Muscles of mastication Flashcards
Attached to the more moveable structure
Insertion
Movement accomplished by muscle contraction
Action
Process of mastication
Ingestion of food,
Muscles coordinate to place food between opposing teeth
Under control of nervous system
T or F
Muscles of mastication are all paired..
True
Masseter origins:
Superficial and Deep
Superficial-anterior 2/3s inferior zygoma
Deep-posterior 1/3s medial of zygoma
Masseters insertions:
Superficial and Deep
Sup- lower 1/2 of external surface of Ramus, angle of mandible.
Deep- lower 1/2 of external Ramus.
Masseter action
Elevation of the mandible, raises jaw, closes mouth
Masseter hypertrophy-
Increase in the cellular volume
Cells get bigger, bigger jaw.
Unilaterally and bilaterally
Temporalis origin
Temporal Fossa
Temporalis insertion
Coronoid process of mandible
Starts at temporal fossa and runs medically by zygomatic arch.
Temporalis action
Elevation of mandible
Posterior fibers: retrusion of mandible
Note: not a strong muscle
Temporalis muscle shape:
Fan shaped.
Runs medial by zygoma arch.
Medial pterygoid origin
Medial of lateral pterygoid plate
Medial pterygoid insertion
Medial portion of mandibular angle
Medial pterygoid action
Elevation of muscles,
Elevate and closes mouth
With action of masseter, creates a “supportive sling” for mandible
Medial pterygoid
Lateral pterygoid origins
Lateral of lateral pterygoid plate
Sphenoid greater wing
Lateral pterygoid insertions
Anterior of condyle neck
*Some fibers to TMJ capsule
Lateral pterygoid actions
Slight depression of mandible,
Protrusion of mandible,
Shifting of mandible (side to side)
Origin
Attached to the least moveable structure
Muscles of mastication blood supply
Branches of the maxillary artery
