Muscles of Face and Cranial Nerves Flashcards
what are the layers of the scalp
Skin
Connective tissue
Aponeurosis
Loose CT
Pericranium
where does scalping cleave?
the LCT
why is scalping dangerous
infection spreads easily in the LCT layer
dangerous because of connections with emissary veins that drain to veins inside the skull
what nerve innervates facial muscles
Facial nerve - cranial nerve VII
attachments and function of occipitofrontalis
occipital bone -> occipital belly -> epicranial aponeurosis -> frontal belly -> forehead skin
raises eyebrows
attachments and function of nasalis
maxilla near medial orbit -> alar cartilage of nose
flares nostril
attachments and function of orbicularis oculi
medial orbit->skin around orbit and eyelids
outer ring closes eye forcefully
inner ring closes gently
attachments and function of procerus
nasal cartilage -> skin between eyebrows
transverse wrinkle between eyes
attachments and function of orbicularis oris
medial maxilla, mandible, modiolus -> skin of lips
close, protrude lips
attachments and function of zygomaticus minor and major
zygomatic arch -> skin of upper lip
elevate, retract upper lip
attachments and function of levator anguli oris
maxilla near canines -> modiolus
elevate angle of the mouth
attachments and function of levator labii superioris
maxilla near inferior orbit -> skin of upper lip
elevate, retract upper lip
attachments and function of buccinator
mandible, maxilla, pterygomandicular raphe -> modiolus
presses cheek against teeth, resist distension, sphincter of parotid duct
how does the buccinator act as a sphincter for the parotid duct
parotid duct perforates buccinator bringing saliva from parotid salivary gland into oral cavity, if blowing air into cheeks buccinator prevents air entering duct
attachments and function of depressor anguli oris
mandible->modiolus
depress inferior lips
attachments and function of depressor labii inferioris
mandile -> skin of lower lip
depress, retract lower lip
attachments and function of mentalis
mandible near incisors -> skin of chin
elevate, protrude lower lip
attachments and function of platysma
supraclavicular skin -> mandible, skin of lower lip
depress mandible, tense skin on neck
what path does the facial nerve take
internal acoustic meatus -> facial canal -> stylomastoid foramen
enters parotid salivary gland and divides into 5 terminal branches
what are the 5 terminal branches of the facial nerve
Two Zebras Bought My Car
Temporal
Zygomatic
Buccal
Mandibular
Cervical
what is the cause of Bell’s palsy
idiopathic
maybe virus? inflammation, oedema, compression, ischaemia of nerve in bony facial canal
what are the signs of bell’s palsy
facial muscle paralysis, ptosis, dry mouth/eye (lacrimal gland) taste alteration, hyperacusis
what potential treatments are there for Bell’s palsy
steroids, eyedrops, tape eye closed at night
what is the action and uses of Botox
Botulinum toxin
blocks Ach release at NMJ
crows feet - orbicularis oculi
horizontal forehead wrinkles, frontalis
stabisimus crossed eyes
hyperhidrosis excessive sweating
what are the potential side effects of botox spreading
muscle weakness, double vision, trouble breathin, swallowing
how many pairs of cranial nerves are there
12 pairs
what is the only motor ONLY cranial nerve
spinal accessory nerve
describe the olfactory nerve (path and function)
cranial nerve 1
innervate nasal mucosa for sense of smell
pass superiorly through cribriform plate -> enter olfactory bulb -> signals travel back to brain via olfactory tract
describe the optic nerve (path and fucntion)
cranial nerve 2
sensory nerves of the retina travel to the brain via optic nerves
may cross at optic chiasm
travel in the optic tracts back to the brain
what are cranial nerves 3,4 and 6
oculomotor, trochlear and abducens
what is the function of cranial nerves 3,4,6
control the 6 muscles that move the eye
construct the pupil
3,4,6 make my eyes do tricks
what is the name of cranial nerve 5
trigeminal
describe the trigeminal nerve
forms a ganglion either side of the pituitary fossa and divides into V1,2,3
what is the function of V1-3
sensory innervation
face, orbital/nasal/oral cavities, sinuses, anterior tongue, teeth, meninges
what is the function of V3
motor innervation:
muscles of mastication, mylohyoid and digastric and 2 small muscles in ear and palate
sensory innervation divisions of the divisions of trigeminal nerve
supraorbital nerve - skin of forehead
branches of nasociliary - tip of nose
infraorbital - skin inferior to eye
lingual - anterior tongue
mental - skin of chin
describe the shingles
patient history of varicella caused by varicella zoster virus
virus lies dormant in a sensory nerve
virus reactivates if immune system is depressed->herbes zoster in area supplied by nerve
what is cranial nerve 7 called
facial nerve
describe the facial nerve (path)
enters internal acoustic meatus ->facial canal -> exits via stylomastoid foramen
what does the facial nerve supply
muscles of facial expression
what do the branches of the facial nerve supply
stapedius
digastric and stylohyoid muscles
taste (ant. tongue)
parasympathetic to: submandibular salivary gland and lacrimal gland of eye
what is cranial nerve 8
vestibulocochlear
describe the path and function of the vestibulocochlear nerve
inters internal acoustic meatus -> inner ear
supplies organs of balance (vestibule) and hearing (cochlea)
What is cranial nerve 9
glossopharyngeal
describe the glossopharyngeal nerve (path)
exits jugular foramen->rungs alongside stylopharyngeus muscle->enters pharynx and contributes to pharyngeal plexus
what innervation does glossopharyngeal give
sensory: pharynx and posterior tongue, carotid sinus, carotid body
taste: posterior tongue
motor: stylopharyngeus
parasympathetic to parotid salivary gland
where does the stylopharyngeus run from
styloid process to blend in with muscular pharynx
what is cranial nerve 10
vagus
describe the vagus nerve path
exits via the jugular foramen
runs down the neck between major vessels
continues into thorax and abdomen to supply parasympathetic innervation
where are the motor branches of the vagus nerve to
motor branches to: palate, pharynx and larynx
what is cranial nerve 11
spinal accessory nerve
describe the spinal accessory nerve path
technically arises from spinal cord
passes up through foramen magnum and enters jugular foramen
runs with carotid artery down neck and innervates sternocleidomastoid and trapezius
what is cranial nerve 7
hypoglossal
describe the path of the hypoglossal nerve
exits hypoglossal canal
runs anteriorly toward submandibular triangle of neck
what does the hypoglossal nerve give innervation to
hypoglossus
genioglossus
styloglossus
intrinsic tongue muscles
