D17 - Cranial nerve X.

Question 1

What is the name of cranial nerve X?

Answer 1

N. vagus

Question 2

Type of nerve

Answer 2

• Mixed nerve:
  
  • Motor fibers
  • Sensory fibers
  • Parasympathetic fibers

Question 3

Where does the nerve arise from?

Answer 3

• Motor fibers: arise in nucl. ambiguous of the medulla oblongata
• Sensory neurons: ggl. proximale of n. vagus
• Parasympathetic cell bodies: nucl. parasympatheticus of n. vagus

​Nucleus:

• Nucl. ambigus (somatomotor)
• Nucl. spinalis n. trigemini (somatosensory)
• Nucl. dorsalis n. vagi (visceromotor)
• Nucl. alae cinerae (viscerosensory)
• Nucl. tractus solitarii (special sensory)

Question 4

Where does the nerve leave the skull?

Answer 4

For. jugulare

(continues as the cranial part of n. vagus)

Question 5

Give the main divisions of the nerve

Answer 5

• Cranial part
• Cervical part
• Thoracic part
• Abdominal part

Question 6

Cranial part

1. Give the brancehs of the cranial part of n. vagus
2. Draw the cranial portion

Answer 6

1. R. auricularis (sensory)
2. R. pharyngeus (sensory)
3. R. laryngeus crnaialis
   
   1. ​External branch (motor)
   2. Internal branch (sensory)

Intracranial part:

• From ggl. jugulare
  
  • ​R. meningeus
  • R. communicans cum IX
  • R. auricularis

Extracranial part:

• From ggl. proximale:
  
  • ​Rr. pharyngei
    
    • ​Rr. dosalis
    • Rr. ventralis
  • N. laryngeus cranialis
• From ggl. distale:
  
  • ​R. internus
  • R. externus
  • N. depressor
  • N. laryngeus recurens
    
    • ​N. laryngeus caudalis

Question 7

Cervical part

Where does the cervical part of n. vagus begin?

Answer 7

• After detachment of n. larygeus cranialis, from ggl. cervicale craniale and continues to ggl. cervicale mediale
• Cervical part continues as a part of tr. vagosympatheticus
  
  • Runs with a. carotis communis

Question 8

Thoracic part

Give the branches and its pathway in the thoracic cavity

Answer 8

• The tr. vagosymatheticus splits at the thoracic inlet proximal to ggl. cervicale mediale
• N. vagus continues to mediastineun and gives off:
  
  • Rr. cardiaca to cardiac plexus
  • N. laryngeus caudalis (aka n. recurens)
    
    • Innervates laryngeal muscels (motor) and caudal larynx (sensory)
• The vagal trunk continues to the root of the lung, and divides into:
  
  • R. dorsalis
  • R. ventralis
• They unite with their counterparts from the opposit side of the esophagus to form the dorsal and ventral vagal trunk
• The dorsal and ventral vagal trunk pass through the hiatus esophageus of diaphragm → N. vagus abdominalis
• Plexus pericardius
• Plexus pulmonalis
• Plexus bronchalis
• Plexus esophageus​
• Along esophageus:
  
  • N. vagus dexter/sinister:
    
    • ​Tr. vagalis dorsalis
    • Tr. vagalis ventralis

Question 9

Abdominal part

Answer 9

• At the abdominal cavity it spreads out to join the sympathetic fibers in the formation of the neural plexus responsible for the innervation of the visceral organs
• Tr. vagalis dorsalis
  
  • ​Plexus coeliacus
  • Plexus mesentericus cranialis
• Tr. vagalis ventralis (innervate: parietal surface of stomach, liver, pylorus)​
• Ggl. soleare (ggl. coeliacus + ggl. mesentericum graniale)​

Question 10

Draw n. vagus through the body

Answer 10

Question 11

What do n. vagus innervate?

(ikke alt?)

Answer 11

• Skin of external ear (sensory from r. auricularis)
• Epiglottis, trachea, esophageus (sensory from r. pharyngeus)
• Caudal pharyngeus constrictors (motor, from external branch of n. laryngeus cranialis)
• Larynx (sensory from internal branch of n. laryngeus cranialis)
• Viscera of thoracic and abdominal cavities