Flashcards in parotid region Deck (52)
what 4 things does the parotid region contain?
parotid gland & duct
facial nerve (CN VII)
what are the boundaries of the parotid region?
Superior to angle of mandible, inferior to zygomatic arch
Anterior to auricle & sternocleidomastoid
Posterior to anterior border of masseter
Superficial to ramus of mandible
what is the parotid gland enclosed in? where are its apex (posterior to what?) and base? (parallels what?)
Enclosed in investing layer of deep cervical fascia
Apex-posterior to angle of mandible
Base-parallels zygomatic arch
what is the course of the parotid duct?
Duct courses over superficial surface of masseter, turns inward to pierce buccinator
Ostia opposite 2nd upper molars
what 3 structures are imbedded in the parotid gland? (superficial to deep)?
Parotid plexus of facial nerve: 5 branches
External carotid artery
what type of innervation is the parotid gland? what are the 3 parts (pregang, synapse, post-gang)?
which would the "innervation name" be referring to?
Preganglionic-glossopharyngeal (CN IX)
Synapse: otic ganglion in infratemporal fossa
Postganglionic-auriculotemporal branch of trigeminal (CN V3)
*INNERVATION: PREGANG: GLOSSOPHARYNGEAL CN IX
what are the three branches of the trigeminal? which gives off parotid branches?
CN V (trigeminal) - V1, V2, V3
V3: mandibular- auriculotemporal branch - which then gives off parotid branches
boundaries of temporal region (anterior/inferior, posterior, medial, deep, superficial)
Anterior & inferior to temporal lines
Posterior to frontal & zygomatic bones
deep to zygomatic arch
Superior to infratemporal crest of sphenoid
Superficial to frontal, parietal, temporal, & sphenoid bones (pterion)
what is the function of the temporalis investing fascia?
stops at zygomatic arch- acts as a stabilizing force - the muscle pulls the coronoid process upwards and the fascia stabilizes this.
example:if you put the opposite hand on a bench (fascia) to stablize, and the hand on the dumbell pulling up is the muscle - in a lat pull
what are the two processes of the mandible?
temporalis muscle: floor
floor: pterion (frontal, parietal, temporal, & sphenoid)
what 4 bones meet to make the pterion?
frontal, parietal, temporal, & sphenoid
boundaries of the infratemporal fossa (medial, lateral, inferior, superior)
Medial to ramus of mandible
Lateral to lateral pterygoid plate of sphenoid
Inferior continuation of temporal fossa, inferior to greater wing of sphenoid
Superior to medial pterygoid muscle
boundaries of infratemporal fossa (posterior, anterior)
Posterior to maxilla
Anterior to mastoid/styloid processes & tympanic plate of temporal bone
what are the 4 communications through the infratemporal fossa? (
1. inferior orbital fissure --> orbit
2. foramens ovale & spinosum--> mid cranial fossa
3. pterygomaxillary fissure --> Pterygopalatine fossa via
4. mandibular foramen (on mandible- lower than fossa) --> oral cavity
contents of the infra temporal fossa? (5)
Inferior portion of temporalis muscle
Medial & lateral pterygoid muscles
Maxillary artery & branches
Mandibular branch of trigeminal (CN V3) & branches
what are the 4 muscles of mastication? what are they all innervated by?
In: mandibular division of trigeminal nerve (CN V3)
what is the actions of the temporalis, masseter + pterygoids? what one action are they not the main force in?
Produce movements of TMJ-elevation/depression, protrusion/retrusion, lateral
* Depression: Gravity is main force for this
temporalis muscle: O,I,A,In
O-temporal fossa & deep surface of temporal fascia
I-coronoid process of mandible
A- Elevates & retracts mandible
Inn- deep temporal branch of CN V3
masseter muscle: O,I,A,In
O-maxillary process of zygoma
I-lateral angle & ramus of mandible
A- Elevates mandible
Inn- masseteric branch of CN V3
which masstication muscle has two heads?
(superior and inferior heads- two different origins + insertions)
lateral pterygoid muscle: O, I
(* originates anterior, Inserts more posterior)
O-superior head: infratemporal surface of GREATER WING SPHENOID;
inferior head: lateral surface of LATERAL PTERYGOID PLATE
I-superior head- inserts on cartilage between head of mandible + mand. fossa (ARTICULAR DISC OF TMJ)
inferior head- inserts on head of mandible directly (CONDYLOID PROCESS/HEAD OF MANDIBLE)
lateral pterygoid muscle- Action and Innervation
A- Protracts mandible (bilateral), moves mandible to contralateral side (unilateral)
Inn- lateral pterygoid branch of CN V3
medial pterygoid muscle- O,I,A,Inn
O-medial surface of lateral pterygoid plate
I-medial angle & ramus of mandible
A- Elevates mandible
Innervated by medial pterygoid branch of CN V3
which muscles elevate the mandible?
temporalis (retracts as well), masseter, and medial pterygoid
what does the TMJ joint do?
Modified hinge joint
-Pivoting (lateral movements)
TMJ joint space is completely subdivided by what? what does this subdivide the space into? what inserts here?
Joint space completely subdivided by articular disc- creates superior + inferior articular cavities
- Insertion of superior head of lateral pterygoid
TMJ movements:Protraction/retraction occurs between ______ & _____
Elevation/depression & pivoting occur between ____ & ______
protract/retract: temporal bone & disc
elev/depression: disc & condyle
TMJ movements: depression requires simultaneous ____. unilateral protraction generates what ______ _______
Depression requires simultaneous protraction
Unilateral protraction generates contralateral pivoting