Infra-temporal fossa and parotid gland Flashcards
week 13
What is the temporal fossa primarily formed by?
squamous portion of the temproal bone
What is the pterion?
what does it mark?
an H-shaped zone of suture fusion of the parietal, frontal, sphenoid and temporal bones.
marks the intracranial location of the middle meningeal artery
What is the zygomatic arch formed by?
zygomatic bone and the zygomatic process of the temporal bone
the mandible corpus contains what on the anterior aspect of the body?
what on the superior aspect?
the mental foramen is present on the anterior aspect of the body
the superior aspect contains the alveolar process for the lower dentition
talk about the ramus of the mandible
-the ramus has the coronoid and condylar processes
- the condylar porcess articulates with the skull via the TMJ
- the condylar process has an articular head with a narrow neck
Where does the mandibular notch lie between?
the condylar and the coronoid processes
the inferior portion of the ramus of the mandible is referred to as?
the angle of the mandible
a medial side of the mandible body contains?
mylohyoid line
the medial aspect of the ramus contains ________ _______ that the inferior alveolar nerve and blood vessesl enter as they supply the?
mandibular foramen
supply the inferior teeth
what is the name of the bony projection that extends out in the areaof the mandibular foramen?
what is it a site of attachment for?
lingula
- site of attachment of the sphenomandibular ligament, which runs from the spine of the sphenoid to the lingula of the mandible
what is the attachment sites of the sphenomandibular ligament?
runs from the spine of the sphenoid to the lingula of the mandible
where is the temporal fascia attached to?
if the temporal fascia is removed, what is revealed below?
the fascia is attached to the zygomatic arch and the superior temporal line
- removal of teh temporal fascia reveals the temporalis muscle which is fan shaped
what is the origin of the temporalis muscle?
what is the insertion?
- tempral fascia, temproal fossa and inferior temoral line
- via tendon on the coronoid process of the mandible and the anterior margin of the ramus
what is the action of the temporalis muscle?
talk about the fibers of the temoralis muscle and the role they play in the action of the muscle.
elevation and retraction of the mandible
- has both horizontally and vertically oriented fibers. the horizontally oriented fibers retract the mandible, while the vertically oriented fibers elevate teh mandible (close the jaw)
what is the origin and insertion of the masseter?
what is the nerve supply and action?
- lateral ventral surface of the zygomatic arch
- lateral surface of ramus
- nerve supply: masseteric branch of CN V^3
- action: elevation of the mandible
What is the origin insertion of the medial pterygoid muscle?
what is the nerve supply and action?
origin: medial side of the lateral pterygoid plate; fibers course inferiorly and posteriorly
insertion: medial aspect of the ramus of the mandible
nerve supply: medial pterygoid branch of CN V^3
action: elevation and protrusion of the mandible
lateral pterygoid muscle:
origin:
insertion:
nerve supply:
action:
lies superficial to the medial pterygoid
origin: superior head -infratemporal crest; inferior head-lateral side of the lateral pterygoid plate
insertion: superior head - capsule of the TMJ; inferior head: necl of the mandible
nerve supply: lateral pterygoid branch of CN V^3
action: protrusion of the mandible by action on the TMJ and mandible
infratemporal fossa:
boundries
anteriorly:
posteriorly:
superiorly:
inferiorly:
mediallly:
laterally:
floor:
It is bounded by the following structures:
anteriorly, by the body of the maxilla
posteriorly, by the articular tubercle of the temporal and the sphenoid spine
superiorly, by the greater wing of the sphenoid below the infratemporal crest, and by the under surface of the temporal squama
inferiorly, by the alveolar border of the maxilla
medially, by the lateral pterygoid plate
laterally, by the ramus of mandible
Floor is formed by the Medial pterygoid muscle (superior surface where it insets into the mandible)
where is the pterygomaxilllary fissue located?
what does it lead to?
the medial aspect of the anterior boundary- pterygomaxillary fissue is a slit like opening
the fissure leads into the pterygopalatine fossa and nasal cavity, as well as the inferior oribital fissure
The maxillary artery is one of two terminal branches off of the?
what is the other terminal branch?
external carotid artery
the other terminal branch is the superificial temproal artery
The maxillary artery arises within the ? and enters the ?
the maxillary artery arises within the parotid gland and enters the infratemporal fossa by passing deep to the ramus of the mandible
What fossa does the maxillary artery cross that gives off branches as it courses medially? it will exit the fossa by entering ?
infratemporal fossa
and it will exit the fossa by entering the pterygomaxilllary fissure
where do the branches of the maxillary artery go?
1) Two branches go to the ear (deep auricular and anterior tympanic)
2) The inferior alveolar artery enters the mandible via the mandibular foramen. It courses forward within the mandible, supplying the lower teeth and the mandible. It terminates as the mental artery.
3) The middle meningeal artery enters the skull via the foramen spinosum.
4) The accessory meningeal artery is inconsistent. It enters the skull via the foramen ovale. Most blood supplies extracranial structures, some reaches trigeminal ganglion.
5) Muscular branches go to the temporalis muscle (deep temporal arteries), the pterygoid muscles, masseter muscle, and the buccinator (buccal artery).
6) The posterior superior alveolar artery enters the body of the maxilla to supply the upper teeth, posteriorly.
7) The infraorbital artery courses superiorly near the maxilla to enter the inferior orbital fissure.
The rest of the maxillary artery enters the pterygomaxillary fissure where it terminates by splitting into the sphenopalatine and descending palatine arteries.
What veins drains the area supplied by the maxillary artery?
what does these veins connect with?
what are they possible routes for?
pterygoid plexus of veins
1. there are usually double veins (venae comitantes) that lie on either side of the artery
2. the pterygoid veins connect with veins in the interior of the skull and are valveless
3. they are possible routes for transmission of infection
Where does the CN V^3 enter the infratemporal fossa from?
the middle cranial fossa by coursing through the foramen ovale, deep to the lateral pteryoigd muscle
mandibular division of the trigeminal nerve
What nerve is the sensory branches of the CN V^3 mandibular?
what are the the motor branches?
parasympathetic innervation supplied by what nerve?
all of these nerves exit from what?
sensory branch: buccal nerve, mental n, ligual n, taste from 2/3 of tongue, inferior alveolar n, chorda tympani (facial n.), n to mylohyoid
motor branches: deep temporall nn. masseteric n. n to lateral pterygoid, n to mylohyoid, iferior alveolar n.
parasympathetic innervation from the facial nerve., chorda tympani (facial n.), lingual n., submandiublar ganglioin
they all exit from foramen ovale
What are the sensory branches, motor branches, and parasympathetics from the glossopharyngeal n. via CN V^3?
what do they exit from?
sensory: auriculotemporal n., EAM, ear drum
motor: N/A
parasympathetics via glossopharyngeal n.: auriculotemporal n.
exit form: foramen spinosum
talk about the inferior alveolar nerve:
enters the mandibular foramen with the artery of the same name.
- gives off a small mylohyoid branch just prior to entry into the mandible.
- courses through the ramus and body of mandible, supply sensory innervation to lower teeth, amdnible and lower lip
- gives off the mental nerve, which exits the mandible via the mental foramen and provides sensory innervation to the chin
- gives off a small mylohyoid branch jsut prior to tnery into the mandible
the inferior alveolar nerve gives off what other nerve branches?
- mental nerve
- mylohyoid branch
talk about the lingual nerve:
- courses deep to the ramus adn body of the mandible to reach the tongue
- in the infratemporal fossa joined by a small nerve, the chorda tympani which is a branch of the facial nerve
the chorda tympani is a branch of what nerve?
carries special sensory fibers for what?
- branch of the facial nerve
- carries special sensory fibers for tast to the anterior 2/3 of the tongue, and preganglionic parasympathetic fibers
auriculotempral nerve arises via?
two roots that encurcle the middle meningeal artery as it eneters the foramen spinosum . the roots joint lateral to the artery
the auriculotemporal nerve provides sensory to what area?
the nerve also carries what other kind of fibers?
area in front of the ear, the parotid gland adn teh temporal region
the nerve also carries postganglionic paraysmpathetic fibers from the otic ganglion to the parotid gland
what is stern’s hierarchical law?
- tensor = trigeminal
- palat = vagus, except tensor veli palatini
- gloss = hypogossal except palatoglossus
what does the TMJ articulate between?
condylar head of the mandibe and the madnibular (glenoid) fossa and articular surface (process) of the temporal bone
What kind of joint is the TMJ?
synovial joint with an intra-articular disc
1. the disc divides the joint into superior and inferior compartments
The inferior compartment of the TMJ permits what kind of movement?
the superior compartment of the TMJ permits what kind of movement?
inferior compartment = hidge movement of the condylar head
superior compartment permits a gliding motion that moves the head of the mandible from the mandibular fossa onto the artiuclar surface of the temoral bone.
the movement of the superior compartment of the TMJ is due to the action of what muscle?
lateral pterygoid muscle
the parotid gland has parts of waht two nerves traveling through it?
- facial
- great auricular nerve
parasympathetic innervation to the parotid glad is from what nerve?
glossopharyngeal nerve (CN IX)
