Face Flashcards
What muscle helps you close your eyes? (blink, etc)
Which helps with chewing/push food back over from cheek?
orbicularis oculi muscle
buccinator
What are the motor innervation of muscles of facial expression?
What is the sensory innervation of face?
motor- facial nerve (CN VII)
sensory- trigeminal nerve (Cranial Nerve V)
Where does the facial nerve (CN VII) exit the skull?
exits via stylomastoid foramen, pierces the parotid gland, as it passes through divides into 5 major branches
What are the 5 major branches that the facial nerve (CN VII) divides into as it exits the skull (from superior to inferior)?
(Ten Zebras Bashed My Car) Temporal Zygomatic Buccal Marginal/Mandibular Cervical
What happens if the facial nerve (CN VII) is injured just after it exits the stylomastoid foramen?
Bell’s Palsy. smoothing of forehead, eyebrow drop, drooping corner of mouth, can’t blink, drool
What are the three divisions of the Trigeminal nerve (CN V)?
ophthalmic division (just sensory) CN V1 maxillary division (just sensory) CN V2 mandibular division (motor and sensory) CN V3
anterior and posterior divisions… anterior is primarily motor and posterior primarily sensory.
Describe the nerves the ophthalmic division (CN V1) of the Trigeminal nerve (CN V) includes.
supraorbital supratrochlear infratrochlear external nasal lacrimal (LASSIE) (just sensory)
Describe the nerves the maxillary division (CN V2) of the Trigeminal nerve (CN V) includes.
zygomaticotemporal
zygomaticofacial
infraorbital
(Just sensory)
Describe the nerves the mandibular division (CN V3) of the Trigeminal nerve (CN V) includes.
auriculotemporal
buccal
mental
(sensory and motor)
What innervates the parotid gland?
parasympathetic fibers from the glossopharyngeal nerve (IX) which synapse in the otic ganglion (behind V3 as it exits foramen ovale) and then travel in the auriculotemporal nerve as it passes through the parotid gland.
What does the parotid gland secrete? Through what?
serous fluid via Stenson’s duct, which pierces buccinator muscle and enters the oral cavity adjacent to the upper 2nd molar. lays on masseter
What is the “Danger Triangle”?
if infection occurs in upper face, potentially bacteria can migrate from this region via the deep facial vein into the cranium.
Facial vein infection then can spread by its interconnections (ophthalmic and infraorbital veins) to the pterygoid plexus and into the cavernous sinus and thus reach brain causing meningitus or encephalitis
What are the layers of the scalp?
S-skin C-connective tissue (dense) A-aponeurosis L-loose connective tissue P-pericranium
What is immediately deep to scalp?
Cranial meniges:
dura mater, arachnoid mater, subarachnoid space (filled with CSF), pia mater
What is periorbital ecchymosis?
blood draining down from laceration on scalp, pool around forehead…black eyes resulting accumulation of blood from scalp
What is the Pterion?
What are the clinical implications of this area?
junction of parietal, temporal, sphenoid and frontal bones (all bones of temporal fossa)
(thinnest part of skull) middle meningeal artery runs deep to pterion is is vulnerable to injury/rupture in this region. Ruptrue of this artery leads to epidural hematoma
What two muscles work to close the jaw?
grinding and chewing?
temporalis muscle and masseter muscle
-ipsilateral masseter and temporalis, contralateral medial and lateral pterygoids…muscles act in a series, not all at once
What are some main contents of infratemporal fossa?
medial and lateral pterygoid muscles
maxillary artery and its 3 branches
mandibular division of the trigeminal nerve (CN V3) and its branches
sensory and motor of facial nerve
branches of CN IX (glossopharyngeal nerve)
What are the muscles of mastication?
What innervates them
lateral and medial pterygoid muscle
sphenomandibular ligament
masseter and temporalis
all innervated by branches of V3 (mandiular n)
What are some important points about TMJ?
All the muscles acting on the mandible directly or indirectly influence the function of the temporomandibular joint.
TMJ dysfunction has the potential to manifest as headaches, “dizziness”, “ear popping”, and jaw pain.
Several TMJ components serve as borders of the infratemporal fossa but entire complex is not a part of infratemporal fossa Several components of the TMJ are among the structures contained within the infratemporal fossa.
Describe the TMJ.
type of joint:
divisions:
superior/inferior parts relating to movement:
It is a synovial (diarthrodial) joint
It is a “modified” hinge type joint
Each joint is divided into a superior and inferior part by an articular disc.
The superior portion provides a gliding (sliding) movement. (this is second movement AFTER hinge movement completed)
The inferior portion provides for a hinge/rotational movement. (this lower compartment does the first movement)
Describe the maxillary artery.
What divides it?
What are the 3 regional parts?
Divided into 3 regions by lateral pterygoid muscle.
Mandibular part
Pterygoid part
Pterygopalatine part
What are the maxillary artery branches?
MIDBIPS Middle meningeal artery** Inferior alveolar artery (mental)** Ant/Post. deep temporal artery Buccal artery Infraorbital artery** Posterior sup. alveolar
Describe posterior division of the mandibular nerve (V3). 3 main nerves/specials.
Posterior (mostly sensory, anterior is mostly motor)
-auriculotemporal nerve
- lingual nerve
- inferior alveolar nerve
Describe the anterior division of the mandibular nerve (V3).
mostly motor
exception is buccal nerve which is sesnory to the external “cheek” and oral cavity
includes
nerve to masseter m
nerve to lateral pterygoid m
ant. and post. deep temporal nn. (innvervation to temporalis muscle)
Posterior division of mandibular nerve (V3):
auriculotemporal nerve function
2 special points
sensory to anterior ear and temporal region
Special #1: Lesser petrosal nerve (preganglionic parasympathetic) is derived from the glossopharyngeal nerve (CN IX) and runs to the otic ganglion where it synapses. The postganglionic fibers leaving the otic ganglion join (run with) the auriculotemporal n. to supply secretomotor fibers to the parotid gland.
Special #2: The auriculotemporal n. splits to encircle the middle meningeal artery (before it passes through the foramen spinosum) and then reunites to continue along its course in front of the ear.
Posterior division of mandibular nerve (V3):
Lingual nerve
special points
V3 general sensory innervation from the anterior 2/3rds of the tongue (pain, temp. and touch) travel in the lingual n.
Special #1: Receives the chorda tympani n (CN VII), which exits the petrotympanic fissure to enter the infratemporal fossa and join with the lingual n.
Chorda tympani supplies special visceral afferent (SVA) fibers for taste from the anterior two-thirds of the tongue.
Chorda tympani fibers traveling in the lingual nerve also carry preganglionic parasympathetics (GVE) which run to the submandibular ganglion (located immediately adjacent to submandibular gland) to synapse.
Postganglionic fibers from the submandibular ganglion provide the secretomotor innervation to the submandibular & sublingual glands.
Posterior division of mandibular nerve (V3):
Inferior alveolar nerve
special point
passes through the mandibular foramen, enters the mandibular canal, and supplies sensory innervation to the mandibular (lower) teeth. It then continues anteriorly & exits the mental foramen at which point it becomes known as the mental nerve.
Special #1: Before entering the mandibular foramen, the inferior alveolar nerve gives off a nerve known as the nerve to the mylohyoid. The nerve to the mylohyoid runs anteriorly & inferiorly to supply motor innervation to the anterior belly of the digastric & mylohyoid muscles.
What are the muscles that control movement of the jaw? protraction(anterior movement) retraction (posterior movement) elevation (closing) depression (opening)
protraction - lateral pterygoid (most imp. muscle) assisted by medial pterygoid, some contribution from masseter
retraction- posterior fibers of temporalis and deep fibers of masseter
elevation - temporalis, masseter, medial pterygoid
depresison - lateral pterygoid, digastric (mostly ant. belly) mylohyoid, geniohyoid, infrahyoid, gravity!!
Describe the mandibular division of the trigeminal nerve (V3) … where does it exit/enter?
what type of nerve?
exits the middle cranial fossa by passing through foramen ovale and enters the infratemporal fossa
anterior division- primarily motor
posterior-primarily sensory
What two arteries branch from the internal carotid artery?
supraorbital and supratrochlear arteries
Injury of what nerve could result in Bell’s Palsy?
Facial (VII)
Where do all the muscles of facial expression develop from? Which arch? What does this result in?
All the muscles of facial expression develop from an embryological structure known as the 2nd branchial arch and migrate into the superficial face; therefore they all share the same motor innervation – branches of the Facial Nerve (CN VII)
Where do muscles of facial expression originate and insert?
The numerous muscles of facial expression originate from bones of the facial skeleton and insert onto the skin of the face.
