What is ptertion?
Ptertion is the junction of the parietal, temporal, sphenoid and frontal bones.
What artery supplies the meninges and the skull?
Middle meningeal artery. Rupture of this artery leads to an epidural hematoma.
Temporalis muscle. Insertion? Innervation? Function?
Inserts: Onto the coronoid process of the mandible and small part of the anterior ramus of the mandible
Innervation: V3 (tigeminal nerve branch 3)
Function: elevate the jaw and assist in retraction.
Masseter Muscle
Essentially the Massester muscle is the inferior part of the temporal fossa due to its origin.
Origin: Inferior border of the zygomatic arch.
Inserts: Superficial fibers:Onto the angle of mandible and part of ramus. Deep fibers: onto the lateral aspect of coronoid process of mandible.
Innervation: Nerve to the massester V3. (passes through mandibular notch along with blood supply)
Function: elevate the mandible and protract the mandible (pull jar slightly forward)
What are the borders of the Infratemporal Fossa?
What foramen do they contain?
What structures are on the different walls of the Infratemporal Fossa?
Supermedially?
Superiormedially wall contains:
What structures are on the different walls of the Infratemporal Fossa?
Anterior wall?
2. Inferior Orbital Fissure
What structures are on the different walls of the Infratemporal Fossa?
Lateral wall?
Note: the inferior alveolar nerve and artery pass through the mandibular foramen.
What nerve and artery passes through the mandibular foramen?
the inferior alveolar nerve and artery pass through the mandibular foramen.
What structures are on the different walls of the Infratemporal Fossa?
Medial wall?
What muscles, arteries, and nerves are int eh infratemporal fossa?
Note: The glosspharyngeal nerve synapses in the otic ganglion.
Lateral pterygoid muscle. Origin? Insertion? Innervation? Function?
Originate: As two heads one superior and one inferior.
Inserts: Uniquely on TMJ(superior head) and mandible(inferior head)
Innervation: nerve of the lateral pterygoid (branch of V3)
Function: Primarily to open the jaw. The inferior head can protrude the jaw, while the superior head acts on the articular disc i.e to grind food.
Medial pterygoid muscle. Association? Origin? Insertion? Innervation? Function?
Association: It is deep to the lateral pterygoid and runs parallel to the massester muscle.
Origin: Also from two heads. A deep (medial surface of the lateral pterygoid plate) and superficial (from the tuberosity of the maxilla and the pyramidal plate of palatine)
Inserts: the medial surface of the mandible near the angle.
Innervation: Medial pterygoid nerve (branch of V3)
Function: to elevate and protrude the mandible. Note it works also to grind food.
What muscles assist in lateral displacement of the jaw? (i.e grinding and chewing).
Do these muscles act in series or concert?
Important to note that these muscles act in series.
What muscles assist in jaw protraction?
What muscles assist in jaw retraction?
2. Deep fibers of Masseter
What muscles assist in jaw elevation?
What muscles assist in jaw depression?
Is the entire TMJ comples part of the infreatemporal fossa?
NO. But several components serve as borders.
What kind of joint is the TMJ complex? What is different about it?
It is a synovial joint that DOES NOT CONTAIN HYALINE CARTILAGE, rather it has dense irregular connective tissue articular disc.
The articular disc divides the superior and inferior compartments of the TMJ complex. It is important to note that each part is a seperate functional unit with its own specific movements.
What are the movements of the upper and lower compartments of the TMJ complex?
Lower compartment: Is the first movement. It is called the HINGE MOVEMENT (rotational) Results in opening the jaw.
Upper compartment: Is the second movement SLIDING GLIDING MOVEMENT which leads to full opening and protrusion of the mandible.
Note: Before the upper compartment can move the lower compartment must first perform its movement.
What are the 3 segments of the Maxillary artery? What muscle is the reference point for these three segments?
The reference muscle is the Lateral pterygoid
What arteries branch off of the Maxillary artery? Which segment do they belong too?
mneumonic: MIDBIPS
Mandibular Segment
Pterygoid Segment
Ptergopalatine Segment
Where does the mandibular division of the trigeminal nerve exit the middle cranial fossa? Where does it enter
It exits through the foramen ovale and enters the infratemporal fossa