Flashcards in Superficial Face and Parotid Region Deck (66)
The muscles of facial expression are striated muscles derived from which branchial arch?
Muscles of facial expression are innervated by motor branches of which CN nerve?
What are the muscles of the calvaria region?
the epicranius muscle, consisting of: occipitofrontalis (frontal and occipital bellies)
What do the muscles of the calvaria region do?
they are the muscles of the scalp and the frontal belly helps raise the eyebrows and wrinkle the skin of the forehead
What are the muscles of the orbital region?
the orbicularis oculi, consisting of the: orbital, palpebral, and lacrimal parts
What do the orbital and palpebral parts of the orbicularis oculi do?
the palpebral part gently closes the eyelids (so as to blink), while the orbital part closes them with more force (so as to wink or squint)
What is the main muscle of the mouth? What does it do?
orbicularis oris, it closes the mouth, protrudes the lips, and puckers the mouth
What does the buccinator m. do?
muscle of the cheek important in eating/drinking etc. This muscles presses the check against the molar teeth and is active during mastication to keep food out of the oral vestibule. It is also active to expel air from the oral cavity (blowing)
What does the levator labii superioris m. do?
elevates the upper lip and raises the angle of the mouth
What does the depressor labii inferioris m. do?
pulls the lower lip inferior and laterally
What do the zygomaticus major and minor mm. do?
pulls the corner of the mouth superior and lateral (smiling)
What does mentalis do?
pulls skin of the chin upward
What muscle travels over the brim of the nose?
What muscle inserts directly under the orbit?
the levator labii superioris
What muscle attaches to both the maxilla and zygomatic bones?
the levator labii superioris
What four facial muscles have attachments on the zygomatic bone?
the levator labii superioris, the zygomaticus minor and major, and deep masseter (from medial to lateral)
What muscles insert directly under the nostril ad extend down to the top of the orbicularis oris?
alar nasalis m. on each side
What muscle can be found directly medial to the alar nasalis m. inserting near the inferior border of the septum?
depressor septi nasi m
What muscle can be found directly deep to levator labii superioris?
levator anguli oris m. (on each side)- inserts on the maxilla bone
What three muscles can be found inferior to orbicularis oris from medial to lateral?
the mentalis, depressor labii inferioris, and depressor anguli oris at the corner of the mouth
What are the muscles of the inner eyebrow?
corrugator supercili m.
The parotid fascia is the superior continuation of which fascia?
the investing fascia of the neck
What muscle is the parotid gland directly superficial to?
the masseter (slightly posterior too as it wraps around it). The masseter m. fibers run vertically
What muscle does the parotid duct penetrate to enter the mouth?
the buccinator m.
What muscle does the parotid duct course on top of before piercing the buccinator m.?
What seperates the masseter (superficial) and the medial pterygoid (deep)?
What vein and artery are running just deep to the posterior aspect of the parotid gland?
the retromandibular vein and the external carotid a.
What nerve courses anteriorly over the external carotid a. and the retromandibular veins at the level of the condylar process of the mandible (just deep to the parotid gland)?
Deep to the parotid gland, what does this n. branch into?
the facial. The trunk of the facial n. can be found just anterior to the ear deep to the posterior aspect of the parotid gland.
the upper (temporofacial) and inferior (cervicofacial) divisions
After entering the internal acoustic meatus, where does the CN VII main trunk exit the cranial cavity?
the stylomastoid foramen (just after exiting it divides)
Parasympathetic innervation of the parotid gland comes from what?
the tympanic branch of CN IX via the otic ganglion
GSA from the parotid gland is relayed how?
C2 and C3 via the great auricular nerve and V3
What does the tympanic branch of CN IX do?
parasympathetic innervation (via the otic ganglion) to the parotid and GSA to the inner ear (internal tympanic membrane and auditory tube)
NOTE: its GSA cell bodies are in the inferior ganglion, located just outside of the jugular foramen
What canal does the tympanic nerve pass through in order to ascend to the tympanic cavity from the inferior (petrosal) ganglion?
the tympanic canaliculus (separates the carotid canal and the jugular foramen). After it passes through, it gives off the GSA fibers to the inner ear
Past the middle ear plexus, what does the tympanic nerve continue as?
the lesser petrosal nerve
How does the lesser petrosal n. course?
passes forward through the petrous part of the temporal bone and emerges through the hiatus of the lesser petrosal nerve onto the floor of the middle cranial cavity. it crosses the floor of the middle cranial cavity, passes through the foramen ovale and terminates in the otic ganglion (located just below the foramen ovale)
How do postganglionic fibers distribute to the parotid gland from the otic ganglion?
they run with the auricotemporal branch of V3 to the gland (an example of parasympathetics hitchhiking)
Where does the auricotemporal branch of V3 come from? What does it do?
the trigeminal ganglion (it provides GSA to the parotid capsule)
The cell bodies for the GSA distribution of the tympanic n. (branch of CN IX) are in the inferior ganglion. Where are the preganglionic cell bodies of the GVE parasympathetic distribution of the tympanic n.?
in the brainstem (postganglionic body is in the otic ganglion)
Sympathetic postganglionics to the parotid gland distribute via?
external carotid a. Sympathetic affects include vasoconstriction
The facial artery crosses the border of the mandible just anterior to which muscle?
The labial branch of the facial artery is given off as the facial artery courses vertically between which two muscles?
the zygomaticus major and minor
The posterior auricular branch of the external carotid a. branch immediately above which muscle?
the posterior digastric
The posterior auricular branch runs between which two bony structures of the skull?
the external acoustic meatus and the mastoid process.
It supplies the parotid gland!!
The transverse facial a. branches from the superficial temporal a. and distributes over which muscle?
The superficial temporal a. begins posterior to which gland?
The buccal nerve (branch of V3 ) does what?
sensory to the cheek area
The auriculotemporal nerve (branch of V3) does what?
sensory to the skin of the lower part of the external ear
What is the blood supply to the parotid gland?
posterior auricular a.
Does the maxillary a. run deep or superficial to the mandible?
What are the two main routes of venous drainages of the face?
IJV and EJV
The facial v. drains to what?
common facial with the anterior branch of the retromandibular v. (which then drains to the IJV)
What is the EJV formed by?
the confluence of the retromandibular v. and the posterior auricular v.
Are most parotid cancer benign or malignant?
benign. Malignant cancers often remain asymptomatic until they are big enough to press on a nerve.
Fairly low incidence (3-5% of all head and neck cancers)
Do parotid tumors affect the superficial or deep part?
What is the most common cause of non-traumatic facial paralysis?
inflammation of the facial nerve near its exit point at the SMF
The blood supply of the medial forehead mainly comes from what?
the ophthalmic a. from the ICA
What are the two muscles of the mandibular ramus sling?
the medial pterygoid and the masseter
What are the basic origin and insertion of the masseter m?
origin in the zygomatic arch and insertion in the angle of the mandible
What is the anterior border of the parotid bed?
halfway on the superficial portion of masseter
What is the posterior border of the parotid bed?
anterior margin of the SCM
What is the superior border of the parotid bed?
temporal bone and zygomatic arch
What is the function of the medial pterygoid and the masseter mm.?
elevating the jaw
The n. to mylohyoid runs with which artery?
the submental a. (branch of facial)
What are the two main post SMF branches of the facial n.?
temperalfacial and cervicalfacial
What are the branches of the temperofacial n.?
temporal, zygomatic, and buccal