Cranial Nerves and Autonomics (Wright) Flashcards
What are the somatic motor nerves?
III Oculomotor: all extraocular eye muscles (except superior oblique and lateral rectus)
IV Trochlear: superior oblique
VI Abducens: lateral rectus
XII Hypoglossal: intrinsic and extrinsic tongue muscles except palatoglossus
What are the branchial motor nerves?
V Masticator: muscles of mastication
VII Facial: muscles of facial expression
IX, X Ambiguus: muscles of pharynx and larynx
XI Accessory: trapezius and sternomastoid
“5, 7, 9, 10, 11”
What are the visceral motor (parasympathetic) nerves?
III Edinger-Westphal: ciliary muscle, constrictor pupillae
VII Superior Salivatory: all glands of the head except the integ. and paratid
IX Inferior Salivatory: parotid gland
X Dorsal Vagus: all thoracic viscera and abdominal viscera to the splenic flexure
What are the visceral sensory nerves?
IX, X solitarius: visceral afferent info necessary for visceral reflexes, nausea, NOT pain
What are the general sensory nerves?
V, VII, IX, X trigeminal: pain, temp, touch, proprioception from head, neck, sinuses, meninges
What are the special sensory nerves?
I olfactory bulb: smell
II retina: vision
VII, IX gustatory : taste
VIII vestibular : balance
VIII cochlear: hearing
Derivatives of the first (mandibular) pharyngeal arch
N: trigeminal nerve
M: mastication, mylohyoid and anterior belly of diagastric, tensor tympani, tensor veli palatini
B: malleus and incus
L: anterior L. of malleus, sphenomandibular L.
Derivatives of the second (hyoid) arch?
N: Facial N.
M: muscles of expression, sapedius, stylohoid, posterior belly of digastric
B: stapes, styloid process, lesser cornu of hyoid, upper part of hyoid
L: stylohyoid L.
Derivatives of the third pharyngeal arch?
N: Glossopharyngeal
M: stylopharyngeus
B: greater cornu of hyoid, lower part of hyoid
Derivatives of the fourth and sixth pharyngeal arch?
N: Superior laryngeal branch of vagus, recurrent laryngeal branch of vagus
M: cricothyroid, levator veli palatini, constrictors of pharynx, instrinsic M. of larynx, striated muscles of esophagus
B: thyroid, cricoid, arytenoid, corniculate, cuneiform cartilages
“nerves and muscles of larynx, pharynx muscles, striated esophagus muscles, all the thyroid/pharyngeal cartilages)
General Rules concerning Autonomics of the Head
all sympathetic fibers are postsynaptic and rise off the superior cericval ganglion of the sympathetic trunk
they travel on vessels to the structures that they innervate (deep petorsal nerve)
presynaptic parasymapthetics come off the nuclei in the brain stem and synapse in the head (ciliary, pterygopalatine, otic and submandibualr ganglions)
all postsynaptic fibers “piggy back” on a branch of the trigeminal N. to arrive at the structure they innervate
Olfactory N
- CN I
- smell to brain, only type to regenerate
- originates in the bipolar neurons in olfactory mucosa of nasal cavity
- trabels through cribiform plate of ethmoid and synsapses in olfactory bulbs, in anterior cranial fossa
- Anosmia (loss of smell)
Optic N.
- vision to brain
- originates in retina
- enters cranium via optic foramen of sphenoid bone, uniting at optic chiasm. Optic tracts travel to lateral genicualate nucleus of thalamus, forwarding info to occipical lobe
- Anopsia (visual deficit)
Olfactory nerve component is?
special sensory
sensation of smell
the optic nerve component is?
special sensory
conveys visual info from retina
oculomotor component?
general somatic efferent: supplies levaotr palpebrae superioris, superior rectus, medial rectus, inferior recuts, inferior oblique muscle of the eye
general visceral efferent: parasymapthetic supply to constrictor pupillae and ciliary muscles via ciliary ganglion
Oculomotor N.
- innervation of upper eyelid and 4/6 extrinsic eye muscles
- Somatic: eye muscles
- Parasympathetic: constric pupil, contract ciliary muscle of lens
- originates at Edinger-Westphal nuclei in mesencephalon
- leaves cranium via superior orbital fissure and travels to eye
- ptosis, paralysis, strabismus, diplopoa, diff. focusing eye
Trochlear N. component and function
general somatic efferent
supplies the superior oblique muscle of the eye
What is the component and function of the trochlear N?
general somatic efferent
supplies the superior oblique muscle of the eye (inferior/lateral movement of eye)
Trochlear N.
- muscle that is being innervated acts as a pulley
- somatic: innervates superior oblique m.
- originates at trochlear nucleus within mesencephalon
- leaves cranium via superior orbital fissure and travels to superior oblique muscle
- strabismus, diplopia
What is the component and funciton of the Abducens N?
general somatic efferent
supplies lateral rectus M. of the eye
eye abduction
Abducens N.
- pulls eye laterally (ABduct)
- somatic: innervates lateral rectus
- originates at the pontine (abducens) nucleus in pons
- leaves cranium through superior orbital fissure and travels to lateral rectus M.
- limited ABduction, diplopia
Trigeminal N. branchial motor component and function
special visceral efferent
masticator muscles, tensory tympani, tensor veli palatini, mylohyoid, anterior belly digastric
trigeminal N. general sensory component and function
general somatic afferent
from face and scalp as far as top of head, conjunctiva, bulb of eye, mucous membranes of paranasal sinues, nasal and oral cavities, tongue & teeth, external TM, meninges of anterior and middle cranial fossa
Trigeminal N.
- three divisions, V1, V2, V3 (sensory and motor)
- sensory and somatic
- originates in the pons
- trigeminal neuralgia caused by inflammation in sensory components (v1 +2) causing intense pulsating pain for minutes to hours
Pathway of V1
sensory fibers enter cranium via superior orbital fissure and travel to trigeminal ganglion, before entering pons
pathway of V2
sensory fibers enter cranium via foramen rotundum and travel to trigeminal ganglion, before entering pons
Pathway of V3
motor fibers leave pons and exit cranium via foramen ovale to supply muscles
sensory fibers travel through foramen ovale to trigeminal ganglion before entering pons
structures innervated by Ophthalmic V1 of the trigeminal nerve
Lacrimal
Frontal (supratrochlear and supraorbital)
Nasalciliary (long/short, infratrochlear, ethmoidal)
meningeal branch (from tentorium cerebelli)
Structures innervated by Maxillary V2
Zygomatic
Infraorbital (external nasal and superior labial)
Superior alveolar
Palatine (orbital, greater and lesser, posteiror superior nasal, pharyngeal)
Meningeal (anterior and middle cranial fossa)
structures innervated by Mandibular V3
Sensory:
buccal
lingual
inferior alveolar
auriculotemporal
menigeal
Motor:
meidal pterygoid (tensor palatini and tympani)
lateral pterygoid
masseteric
deep temporal
mylohyoid (nerve to it and anterior belly of digastric)
What is the branchial motor component and function of the facial N?
special visceral efferent
supply:
stapedius, stylohyoid, post. belly of digastric, muscles of facial expression, including buccinator, platysmna, occipitalis M.
What is the visceral motor component of the facial N?
general visceral efferent
Supply:
stimulate lacrimal, submandibular, sublingual glands and mucous membranes of nose, hard and soft palates
What is the general sensory component and function of the facial N?
general somatic afferent
supply:
skin of ear, behind ear
What is the special sensory component of the facial N?
special afferent
taste and anterior 2/3 of tongue and hard and soft pallates
Facial N.
- innervates muscles of facial expression
- sensory, somatic, parasympathetic
- originates in the nuclei of the pons
- pathway: sensory travel from the tongue via chorda tympani through foramen to enter skull and synapses with geniculate ganglion. Somatic motor fibers leave the pons and enter temporal bone thru internal auditory canal, prkect thry temporal bone and emerge thru stylomastoid foramen to supply muscles. Parasympathetic motor fibers leave pons and enter internal auditory canal, leave greater petrosal nerve or chorda tympani and travel to autonomic ganglion before innervating glands
- dry eye/mouth, loss of taste, bell’s palsy.
Vestibulocochlear Nerve component and function
special sensory/afferent
supplies: auditory cochlea, balance
Vestibulocochlear N.
- equilibrium and hearing
- sensory
- vestibular branch originates from hair cells in the inner ear
- cochlear branch originates in the cochlea of the inner ear
- pathway: sensory cell bodies from vestibular ganglion or spiral ganglion merge and enter cranial cavity thru internal auditory canal and travel to junction of pons and the medulla oblongata
- lesions include loss of balance, n/v/dizziness, loss of hearing
branchial motor components of the glossopharyngeal nerve
special visceral efferent
supplies striated muscle, stylopharyngeus
Visceral motor component of the glossopharyngeal nerve
general visceral efferent
supplies the otic ganglion, sends fibers to stimulate the parotid gland
visceral sensory component and function of the glossopharyngeal n.
general visceral afferent
sensation from carotid body and sinus
general sensory component and function of the glossopharyngeal n.
general somatic afferent
general sensation to posterior 1/3 of tongue, skin on external ear and internal TM
Special sensory component and function of glossopharyngeal N.
special afferent
taste of posterior 1/3 of tongue
Glossopharyngeal N.
- taste of posterior 1/3 of tongue, 1 pharynx muscle, parotid gland
- sensory, somatic, parasympathetic
- sensory originates on taste buds of tongue and carotid bodies, motor originates in nuclei of medulla oblongata
- sensory travels along the inferior or superior ganglion into the jugular foramen and travels to pons. somatic motor leaves cranium via jugular foramen and tarvels to stylopharyneus. Parasympathetic motor travel to otic ganglion and then to parotid gland
- dry mouth, loss of taste in back of tongue
branchial motor component and function of the vagus n.
special visceral efferent
striated muscle of phrarynx, tongue, larynx. (except stylopharyngeus, tensor veli palatini)
visceral motor component of the vagus n.
general visceral efferent
smooth muscle of glands of the pharynx, larnx, thoracic and abd. viscera
visceral sensory component and function of the vagus n.
visceral afferent
from larynx, trachea, esophagus, thoracic and abd. viscera in aortic arch
general sensory component of the vagus n.
general somatic afferent
from skin on back of ear and exteranl acoustic mearus, external TM and pharynx
Vagus N.
- innervates structures of head and neck and in thoracic and abd. cavities
- sensory, somatic, parasympathetic
- originates in the motor nuclei of the medulla oblongata
- leaves cranium via jugular foramen before branching. Sensory neuron cell bodies located in superior and inferior ganglia assocaited with the nerve
- hoarsness, monotone, loss of voice, diff. swallowing, GI issues
branchial motor component of the spinal accessory nerve
special viscera efferent
supplies SCM and trap
Spinal accesory nerve
- innervates trap and SCM
- somatic
- spinal root origin: motor nuclei in spinal cord
- enter skull thru foramen magnum, cranial and spinal roots merge and leave the skull via jugualr foramen, split to travel with vagus
- trap and SCM paralysis, diff. shrugging shoulder, turning head contralaterally
hypoglossal nerve somatic motor component and function
general somatic efferent
supplies intrinsic and extrinsic muscles of the tongue except the palatoglossus (which is vagus)
hypoglossal n.
- innervates intrinsic and extrinsic tongue muscles
- somatic
- originates in the hypoglossal nucleus in the medulla oblongata
- leaves cranium via hypoglossal cana, travels to mandible and below tongue
- speech/swallowing issues, tongue deviation toward lesioned side
Visceral motor (parasympathetic) pathway the lacrimal gland
greater petrosal n. from CN VII at geniculate ganglion emerges from superior surface of petrous part of temporal bone to enter middle cranial fossa
greater petrosal n. joins deep petrosal n. (sympathetic) at foramen lacerum to form nerve of pterygoid canal
nerve of pterygoid canal travels thru pterygoid canal and enters pterygopalatine fossa
parasympathetic fibers from nerve of pterygoid canal in ptergopalatine fossa synapse in ptergopalatine ganglion
postsynaptic parasympathetic fibers from this ganglion innervate lacrimal gland via zygomatic branch of CN V2 and lacrimal nerve branch (from CN V1)
Visceral (parasympathetic) motor to submandibular and sublingual glands pathway
the chorda tympani branch arises from CN VII just superior to stylomastoid foramen
the chorda tympani crosses tympnaic cavity medial to handle of malleus
the chorda tympani passes thru petrotympanic fissure between tympanic and petrous parts of the temporal bone to join the lingual nerve (CN V3) in the infratemporal fossa
Parasympathetic fibers of chorda tympani synapse in submandibular ganglion; post-synaptic fibers follow arteries to glands
Shingles and the Trigeminal n.
tingles follow tracts, stop at crown (E distribution)
Left Abducent (CN VI) nerve palsy
right eye is normal and will abduct/adduct at will
left eye will not move, stays forward facing
right oculomotor (CN III) nerve palsy
right eye: downward and outward gaze, dilated pupil, eyelid manually elevated due to ptosis
left eye: normal
no antagnoist to pull straight forward
motion of oculomotor N.
moves eye upward and inward
eye motion of Trochlear N. and Abducent N.
Downward and Outward
know cranial nerve nuclei picture
