L13: Infratemporal Fossa Flashcards
Temporal Fossa bounds
- Ant: frontal, zygomatic bones - Post/sup: temporal lines - Lat: zygomatic arch - Inf: infratemporal crest - Floor: frontal, parietal, temporal and greater wing of sphenoid (pterion)
Muscles of temporal fossa
- Temporalis muscle (except inf portion) - Masseter muscle
O/I/A temporalis muscle
- O: floor of temporal fossa and fascia - I: tip and medial surface of coronoid process and ant border of ramus of mandible - A: elevates and retracts mandible - I: CN V3
O/I/A/I masseter muscle
- O: zygomatic arch/bone - I: ext surface of ramus and angle of mandible - A: elevates and protrudes mandible (mastication) - I: CN V3
Infratemporal fossa bounds
- Lat: ramus of mandible - Med: lateral pterygoid plate - Sup: infratemporal crest - Inf: angle of mandible
Contents of infratemporal fossa
- Temporalis m (inf portion) - Medial pterygoid m - Lateral pterygoid m - Maxillary artery - Pterygoid venous plexus - Mandibular division of CN V with branches - Chorda tympani - Otic ganglion
Branches of external carotid artery?
- Some anatomists like fornication, others prefer S&M - Sup thyroid, ascending pharyngeal, lingual, facial, occipital, post auricular, sup temporal, maxillary
Two terminal divisions of ext carotid a? Which is largest?
- Maxillary and superficial temporal - Maxillary is largest
Identify landmark where maxillary artery arises
- Post to neck of mandible (inferior to coronoid process)
What muscle divides maxillary artery?
- Lateral pterygoid m
Divisions of maxillary artery
- Mnemonic: DAM I AM Piss Drunk But PISD a.) 1st part: - Deep auricular - Ant tympanic - Middle meningeal - Inf alveolar - Accessory meningeal b.) 2nd part: - Masseteric - Pterygoid - Deep temporal - Buccal c.) 3rd part: - Post sup alveolar - Infraorbital - Sphenopalatine - Descending palatine
Destination of maxillary artery branches
- Mnemonic: DAM I AM Piss Drunk But PISD d.) 1st part: - Deep auricular: ext acoustic meatus - Ant tympanic: to TM - Middle meningeal: to cranial meninges - Inf alveolar: mandibular teeth - Accessory meningeal: to cranial meninges e.) 2nd part: - Masseteric: masseter m - Pterygoid: pterygoid muscles - Deep temporal: temporalis m - Buccal: muscles of cheek f.) 3rd part: - Post sup alveolar - Infraorbital - Sphenopalatine - Descending palatine
Through what foramina do the middle and accessory meningeal arteries travel?
- Middle: foramen spinosum - Accessory: foramen ovale
O/I/A/I of medial pterygoid muscle
- O: medial surface of lat pterygoid plate - I: internal surface of ramus - A: mastication - I: CN V3
O/I/A/I of lat pterygoid muscle
- O: lat surface of lat pterygoid plate - I: TMJ and neck of condyloid process - A: mastication - I: CN V3
Major inlets and outlets of pterygoid venous plexus
- Inlet: facial vein, cavernous sinus - Outlet: maxillary veins into sup temporal vein (in parotid) into retromandibular vein
Muscles of mastication
- Temporalis, masseter, lateral and medial pterygoids
Innervation of muscles of mastication
- CN V3
What innervates muscles of facial expression?
- CN VII
Foramen that CN V3 exits?
- Foramen ovale
Is CN V3 motor or sensory?
- Both
What do the motor branches of CN V3 innervate?
- Masticatory muscles - Mylohyoid - Ant belly digastric - Tensor tympani - Tensor veli palatini
Sensory branches of CN V3?
- Mnemonic: Buccaneers Are Inferior Linguists - Buccal nerve - Auriculotemporal - Inferior alveolar nerve (mylohyoid, mental, incisive) - Lingual nerve
What do the sensory branches of CN V3 carry?
- Buccal = skin of cheek, mucous membrane of cheek and lateral surface of oral gingival - Auriculotemporal (auricle, skin over temporal, TMJ, secretory PSNS parotid fibers belonging to CN IX, ext acoustic meatus and TM) - Inf alveolar (teeth on its side) - A.) mylohyoid n = ant belly digastric, mylohyoid m - B.) mental n = skin of chin - C.) incisive n = canine and incisive teeth - Lingual = sensory to tongue, floor of mouth and gingival
Course of chorda tympani. Origin, Function?
- Branch of CN VII - CN VII enters through internal acoustic meatus, travels into facial canal gives off chorda tympani which travels through the petrotympanic fissure and joins with lingual nerve (CN V3). Has preganglionic PSNS fibers to submandibular ganglion. CN VII leaves via stylomastoid foramen. - Function: taste from ant 2/3rds tongue (except taste to vallate papillae)
Describe PSNS pathways into and out of otic ganglion – what do these fibers innervate?
- In: preganglionic PSNS fibers from CN IX via tympanic nerve into tympanic plexus into lesser petrosal nerve
- Out: postganglionic PSNS fibers with auriculotemporal nerve (V3) to parotid gland
What type of joint is TMJ? Describe in detail
- Modified hinge joint w/ - Synovial joint between mandibular fossa / articular eminence of temporal bone & condyle of mandible - Articular surfaces covered by fibrous tissue - Articular disc = fibrous tissue - Upper = between articular eminence, mandibular fossa and articular disc = gliding joint - Lower = bw articular disc and condyle of mandible = hinge joint
Ligaments of TMJ
- Stylomandibular - Sphenomandibular - Lateral ligament
What nerve encircles and artery on the head?
- Auriculotemporal (V3 division) encircles middle meningeal artery
What muscles open the mouth?
- Supra/infrahyoids
What muscles close the mouth?
- Temporalis and masseter
What muscles protrude the jaw?
- Lateral pterygoids and masseter
What muscles retrude the jaw?
- Posterior fibers of temporalis
What muscles laterally move the jaw?
- Temporalis (on side of lateral movement) with lateral pterygoid on opposite side
Nerve supply to TMJ?
- Masseteric - Auriculotemporal
