2. Mastication Flashcards
Masseter
Location
Origin
Insertion
Action
L- powerful muscle that covers lateral aspect of ramps of mandible
O - zygomatic arch and zygomatic bone
I - angle and ramus of mandible
A - closes jaw; elevates mandible
Temporalis
Location
Origin
Insertion
Action
L - fan shapes muscle that covers parts of the temporal, frontal, and parietal bone
O- temporal fossa
I- coronoid process of mandible via a tendon that passes deep to zygomatic arch
A- closes jaw; elevates and retracts mandible; maintains position of the mandible at rest; deep anterior part may help protract mandible
Pterygoid muscle - lateral
Location
Action
L- deep two headed muscle; lies superior to medial pterygoid muscle
A- protracts mandible and produces side to side grinding movements of the lower teeth
Pterygoid muscle - medial
Location
Action
L- deep two headed muscle that runs along internal surface of mandible and is largely concealed by that bone
A- acts w/lateral pterygoid muscle to protract mandible and to produce side to side (grinding) movement; synergist of temporalis and masseter muscles in elevation of the mandible
