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