C12 - Cranial nerve V.

Question 1

Name the cranial nerve V.

Answer 1

N. trigemini

Question 2

Give the role of cranial nerve V.

Answer 2

• Mixed type:
  
  • Largest sensory nerve of the head
  • Motor nerve to:
    
    • Masticatory muscles
    • M. mylohyoideus
    • M. digastricus
    • Soft palate muscles

Question 3

Where are the nucleus of cranial nerve V. located?

Answer 3

• Trigeminal motor nucleus:
  
  • ​Metencephalon
• Trigeminal sensory nucleus:
  
  • ​Mesencephalon
  • Pons
  • Spine

Question 4

Give the main division of cranial nerve V. and their pathway out of the skull

Answer 4

• As the nerve leaves the ggl. trigemini it divides into three main branches:
  
  1. N. opthalmichi (V₁) → fissura orbitalis
  2. N. maxillaris (V₂) → for. rotundum
  3. N. mandibularis (V₃) → for. ovale

Question 5

V₁

Answer 5

• V₁ = N. opthalmichi
• Sensory innervation
• Runs in a common sheath with III, IV and VI cranial nerves → leaves the cranial cavity and enters the fissura orbitalis
• Branches:
  
  • N. frontalis (→ upper lid, nasal canthus, forehead)
    
    • ​N. supratrochlearis
    • N. supraorbitalis
    • N. sinum frontalium (nb eq?)
  • N. lacrimalis (→ lacrimal gland, temporal canthus)
    
    • ​Rr. glandulares
    • Rr. palpebralis
    • Ru: branches to horn
  • N. nasociliares
    
    • ​Nn. ciliares
    • N. infratrochlearis (→ conjuctiva, third eyelid)
    • N. ethmoidales (→ olfactory mucosa)

Question 6

V₂

Answer 6

• V₂ = N. maxillaris
• Sensory innervation​
• Sensory to:
  
  • Lower eyelid
  • Nasal mucosa
  • Upper teeth
  • Upper lid
  • Nose
• Branches:
  
  • N. meningeal ? (→ dura mater)
  • N. zygomaticus (→ skin of temporal and frontal regions)
    
    • ​N. zygomaticofacialis
    • N. zygomaticotemporalis
  • N. infraorbitalis (→ nose, muzzle, upper lid)
    
    • ​Rr. alveolaris
    • Rr. gingivales
    • Rr. dentales
    • Rr. labieles maxillares
    • Rr. nasalis externa
  • N. pterygopalatinus
    
    • ​N. nasalis caudalis (→ ventral nasal conchae, middle meatus)
    • N. palatina minor (→ soft palate)
    • N. palatina major (→ hard palate)

Question 7

V₃

Answer 7

• V₃ = N. mandibularis
• Sensory and mortor innervation
• Branches:
  
  • N. buccalis (→ cheek)
    
    • ​R. labialis maxillaris
    • R. labialis mandibularis
  • N. massetericus
    
    • ​N. massetericus (→ motor to m. masseter)
    • N. temporalis profunda (→ motor to m. temporalis)y
  • M. pterygoideus lateralis & medialis ( (→ motor to m. pterygoideus)
  • N. auriculotemporalis
    
    • ​R. auricularis rostralis (→ sensory to ear)
    • N. transversus faciei
    • R. communicans to n. auriculopalpebralis (VII)
    • R. temporalis (→ sensory tomeatus acousticus externa, gl. parotideus, cheeks)
  • N. alveolaris inferior
    
    • ​N. mylohyoideus (→ motor to m. mylohyoideus, m. digastricus)
    • Rr. alveolares
      
      • ​Caudales
      • Medialis
      • Rostrales
    • N. mentalis (→ sensory to lower lip and chin)
  • N. lingualis (→ sensory to tongue, gl. sublingualis, gl. mandibularis)
    
    • ​N. sublingualis