L27, 28 - Nerves of head and neck Flashcards
List all the parasympathetic ganglia of Head and neck?
Ciliary
Pterygopalatine
Submandibular
Otic
List all the special sensory ganglia of head and neck?
Vestibular
Spiral
Geniculate
Inferior vagal (nodose ganglion)
Inferior glossopharyngeal* mixed general and special sensory)
List all the general sensory ganglia of the head and neck?
Neck: T2-T5 Dorsal root ganglia
Head:
Superior vagal (Jugular ganglion)
Superior glossopharyngeal
Trigeminal
Inferior glossopharyngeal* mixed general and special sensory
List all the sympathetic ganglia of Head and neck?
Superior, Middle, Inferior cervical sympathetic ganglia
Describe the tract of somatic motor neuron from spinal cord.
Anterior horn of spinal cord >> ventral root >> Spinal nerve
>> exit via dorsal and ventral ramus to skeletal muscles of body
Describe the tract of visceral* motor neuron from spinal cord.
Lateral horn of spinal cord
>> ventral root >> spinal nerve >> White ramus to sympathetic ganglion/ paravertebral ganglion: 3 exits:
1) PreGN fiber >> white rami communicantes >> synapse at sympathetic ganglia of another vertebral level >> PostGN fiber exit via grey rami communicantes >> spinal nerve
2) PreGN >> white rami communicantes >> synapse at sympathetic ganglion of same level >> grey rami communicantes to spinal nerve >> exit via sympathetic nerve
3) PreGN synapse at ganglion >> PostGN exit via sympathetic splanchnic nerve to prevertebral ganglia
List the anterior and posterior branches of the cervical plexus?
C2-C5 spinal nerves form cervical plexus
Posterior branches
C2 = Greater + Lesser occipital n.
C3 = Third occipital n.
Anterior branches
- Superior and Inferior roots of Ansa Cervicalis
- Great Auricular nerve (C2,C3)
- Transverse Cervical nerve (C2,C3)
- Supraclavicular nerve (C3,C4)
- Phrenic nerve
Describe the cutaneous distribution of spinal nerves at the head and neck**?
Dorsal ramus of spinal nerve C2-C5 supply skin behind vertex:
Great occipital (C2),
Lesser occipital (C2),
Third occipital (C3),
Branch from C4, Branch from C5
Ventral ramus of spinal nerves C2-C5 mix in plexus: cutaneous regions anterior to vertex supplied by mixed spinal nerves:
Great auricular (C2, C3),
Transverse cervical (C2, C3),
Supraclavicular (C3,C4) with Medial, Intermediate, Lateral branches
List the cranial nerves with only sensory function
⎼ Olfactory (I)
⎼ Optic (II)
⎼ Vestibulocochlear (VIII)
List the cranial nerves with only motor function?
⎼ Oculomotor (III)
⎼ Trochlear (IV)
⎼ Abducent (VI)
⎼ Accessory (XI)
⎼ Hypoglossal (XII)
List the cranial nerves with mixed motor and sensory functions?
⎼ Trigeminal (V)
⎼ Facial (VII)
⎼ Glossopharyngeal (IX)
⎼ Vagus (X)
List all the effectors of the sympathetic system in head and neck?
Smooth muscles:
Dilator pupillae
Superior tarsal muscle
Erector pili muscle
Blood vessel wall muscles
Sweat glands
Define the arteries associated with the superior, middle and inferior cervical ganglia?
Superior (C1-C4) = Common, external and internal carotid arteries
Middle (C5,C6)= Inferior thyroid artery
Inferior (C7,C8) = Vertebral and subclavian arteries
Describe how sympathetic chain from T1-L2 can reach structures in the head and neck?
T1- L2 Intermediolateral (IML) cell columns at the Lateral horn of spinal cord
>> ventral root >> spinal nerve >> white ramus communicantes
>> PreGN fiber travel up to superior cervical ganglia and synapse
>> gray ramus communicantes >> PostGN fiber reach organs/ effectors in head
Describe the distribution of nerves from the superior cervical ganglion to various plexues? (3)
From Superior cervical ganglion: Post-GN fibers:
1) Internal carotid nerve plexus >> Tarsal muscle, pupillary dilator, ciliary body, cerebral vessels, Lacrimal gland
2) External carotid nerve plexus >> nasal gland, salivary glands
3) Gray rami communicantes >> skin vessels, sweat glands, arrectores pili muscle
Tract the sympathetic innervation of the lacrimal gland blood vessels
Superior cervical ganglion
>> internal carotid plexus
>> Deep petrosal nerve
>> Vidian nerve >> Pterygopalatine ganglion
>> Maxillary nerve >> Zygomatic nerve
>> Lacrimal nerve
>> Lacrimal gland blood vessels
>> Vasocontriction = reduce tear outflow
Tract the innervation pathway of superior tarsal muscle?
Superior cervical ganglion
>> Internal carotid plexus
>> Oculomotor nerve (superior division)
>> superior tarsal muscle = Widening of palpebral fissure
Tract the innervation of the iris dilator and Choroidal, conjunctival blood vessels?
Superior cervical ganglion
>> Internal carotid plexus
>> Opthalmic division
>> Nasociliary nerve:
1) Long ciliary nerve >> iris dilator = Mydriasis
2) Sympathetic root >> ciliary ganglion >> short ciliary nerve >> choroidal and conjunctival BV vasocontriction
Tract the sympathetic innervation fo salivary glands?
T1,T2 sympathetic chain
>> superior cervical ganglion
>> External cartoid plexus >> tract along Lingual/ facial artery
>> direct to submandibular and sublingual glands (change bloodflow, not secretion)
List the parasympathetic effectors of the head and neck?
From brainstem nuclei to Submandibular, Otic, Ciliary and Pterygopalatine ganglia:
Smooth muscles:
- Ciliary muscles
- Pupillary sphincter
Glandular tissue:
- Salivary gland
- Lacrimal gland
- Nasal and palatine mucosa
Which cranial nerves form the parasympathetic supply of the head and neck?
oculomotor nerve [III]
Facial nerve [VII]
glossopharyngeal nerve [IX]
branches of the trigeminal nerve [V].
Tract the parasympathetic innervation of ocular muscles? (ciliary and iris)
Edinger westphal nucleus
>> CN III Inferior division
>> Ciliary ganglion
>> Short ciliary nerve
>> Iris sphincter and Ciliary muscle
Miosis and Accomodation
Tract the parasympathetic supply of the lacrimal gland?
Lacrimal nucleus in pons
>> Facial nerve
>> Greater petrosal nerve
>> Vidian nerve
>> Pterygopalatine ganglion
>> Maxillary nerve
>> Zygomatic nerve
>> Lacrimal nerve
>> Lacrimal gland
Tract the autonomic innervation of the parotid gland?
Inferior salivatory nucleus
>> CNIX through jugular foramen
>> Tympanic nerve/ tympanic plexus
>> Through foramen ovale and mandibular nerve
>> Otic ganglion
>> Auriculotemporal nerve
>> Parotid gland
Define the cranial exit points of CN I, II, III, IV, VI?
CNI = Cribiform plate
CNII = Optic foramen
CNIII, IV, VI = Superior orbital fissure
CN IV = Superior orbital fissure
Define the cranial exits of CNV?
V1 = Superior orbital fissure
V2 = Foramen Rotundum
V3 = Foramen ovale
Define the cranial exits of CNVII, VIII, IX, X, XI, XII
CN VII = entry at internal acoustic meatus, exit at stylomastoid foramen
CN VIII = Internal acoustic meatus
CN IX,X,XI = Jugular foramen
CN XII = Hypoglossal foramen
Nerve supply of the pharynx.
Name the exception.
Pharyngeal plexus = CN 9,10 + sympathetic
Stylopharyngeus = CN 9
Nerve supply of Palate.
Name exception
Pharyngeal plexus (CN 9,10, sympathetic)
Exception= Tensor veli palatini = Nerve to medial pterygoid (CN 5)
Nerve supply of tongue
Name exception
Hypoglossal nerve CN12
Palatoglossus = Pharyngeal plexus (CN9,10,sympathetic)
Nerve for facial expression and buccinator muscle.
Exception?
Facial nerve
Levator palpebrae superioris = CN3
Nerve supply for Muscles of mastication
Exception?
V3
Buccinator = CN7
Nerve supply fo Larynx
Exception?
Recurrent laryngeal nerve
Cricothyroid = External branch of Superior laryngeal nerve (CN 10)
