Test 2 Questions Flashcards
Where does the temporalis insert into?
Coronoid Process of Mandible
Compared to a human, a gorilla has a bite force that is 9x stronger. Explain why.
Gorillas have a larger temporal fossa that can accomodate a temporalis muscle with a greater cross sectional area; resulting in stronger bite force.
Where does the temporalis originate?
Temporal fossa floor and temporalis fascia
Specifically originates at inferior temporal line.
Superior temporal line is for faschia attachement
Where does the Masseter originate?
Lower border and internal zygomatic arch
Where does the masseter insert?
Lateral ramus of mandible
What’s the most powerful muscle of mastication?
Temporalis
What is the function of masseter?
Elevation of mandible, deep fibers may cause mandibular retraction
How many heads does the lateral pterygoid have?
2 heads
1 Superior, 1 Inferior
Where does the lateral pterygoid superior head insert into? Originate from?
Insert into anterior portion of intra-articular disk through the lateral pterygoid
Originates on infratemporal surface of sphenoid
Where does the lateral pterygoid inferior head insert into? Originate from?
Insert into pterygoid fossa (fovea) of mandibular condyle
Functions of lateral pterygoid?
Mandible protrusion, depression, lateral deviation (1 muscle)
Where does the medial pterygoid originate and insert?
Superficial head originates from maxillary tuberosity and palatine bone
Deep head originates from lateral pterygoid plate of sphenoid
Both heads insert into medial ramus and angle of mandible
How many heads does the medial pterygoid have?
2
1 deep, 1 superficial
Functions of medial pterygoid?
Mandible elevation, protraction, and laterial deviation
What muscles make up the muscular sling
Masseter and “ipsilateral” medial pterygoid
What is significant about the muscular sling?
It supports the mandible on the cranium
How many bellies does the digastric muscle have?
2
1 anterior, 1 posterior
Where does the anterior and posterior bellies of the digastric originate and insert to?
Anterior belly originates at digastric fossa on mandible
Posterior belly originates on mastoid process (mastoid notch of temporal bone)
both muscles unite and form a tendon/tendinous loop and inserts into hyoid bone.
What does the digastric muscle do?
Depression and Retraction of mandible
Stabilization and elevation of hyoid
What does the mylohyoid muscle do?
Elevates floor of mouth and depresses mandible
What innervates the the muscles of mastication? What is the exception?
Mandibular Division of Trigeminal nerve (CNV3)
Exception is posterior belly of digastric. PB of digastric is innervated by facial nerve
What are the boundaries of the temporal fossa? What bones make up the temporal fossa?
Zygomatic process, zygomatic arch, Temporal lines,
Frontal, Parietal, temporal, and sphenoid bones
What are the boundaries of the infratemporal fossa?
Lateral pterygoid plate
Maxilla, Mandibular ramus, Greater wing of sphenoid, Posterior wall (carotid sheath and styloid)
What openings are in the infratemporal fossa?
Foraman Ovale
Foraman Spinosum
Pterygomaxillary fissue
