Sensory and motor nerve supply of the head Flashcards
what nerve is the nerve of the first branchial arch
trigeminal
trigeminal nerve route
given off from the pons
passes to the middle cranial fossa
gives off three main branches: ophthalmic, maxillary, and mandibular
sensory role of the trigeminal nerve
major sensory nerve
external auditory meatus, nose, paranasal sinuses, mouth (except pos 1/3 of tongue), parts of nasopharynx, auditory tube and cranial dura matter
motor supply of trigeminal nerve
muscles of mastication
trigeminal ganglion cell bodies of sensory fibres that distribute along which branches
ophthalmic nerve (V1)
maxillary nerve (V2)
mandibular nerve (V3)
ophthalmic division of trigeminal nerve sensory innervation
structures derived from the frontonasal process
skin of face above the eye, eyeball, external nose
which nerves supply each limb of the corneal reflex
afferent limb: ophthalmic
efferent limb: facial
maxillary nerve sensory supply
structures derived from maxillary process
part of face below eyes, upper lip, palate, paranasal sinuses, upper teeth
mandibular nerve sensory supply
structures derived from the mandibular process
lower part of face, lower lip, anterior ear and chin, lower teeth, anterior 2/3 of tongue
motor supply of maxillary nerve
muscles of mastication
temporalis, masseter, medial and lateral pterygoid
lesion of trigeminal nerve
sensory loss on the face
weakness of the muscles of mastication that manifests as a deviation of the mandible toward the side of the lesion
sensory supply pathway of trigeminal nerve
trigeminal ganglion
spinal trigeminal nucleus (via trigeminothalamic tract)
ventroposterior medial nucleus of thalamus
primary somatosensory cortex
trigeminal neuralgia
common causes
marked by shock-like pain along nerve, especially radiating to the maxillary or mandibular area
aberrant blood vessels or aneurysms
compressing on trigeminal nerve at base of brain
what nerve is the nerve of the second branchial arch
facial nerve
facial nerve route
leaves the pons at the pontomedullary junction
enters the internal acoustic meatus
main trunk emerges from stylomastoid foramen to form terminal branches
large root of facial nerve
carries motor fibres to muscles of facial expression and stapedius
smaller root of facial nerve
nervus intermedius
taste fibres from ant 2/3 of tongue
secretomotor fibres to glands
terminal branches of facial nerve
temporal
zygomatic
buccal
marginal mandibular
cervical
motor supply of facial nerve to muscles
muscles of facial expression
upper face: frontalis, orbicularis oculi
lower face: zygomaticus major and minor, levator labii superioris, orbicularis oris
stapedius
motor supply of facial nerve to glands
parasympathetic supply
lacrimal gland
submandibular gland
sublingual gland
eye blink reflex of facial nerve
mediates closure of orbicularis oculi
facial nerve sensory supply
taste fibres from ant 2/3 of tongue
small number of fibres carry sensory fibres from external acoustic meatus and auricle
lesion of facial nerve
Bell’s palsy
distortion of the face, drooping of eyebrow, inability to close eye, sagging corner of mouth, inability to smile or blow
loss of taste in ant 2/3 of tongue, decreased salivary secretion and lacrimation, painful sensitivity to sounds
effect of facial nerve upper motor neuron lesion
part of the facial motor nucleus supplying the lower face only receives commands, from upper neurons of opposite cortex
part of the nucleus supplying upper face only receives commands from upper neurons from both cortex
paralysis of muscles in lower face but not upper face of opposite side
facial nerve upper vs lower motor neuron lesion effect on wrinkles
upper lesion shows wrinkles on both sides
lower lesion shows no wrinkles on affected side
glossopharyngeal nerve route
given off from medulla oblongata
leaves the skull through jugular foramen
glossopharyngeal sensory supply
pos 1/3 of tongue (sensation and taste)
soft palate, pharynx, middle ear, carotid sinus and body (baro- and chemoreceptors)
motor supply of glossopharyngeal nerve
one of the muscles of the pharynx
parotid gland (secretomotor)
glossopharyngeal nerve lesion
loss of afferent limb of gag reflex
glossopharyngeal neuralgia
can be caused by pharyngitis
manifests as sore throat and severe ear pain without ear infection
vagus nerve route
given off from the medulla oblongata
leaves the skull through the jugular foramen
motor supply of vagus nerve
muscles involved in swallowing and voice production
most of soft palate and pharynx muscles, muscles of larynx
which nerves mediate each limb of the gag reflex
afferent limb: glossopharyngeal
efferent limb: vagus
lesion of vagus nerve (head specific)
loss of gag reflex with uvula deviating away from side of lesion, toward intact side
dysphagia
dysphonia
loss of cough and sneeze reflex
accessory nerve components
cranial accessory and spinal accessory nerves
accessory nerve route
cranial accessory given off from medulla oblongata
spinal accessory given off from spinal cord
both roots leave the skull through jugular foramen
cranial fibres join vagus nerve
cranial accessory nerve motor supply
branches of vagus nerve
muscles of pharynx and larynx
spinal accessory nerve motor supply
sternocleidomastoid
trapezius
lesion of spinal accessory nerve
torticollis (wry neck)
paralysis of sternocleidomastoid and shoulder drop of trapezius
hypoglossal nerve route
leaves medulla oblongata
passes through hypoglossal canal in the skull
hypoglossal motor supply
almost all the muscles of the tongue
lesion of hypoglossal nerve
causes tongue to deviate to injured side during protrusion of tongue
