Infratemporal fossa (dave's notes) Flashcards
Where is the infratemporal fossa found?
The space lying beneath the base of the skull between the side wall of the pharynx and the ramus of the mandible
What is the medial boundary of the the infratemporal fossa?
Lateral surface of the lateral pterygoid plate, tensor and levator palati muscles, superior constrictor
What is the lateral boundary of the infratemporal fossa?
Ramus of the mandible and its coronoid process
What is the anterior boundary of the infratemporal fossa?
The posterior surface of the maxilla (with its small foramina)
What is found at the upper border of the anterior surface of the infratemporal fossa?
The orbital fissure
What forms the roof of the infratemporal fossa?
Medially by the infratemporal surface of the greater wing of the sphenoid, and the adjacent squamous part of the temporal bone
What forms the posterior boundary of the infratemporal fossa?
The carotid sheath
List the contents of the infratemporal fossa
Medial and lateral pterygoids Intervening fat Temporalis insertion Maxillary artery Pterygoid plexus Mandibular nerve Otic ganglion Branches of the maxillary nerve
What is the origin and insertion of the lateral petrygoid?
Two heads; upper from infrateporal surface of skull, and lower from the lateral surface of the lateral pterygoid plate.
Passes back and is inserted via a short thick tendon ??petrygoid fovea, with the upper firers massing into the TMJ
What is the nerve supply to the lateral pterygoid?
The anterior division of the mandibular nerve.
What is the origin and insertion of the medial pterygoid?
Two heads. The larger deep head comes from the medial aspect of the lateral pterygoid plate and the depths of the fossa. The smaller superficial head arises from the maxillary tuberosity to fuse with the main jungle embracing the lower edge of the lateral pterygoid.
Inserted per the angle of the mandible
What is the nerve supply to the medial pterygoid?
Via a branch of the mandibular nerve.
What is the action of the medial pterygoid?
To pull the jaw upwards, forwards and medially
What is the action of the lateral pterygoid?
The action is to draw the condyle and disc forwards?
From what artery does the maxillary artery arise?
It is a terminal division of the external carotid artery.
How does the maxillary artery enter the infratemporal fossa?
By winding around the neck of the mandible
How many divisions does the maxillary artery have? How many branches per division?
Three divisions. 5,?6,5.
Where is the first part of the maxillary artery found? What is notable about the branches of the first part of the maxillary artery?
Before the lateral pterygoid. Five branches all of which enter foramen.
List the five branches of the first part of the maxillary artery
Inferior alveolar artery Middle meningeal artery Accessory meningeal artery Deep auricular nerve ?artery Anterior tympanic artery
Describe the location of and branches of the second part of the maxillary artery
On lateral pterygoid. Five branches to pterygoid muscle, deep temporal to temporalis
Where is the third part of the maxillary artery found? What is notable about the branches of the third part?
Beyond the lateral pterygoid, has five branches, all of which enter foramen.
List the branches of the third part of the maxillary artery
Posterior superior alveolar artery Greater palatine artery Pharyngeal artery Artery of the pterygoid canal Infraorbital artery
What is the course of the inferior alveolar artery?
Passes down and forward to the mandibular foramen where it enters with the vein and nerve, supplying teeth, mandible and some skin.
What is the course of the middle meningeal vein?
Passes up to foramen spinosum to the bone of the skull
What is the course of the accessory meningeal artery?
Passes up via foramen ovale to supply the dura mater over the floor of the middle fossa and trigeminal cave.
What is the destination of the deep auricular artery?
Passes up to supply the external acoustic meatus
What is the course and destination of the anterior tympanic artery?
Passes through the petrotympanic fissure to the middle ear.
What is the course of the posterior superior alveolar artery?
Passes through foramina in the posterior wall of the maxilla
What is the course and destination of the greater palatine artery?
Enters the greater palatine foramen to supply the hard palate
What is the size of, and destination of the pharyngeal artery?
Very small. Enters the palatovaginal canal
What is the course of the infraorbital artery?
Passes forwards throughout the inferior orbital fissure to emerge with the nerve on the face.
Give a mnemonic for the branches of the maxillary artery
DAM I AM Piss Drunk but Stupid Drunk I Prefer. Must Phone Alcoholics Anonymous
Using the mnemonic, recall the branches of the maxillary artery
Deep auricular
Anterior tympanic
Middle meningeal
Inferior alveolar
Accessory meningeal artery
Masseteric artery
Pterygoid Deep temporal Buccinator Sphenopalatine Descending palatine
Infraorbital
Posterior superior alveolar artery
Middle superior alveolar artery
Pharyngeal
Anterior superior alveolar artery
Artery of the pterygoid canal
What is the course of the artery of the ptrygod canal?
Runs in its own canal
Give the origin and destination of the posterior superior alveolar nerve
Branch of the maxillary which further divide into 2-3 dental branches which pierce the posterior wall of the maxilla
What is the pterygoid plexus? Where is it found? What does it drain?
A venous network within the lateral pterygoid muscle. These drain the area corresponding with the maxillary artery and the opthalmic veins (inferior orbital fissure).
What does the pterygoid plexus drain into?
Drains into the short maxillary veins to join the superficial temporal and retromandibular veins
What specialised function does the pterygoid plexus have?
Acts as a peripheral heart. Valved and compressible it drains non-compressible areas and acts as a pump via the movement of pterygoid.
What is the sphenomandibular ligament?
A flat band of fibrous tissue from the spine of the sphenoid to the lingular of the mandible (Perichnodrium of Meckel’s cartilage).
What is found between the sphenomandibular ligament and the neck of the mandible?
The auriculotemporal nerve, maxillary artery and vein
What is found between the sphenomandibular ligament and the ramus of the mandible?
The inferior alveolar vessels and nerve converge.
