Cranial Nerve 5 Flashcards
CN5
emerges from brainstem as large sensory (GSA) root and small motor (SVE) root
Resident fibers: GSA, SVE *muscles of first pharyngeal arch
Acquired: SA, GVE (parasympathetic fibers to SM and glands)
Emerges from brainstem..
and courses anteriorly to reach MIDDLE CRANIAL FOSSA
Trigeminal ganglion
Located in Trigeminal impression/cave (Meckel’s cave)
From ganglion, emerge V1, V2, V3
V1
passes lateral wall of cavernous sinus to reach superior orbital fissure
V2
passes lateral wall of cavernous sinus to reach foramen rotundum
V3
inferior course to reach foramen ovale
Branches of Ophthalmic N (V1)
- Meningeal branch
- Lacrimal n
- Frontal n
- Supraorbital n
- Supratrochlear n - Nasociliary n
- Sensory root to ciliary ganglion–> short ciliary n
- Long ciliary n
- Posterior ethmoidal n
- Anterior ethmoidal n-> internal and external nasal branches
- Infratrochlear n
Meningeal branch
aka tentorial nerve
sensory branch, emerges from V1 before it traverses superior orbital fissure
Lacrimal, frontal and nasociliary nerves
Before opthamlamic n traverses superior orbital fissure to enter orbit, gives off these branches
Lacrimal n
Travels along lateral border of orbit to reach lacrimal gland and lateral eye
Frontal n
Within orbit, frontal branches into supraorbital and supratrochlear n (course anteriorly through orbit to emerge superior to eye)
Nasociliary n
Travels in plane deep to lacrimal and frontal nerves
Branches:
- Sensory root –> ciliary ganglion-> short ciliary nerves
- Long ciliary nerves
- Posterior ethmoidal n (exits orbit via posterior ethmoidal foramen)
- Anterior ethmoidal n (exits orbit via anterior ethmoidal foramen)
- -gives rise to internal/external nasal branches - Infratrochlear n
Branches of Maxillary Nerve (V2)
- Meningeal branch before traversing foramen rotundum
Branches in PPF - Zygomatic n (zygomaticotemporal n, zygomaticofacial n)
- Communicating branches (2) with pterygopalatine ganglion
– orbital, medial and lateral posterior superior nasal, has-palatine, greater palatine [greater palatine gives off lateral posterior inferior nasal n], lesser palatine, pharyngeal)
-Nerve of pterygoid canal carries fibers from CN7–> PPG - Posterior superior alveolar n
- Infraorbital n (continuation of maxillary n)
-Middle superior alveolar n
-Anterior superior alveolar n
-Terminal branches (palpebral, nasal, superior labial)
Meningeal branch
In middle cranial fossa, before V2 courses foramen rotundum to enter PPF
Zygomatic nerve
In PPF, enters orbit via INFERIOR ORBITAL FISSURE –> zygomaticofacial and zygomaticoptermporal nerves, LEAVE orbit and emerge on face via same named foramina.
note: communicating branch from zygomaticotemporal n to lacrimal n
Communicating roots to PPG (pterygopalatine nerves)
PPG suspended from V2 via 2 communicating branches (primary GSA fibers) GSA fibers pass through PPG, without interruption and into following branches: 1. orbital branches 2. medial posterior superior nasal n 3. lateral posterior superior nasal n 4. nasopalatine n 5. greater palatine n 6. lesser palatine n 7. pharyngeal n
- Posterior superior alveolar n
- Infraorbital n
Orbital branches
traverse inferior orbital fissure to reach orbit
Medial posterior superior nasal, lateral posterior superior nasal and nasopalatine nerves
Traverse sphenopalatine formane to enter nasal cavity
Pharyngeal n
Travels in palatovaginal canal to reach nasopharynx
Greater palatine and lesser palatine nerves
descend in greater palatine canal to reach palate
Nerve of pterygoid canal (includes GVE and SA fibers from CN-7)
course pterygoid canal to reach PPG
Posterior superior alveolar n
Leaves PPF through pterygomaxillary fissure and enters maxilla via alveolar foramen
Infraorbital nerve
Name change occurs as V2 traverses inferior orbital fissure. Courses in infraorbital groove and canal before emerging on face via infraorbital foramen
lnfraorbital n gives rise to
Middle superior alveolar n
Anterior superior alveolar n
Infraorbital n terminates as palpebral, nasal and labial branches
Superior Dental Plexus
Formed by nerves that carry sensory info from maxillary teeth and adjacent gingival tissue
Structures of superior dental plexus
- Posterior superior alveolar n (branch off maxillary n)
- Middle superior alveolar n (branch off infraorbital n)
- inconsistent, when absent, territory supplied by anterior superior alveolar n (or posterior superior alveolar n)
- Anterior superior alveolar n (branch off infraorbital n)
Innervation of Tooth via Dental
Dental pulp innervated by A-delta and C-fibers from CN-V (GSA) + postganglionic sympathetic nerve fibers from superior cervical ganglion (GVE).
- A delta and C fibers enter root canal along with Bfs and ramify as a plexus. Nerve fibers may continue into odontoblast layer and enter dentinal tubules
- GVA fibers in pulp that provide CNS with info regarding vascular tone
Branches of Mandibular Nerve (V3)
Immediate Branches -Meningeal branch -N to medial pterygoid Anterior Division -N to lateral pterygoid -Deep temporal nerves (anterior and posterior) -Masseteric n -Long buccal n Posterior Division -Auriculotemporal n -Lingual n (receives chorda tympani n from CN7) -Inferior alveolar n (gives off n to mylohyoid, terminates as mental nerve and incisive n)
Nervus spinosus
Recurrent meningeal branch, re-enters cranial cavity via foramen spinosum (travels with middle meningeal a) and carries GSA from meninges of anterior and middle cranial fossae
Nerve to medial pterygoid
motor (SVE) and proprioceptive (GSA) to medial pterygoid muscle; sends small branches to tensor tympani muscle and tensor veil palatine muscle
