
  • Caudal ¹/₃ of tongue
  • Pharynx (with n. vagus)
• Motor to:
  
  • Dilator of pharynx (m. stylopharyngeus caudalis)