Cranial nerves Flashcards
CN III nuclei
Oculomotor (SM) and Edinger Westphal (GVM) nuclei
CN V nuclei
- Mesencephalic nucleus (GSS - proprioceptive)
- Pontine/chief sensory nucleus (GSS - epicritic)
- Spinal trigeminal tract nucleus (GSS - protopathic)
- Motor nucleus (SVM)
CN VII nuclei
- Facial nucl (BM)
- Sup. salivatory nucl (GVM)
- Solitary tract nucl (SVS)
- Spinal trigeminal nucl (GSS)
CN IX nuclei
- Ambiguus nucl (BM/SVM)
- Inf salivatory (GVM)
- Solitary tract nucl (SVS)
- Lat. ala cinerea nucl
- Spinal trigem. nucl
CN X nuclei
- Ambiguus nucl (BM/SVM)
- Dorsal nucl of vagus (GVM)
- Solitary tract nucl (SVS)
- Lat. ala cinerea (GVS)
- Spinal trigem. nucl (GSS)
CN XI nuclei
- Ambiguus nucl, caudal part (BM)
- Spinal accessory nucl (SM)
CN III pathway
Interpeduncular fossa > interpeduncular cistern > lat. border of cavernous sinus (btw ant. and post. petroclinoidal folds) > sup. orbital fissure > tendinous ring > sup. and inf. branches
Branches of III
Sup. division:
1) Levator palpebrae suprioris
2) Sup. rectur
Inf. division:
3) Inf. oblique
4) Med. rectur
5) Inf. rectus
GVM fibers of III (pathway)
From Edinger Westphal > ciliary ggl (synapse) > short ciliary nerves > ciliary muscles, circular m.
Edinger Westphal nucl innervation
Ciliary mm
Circular m
CN IV pathway
Midbrain > frenulum of sup. medullary velum (DORSALLY) > ambiens cistern > lat. wall of cavernous sinus (ant. petroclinoidal fold > sup. orbital fissure > sup. oblique m
IV innervation
Sup. oblique m on contralat. side (adduction, depression, internal rotation of eye)
CN VI pathway
Abducent nucl > pontomedullary junction > med. pontine cistern > freely in cavernous sinus via Dorello’s canal > sup. orbital fissure > lat. rectus m
CN VI innervation
Lat. rectus m (abduction)
CN V exits
Brain: btw pons and brachium pontis > lat. pontine/pontocerebellar cistern
Dural: Meckel’s cave
- V/1: cavernous sinus (lat. wall)
- V/2: cavernous sinus (lat. wall)
- V/3: foramen ovale
Scull:
- V/1: sup. orbital fissure
- V/2: for. rotundum
- V/3: for. ovale
Type of nerves in mesencephalic nucl
Pseudounipolar
Branches of V/1
Branches before exit of scull
1) Tentorial branch
2) Frontal n
- Med. supraorbital n
- Lat. supraorbital n
- Supratrochlear n
3) Lacrimal n
- Communicating branch w/ zygomatic n (GVM)
4) Nasociliary
- Infratrochlear n
- Ant. + post. ethmoidal nn
- Long ciliary nn
- Communicating branch (from eyeball through ciliary)
Origin of V/1
Gasserian/semilunar/trigeminal ggl in Meckel’s cave
V/2 pathway
Lat. wall of cavernous sinus > for. rotundum > pterygopalatine fossa (gives off zygomatic, infraorbital & pterygopalatine n) > inf. orbital fissure (gives off medial meningeal before entering)
Pes anserinus minor (location and branches)
Where infraorbital nerve penetrates infraorbital foramen (terminal branches)
- Inf. palpebral
- Ext. nasal
- Sup. labial
Type of fibers in V/2
PSY, SYM and SVA taste fibers
Branches of V/2
1) Medial meningeal ramus
2) Infraorbital n
- Post., middle and ant. alveolar branches
- Inf. palpebral
- Ext. nasal
- Sup. labial
3) Pterygopalatine n
- Post. sup. nasal nn
- Post. inf. nasal nn
- Greater palatine n
- Lesser palatine n
- Nasopalatine n (incisive canal)
4) Zygomatic n
- Communicating branch w/ lacrimal n (> lacrimal gland)
- Zygomaticofacial n
- Zygomaticotemporal n
Type of fibers in V/3
- GSS to trig. sensory nucl
- SVM to 1st pharyngeal arch
- SVS for taste
- GVM to glands of tongue, submandibular and sublingual glands
Branches of V/3
Before bifurcation:
1) Middle meningeal n
2) Tensor veli palatini nn
3) Med. pterygoid n
Anterior trunk:
4) Ant. + post. deep temporal nn
5) N to lat. pterygoid m
6) Masseteric n
7) Buccal n (afferent!)
Post trunk:
8) Auriculotemporal n (PSY fibers)
9) Lingual n
10) Inf. alveolar n
- Mylohyoid branch
- Dental b
- Incisive b
- Mental b
CN VII pathway
Btw pons and brachium pontis > fundus of int. acoustic meatus > facial canal > geniculate ggl (SVS fibers of solitary tract and GSS of spinal trigem. nucl synapse) > stylomastoid foramen
GVM fibers of VII (pathway)
Sup. salivatory nucl sends PSY fibers via:
- Greater petrosal n > pterygopalatine ggl (synapse > lacrimal n (V/1) > lacrimal gland
- Chorda tympani n (+ sensory fibers) travels in lingual n (V/3) > submandibular ggl > submand. and lingual glands
What is intermediate n?
SVS fibers from solitary tract nucl and PSY fibers from sup. salivatory
Geniculate ggl (location, synapses)
In facial canal, GSS fibers from spinal trigem. tract and SVS fibers from solitary tract synapse (CN VII)
Branches of VII
Intracranial branches:
1) Greater petrosal n
2) Sensory auricular br
3) Chorda tympani
4) Stapedial n
Extracranial branches (muscles):
5) Post. auricular n
6) Post. belly of digastric & stylohyoid mm
7) Parotid plexus
- Temporal br
- Zygomatic br
- Buccal br
- Marginal mandibular br
- Cervical br
CN VIII pathway (cochlear and vestibular)
Cochlear:
Spiral ggl > int. aucustic meatus > btw pons and brachium pontis > cochleat nucl > trapezoid body/medullary striae > lat. lemniscus
Vestibular:
Vestibular ggl > int. aucustic meatus > btw pons and brachium pontis > vestibular nucl > ascending and descending branches > cerebellum (inf. peduncle)
CN IX pathway
Medulla > lat. paraolivary sulcus > jugular foramen (ant. pars nervosa) > stylopharyngeus m (lower border, curves forward) > palatine tonsil, mucous memb. of fauces, base of tongue and serous glands of mouth
Branches of IX
1) Tympanic n of Jacobsen > lesser petrosal n (GVM/GSS)
2) Communicating br w/ auricular/Arnold’s n (GSS)
3) Pharyngeal plexus
- Stylopharyngeus + sup. and upper 1/2 of middle constrictors (BM)
- Tonsillar br (GSS)
- Lingual br (SVS,GSS)
- Pharyngeal br (GSS, BM)
4) Carotid sinus n
Pharyngeal plexus receives fibers from which CNs?
Glossopharyngeal n
Vagus n
Accessory n
GVM fibers from IX (pathway)
Inf. salivatory nucl > jugular foramen > tympanic n of Jacobsen > lesser petrosal n > foramen ovale > otic ggl > parotid gland
CN X branches
1) Meningeal br
2) Auricular br (Arnold’s)
3) Pharyngeal branches
4) Sup. laryngeal n
- Internal laryngeal n
- Ext. laryngeal n
5) Recurrent laryngeal n
- Tracheal branches
- Esophageal branhes
- Inf. laryngeal n
6) Cardiac branches
- Sup. + inf. cervical cardiac br
- Thoracic cardiac br
7) Esophageal branches
8) Pulmonary branches
9) Ant. + post. vagal trunks
- Gastric
- Celiac
- Hepatic
- Vagal branches
CN XI pathway
Ambiguus and accessory nucl
> cranial root: inf. in lat. paraolivary nucl > lat. in post. cranial fossa OR
> spinal root: spinal segments C1-6 > foramen magnum
> jugular foramen, ant. pars nervosa (both roots) > int. (cranial) and ext. (spinal) branches
Branches of XI
1) Internal branch (cranial root)
- Recurrent laryngeal n
- Pharyngeal br
2) External branch (spinal)
- Sternocleidomastoid and trapezius mm
CN XII pathway
Hypoglossal nucl > med. paraolivary sulcus > hypoglossal canal (spirals behind vagus, passing deep to post. belly of digastric > loop of hypoglossal n)
Branches of XII
Branch to intrinsic mm of tongue:
- sup. + inf. longitudinal m
- verticalis m
- transversus m
Branch to extrinsic mm:
- genioglossus m
- hyoglossus m
- styloglossus m
Spinal trigeminal tract nucleus receives fibers from which CNs?
V, VII, IX and X
