Cranial Nerve 5

Question 1

CN5

Answer 1

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)

Question 2

Emerges from brainstem..

Answer 2

and courses anteriorly to reach MIDDLE CRANIAL FOSSA

Question 3

Trigeminal ganglion

Answer 3

Located in Trigeminal impression/cave (Meckel’s cave)

From ganglion, emerge V1, V2, V3

Question 4

V1

Answer 4

passes lateral wall of cavernous sinus to reach superior orbital fissure

Question 5

V2

Answer 5

passes lateral wall of cavernous sinus to reach foramen rotundum

Question 6

V3

Answer 6

inferior course to reach foramen ovale

Question 7

Branches of Ophthalmic N (V1)

Answer 7

1. Meningeal branch
2. Lacrimal n
3. Frontal n
   - Supraorbital n
   - Supratrochlear n
4. 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

Question 8

Meningeal branch

Answer 8

aka tentorial nerve

sensory branch, emerges from V1 before it traverses superior orbital fissure

Question 9

Lacrimal, frontal and nasociliary nerves

Answer 9

Before opthamlamic n traverses superior orbital fissure to enter orbit, gives off these branches

Question 10

Lacrimal n

Answer 10

Travels along lateral border of orbit to reach lacrimal gland and lateral eye

Question 11

Frontal n

Answer 11

Within orbit, frontal branches into supraorbital and supratrochlear n (course anteriorly through orbit to emerge superior to eye)

Question 12

Nasociliary n

Answer 12

Travels in plane deep to lacrimal and frontal nerves

Branches:

1. Sensory root –> ciliary ganglion-> short ciliary nerves
2. Long ciliary nerves
3. Posterior ethmoidal n (exits orbit via posterior ethmoidal foramen)
4. Anterior ethmoidal n (exits orbit via anterior ethmoidal foramen)
   - -gives rise to internal/external nasal branches
5. Infratrochlear n

Question 13

Branches of Maxillary Nerve (V2)

Answer 13

1. Meningeal branch before traversing foramen rotundum
   Branches in PPF
2. Zygomatic n (zygomaticotemporal n, zygomaticofacial n)
3. 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
4. Posterior superior alveolar n
5. Infraorbital n (continuation of maxillary n)
   -Middle superior alveolar n
   -Anterior superior alveolar n
   -Terminal branches (palpebral, nasal, superior labial)

Question 14

Meningeal branch

Answer 14

In middle cranial fossa, before V2 courses foramen rotundum to enter PPF

Question 15

Zygomatic nerve

Answer 15

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

Question 16

Communicating roots to PPG (pterygopalatine nerves)

Answer 16

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

Question 17

Orbital branches

Answer 17

traverse inferior orbital fissure to reach orbit

Question 18

Medial posterior superior nasal, lateral posterior superior nasal and nasopalatine nerves

Answer 18

Traverse sphenopalatine formane to enter nasal cavity

Question 19

Pharyngeal n

Answer 19

Travels in palatovaginal canal to reach nasopharynx

Question 20

Greater palatine and lesser palatine nerves

Answer 20

descend in greater palatine canal to reach palate

Question 21

Nerve of pterygoid canal (includes GVE and SA fibers from CN-7)

Answer 21

course pterygoid canal to reach PPG

Question 22

Posterior superior alveolar n

Answer 22

Leaves PPF through pterygomaxillary fissure and enters maxilla via alveolar foramen

Question 23

Infraorbital nerve

Answer 23

Name change occurs as V2 traverses inferior orbital fissure. Courses in infraorbital groove and canal before emerging on face via infraorbital foramen

Question 24

lnfraorbital n gives rise to

Answer 24

Middle superior alveolar n
Anterior superior alveolar n

Infraorbital n terminates as palpebral, nasal and labial branches

Question 25

Superior Dental Plexus

Answer 25

Formed by nerves that carry sensory info from maxillary teeth and adjacent gingival tissue

Question 26

Structures of superior dental plexus

Answer 26

- 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)

Question 27

Innervation of Tooth via Dental

Answer 27

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

Question 28

Branches of Mandibular Nerve (V3)

Answer 28

``` 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) ```

Question 29

Nervus spinosus

Answer 29

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

Question 30

Nerve to medial pterygoid

Answer 30

motor (SVE) and proprioceptive (GSA) to medial pterygoid muscle; sends small branches to tensor tympani muscle and tensor veil palatine muscle