The trigeminal nerve Flashcards
What are the two umbrella classifications of nerve fibres?
- Sensory
- Motor
What are the two types of motor fibre transmission?
- to involuntary muscles (heart)
- to voluntary muscles (mastication)
What is cranial nerve V?
The trigeminal nerve
what is the largest and most important cranial nerve?
The trigeminal nerve
What types of fibres does the trigeminal nerve have?
Both sensory and motor
What is the principal general sensory nerve for the head?
The trigeminal nerve
What are the three divisions of the trigeminal nerve?
- Ophthalmic
- Maxillary
- Mandibular
What is the smallest division of the trigeminal nerve?
The ophthalmic nerve
Describe the opthalmic nerve.
- mostly sensory
- leaves trigeminal ganglion and enters orbit through the superior orbital fissure
- has three additional divisions (frontal, lacrimal, nasociliary)
What is the second division of the trigeminal nerve?
The maxillary nerve
What does the maxillary nerve supply?
- Mostly sensory
- maxilla & skin, maxillary sinuses, nasal cavity, palate, nasopharynx, dura mater
Where does the maxillary nerve exit the skull?
The foramen rotundum in the sphenoid bone
What joins up with the maxillary nerve as it enters the trigeminal ganglion?
The meningeal branches from the dura mater
What are the five sub-branches of the maxillary nerve?
- zygomatic nerve (primarily sensory)
- infraorbital nerve (sensory)
- nasopalatine nerve (sensory)
- greater palatine (sensory)
- lesser palatine (sensory)
What does the nasopalatine nerve supply?
- anterior hard palate
- maxillary anterior teeth
- tissues of the nasal septum
(all sensory)
Describe the greater palatine nerve.
- Sensory nerve for
- posterior hard palate
- posterior lingual gingiva
Describe the lesser palatine nerve.
- Sensory nerve for
- soft palate and palatine tonsils
What are the dental branches of the maxillary nerve?
- Anterior superior alveolar
- Middle superior alveolar
- Posterior superior alveolar
What does the ASA nerve supply?
- maxillary anterior teeth
- facial gingiva
What does the MSA nerve supply?
- upper premolars
- Mesiobuccal root of upper 1st molar (important)
- sinus mucosa
- buccal gingiva
What does the PSA supply?
- upper molars (2nd and 3rd)
- maxillary sinuses
What is the largest division of the trigeminal nerve?
The mandibular nerve
What is the mandibular nerve composed of?
- Large sensory root
- Small motor root
What is the anterior trunk of the mandibular nerve composed of?
- Long buccal nerve
- Muscular branches
What is the posterior trunk of the mandibular nerve composed of?
- Auriculotemporal nerve
- Inferior alveolar nerve
- Lingual nerve
(P-AIL)
Describe the buccal (mandibular) nerve
and where is it located
Sensory
- Supplies buccal mucosa, skin of cheek, buccal gingiva
- located on buccinator but doesnt innervate
What are the muscular branches of the mandibular nerve?
All motor:
- Masseteric nerve
- Lateral pterygoid nerve
- Deep temporal nerve
mld (me lady)
Describe the auriculotemporal (mandibular) nerve
and fibres it carries
Sensory nerve for external ear, skin of scalp, tmj
- Carries postganglionic parasympathetic fibres to the parotid gland
Describe the lingual nerve
Sensory nerve for general sensation of body of tongue (ant. 2/3), floor of mouth, lingual gingiva.
Describe the mylohyoid (mandibular) nerve.
Motor nerve
- to mylohyoid muscle and anterior belly of the digastric muscle
Describe the mental (mandibular) nerve.
innervation, path
Sensory nerve for the chin, lower lip, labial mucosa of anterior teeth.
Enters through mental foramen.
Describe the incisive (mandibular) nerve.
Sensory nerve for mandibular premolars and anterior teeth.
What does the incisive nerve merge with?
and where?
The mental nerve to form the IA in the mandibular canal
Describe the inferior alveolar nerve.
innervation, what forms it
Sensory nerve for mandibular molars
- Formed by mental and incisive nerves
What is a trigeminal nerve disorder?
Trigeminal neuralgia
What is trigeminal neuralgia?
Nerve pain due to compression or inflammation or degeneration of the trigeminal nerve
Where does trigeminal neuralgia occur?
The right side of the head, affects CV2 and 3 more than CV1
What are treatments of trigeminal neuralgia? (6)
- Anticonvulsants (carbamazepine)
- Botox
- Laser surgery
- Surgical neurectomy
- Radiation therapy
- Alcohol injections
What does the deep temporal branch of the mandibular nerve innervate?
and what does it pass through
The temporalis muscle
passes through the sphenoid bone
What does the masseteric branch of the mandibular nerve innervate?
and what does it pass through
The masseter muscle
passes through the mandibular notch
What does the lateral pterygoid branch of the mandibular nerve innervate?
Both heads of the lateral pterygoid muscle.
