Face anatomy Flashcards
intracranial course of facial nerve
origin between pons and medulla
internal acoutstic meatus
facial canal in the petroud part of the temporal bone
exit through the stylomastoid foramen
branches of facial nerve in the face
the zebra buggered my cat
divides into 5 branches as it enters the parotid
temporal
zygomatic
buccal
marginal mandibular
cervical
cranial nerves that transmit parasympathetic fibers
occulomotor
facial
glossopharyngeal
vagus
surface anatomy of the parotid gland
tragus, mandible, middle of mastoid
duct = middle 1/3 of line from intertrgaic notch to philtrum
what is the opening of the parotid gland
stensen’s duct
adjacent to the upper 2nd molar
path of parotid duct
crosses the masseter, pierces buccinator
opens next to 2nd molar
structures passing through parotid gland
facial nerve - most superficial
ECA
Retromandibular vein
auriculotemporal nerve (branch of V3)
deep parotid LNs
relations to the parotid gland
anterior - masseter, medial pterygoid, superfiial termportal and maxillary arteries, facial nerve, stylomandibualr ligament
posterio - posterio belly digastric, SCM, stylohypod, ICA, matoid process, styloid process.
arterial supply to the parotid
ECA
venous drainage of parotid
retromandibular = union of superficial temporal and maxillary
lymphatic drainage parotid
deepa d superficial partid nodes - upper deep cervical
nerve innervation of parotid
parasympathetic - secretomotor from otic ganglion
sympathetic - superficial cervical ganglion
sensory - greater auricular nerve
types of parotid gland secretion
serous
parasymptathetic - watery
sympathetic - low-volume, enzme rich
differentials of a parotid lump
infection - parotiditis, mumps
obstructed duct - internal or external comression
neoplasm - pleomorphic adenoma warthin’s tumour
deep parotid LNs
frey syndrome
damage to the parasympathetic fibres from the auricolotemporal nerve resulting in excessive gustatory sweatingin response to salivary stimulus
where to palpate the facial artery
as it crosses the inferior border of the mandible adjacent to the anterior border f the masseter
what artery is the temporal pulse
superficial temporal
where does the submandibular duct open
floor of the mouth, either side of the frenulum
submandibular gland secretion
mucous and serous
nerves at ris of injury in submandibular gland excision
marginal mandibular (branch of facial)
lingual
hypoglossal
difference between UMN and LMN facial palsy
UMN lesion upper part fo the faci will be spared
LMN both the upper an dlower part of the face is affected
regions drained by the pre-auricular LNs
upper half of the face
temporal region
auricle and external acoustic meatus
gums
what do melanoma mets look like microscopically
pigmented cells
nerve supply to the tongue
all of the motor innervation from the hypoglossal nerve (except palatoglossus - vagus)
posterior 1/3 - sensory and taste = glossopharyngeal
anterior 1/3 - taste = chorda tympani (VII), sensation = lingual (mandibular V3)
extrinsic muscles of the tongue
genioglossus, hypglossus, styloglossus
supplied by hypoglossal nerve
palatoglossus suplied by vagus
muscle retracting the tongue
sttyloglossus
what makes up the roof of the middle ear
tegmen tympani
how do middle ear infections cross the skull?
direct erosion of tegmen tympani
may also spread throug mastoid air cells causing mastoidiitis
clinical picture of meningism
photophobia, neck stiffness, fever
identify internal auditory meatus
temporal bone between posterior cranial fossa and middle ear
structures passing through IAM
facial nerve
vestibulocochlear nerve
7 and 8
what can make irreversible damage to the vestibulocochlear nerve
acoustic neruoma
why does a patient with an acoustic neuroma hear loud noises on the affected side?
facial nerve involvement with paralysis of the nerve to stapedius
relations of the middle ear
roof - tegmen tympani
floor - thin bone between tympanic cavity and INjternal juglular vein
anterior - thinbone between tympanic cavity and ICA
posyerior wall - mastoid
medial mall - inner ear
lateral wall - tympanic membrane
parasympathetic ganglion occulomotor nerve
target organ: pupil (constriction)
ciliary ganglion
parasympathetic ganglion facial nerve
target organ: Lacrimal glands, nasal mucosa, submandibular and sublingual salivary glands
pterygopalatine ganglion
submandibular ganglion
parasympathetic ganglion glossopharyngeal
target organ: parotid
otic ganglion
vagus parasympathetic ganglions
thoracic and abdomianl viscera
diffuse ganglions
cranial nerves and sympathetic nerves
no cranial nerve carries originating sympathetic fibres
Preganglionic sympathetic fibers:
Originate from T1-T3 spinal cord levels → ascend to superior cervical ganglion.
Postganglionic sympathetic fibers:
Travel on carotid arteries (internal/external).
Hitchhike on branches of CNs V1 (ophthalmic), V2 (maxillary), V3 (mandibular) to reach their targets.
Influence pupil dilation (dilator pupillae muscle), sweating, vasoconstriction, eyelid elevation (minorly via Müller’s muscle).
disruption anywhere along chain results in horners syndrome
