Muscles of Mastication Flashcards
what are the 4 muscles involved in mastication?
- temporalis muscle
- masseter muscle
- medial pterygoid
- lateral pterygoid
what are all the muscles of mastication innervated by?
mandibular nerve
what is the origin and insertion of the massester?
origin - superficial (maxillary process of zygomatic bone); deep (zygomatic arch of temoral bone)
insertion - ramus of mandible
what is the action of the masseter?
elevate the mandible
what is the origin and insertion of the temporalis muscle?
- origin - temporal fossa and parietal bone
- insertion - coronoid process of mandible
what is the action of the temporalis?
- anterior fibres elevate mandible
- posterior fibres retract mandible
the lateral pterygoid has two heads - what are they?
superior and inferior heads
the medial pterygoid has two heads - what are they?
deep and superficial heads
what is the origin and insertion of the superior head of the lateral pterygoid?
- origin - infratemporal surface + greater wing of sphenoid
- insertion - pterygoid fovea of mandible
what is the origin and insertion of the inferior head of the lateral pterygoid?
- origin - lateral pterygoid plate of sphenoid
- insertion - pterygoid fovea of the mandible
what are the actions of the lateral pterygoid?
- bilateral contractions - push mandible forward
- unilateral contractions - frictional masticatory movements
what is the origin and insertion of the deep head of the medial pterygoid?
- origin - medial aspect of lateral pterygoid plate of sphenoid bone
- insertion - pterygoid tuberosity of mandible
what are the origins and insertions of the superficial head of the medial pterygoid?
- origin - maxillary tuberosity
- insertion - pterygoid tuberosity of the mandible
what are the actions of the medial pterygoid?
- bilateral contraction - elevates mandible
- unilateral contraction - frictional “grinding” masticatory movements
label these two muscles
label the pterygoids
