axial muscles - origins and insertions for muscles of mastication Flashcards
origin of the buccinator
- alveolar processes of maxilla and mandible
- pterygomandibular raphe
insertion of the buccinator
- bends into fibers of orbicularis oris
what is the upper and lower attachment of the pterygomandibular raphe
upper: pterygoid hamulus
lower: mandible, immediatley posterior to the third molar
is the buccinator a muscle of mastication
no
what are the muscles of mastication
- temporalis
- masseter
- medial pterygoid
- lateral pterygoid
how is the lateral pterygoid divided
- superior and inferior
what are the origins of the lateral pterygoid
superior:
- lateral surface of greater wing of sphenoid
inferior
- lateral surface of the lateral pterygoid plate
what is the insertion for the lateral pterygoid
superior
- articular disc
- capsule of TMJ
inferior
- superiormedial surface of the ramus of the mandible
- condylar process of mandible
what are the actions of the lateral pterygoid
bilateral
- protrudes mandible, pulls articular disk forward
- depresses mandible
unilateral
- lateral movements of chewing (mandible)
how is the medial pterygoid divided
superficial and deep
what is the origin of the medial pterygoid
superficial
- maxillary tuberosity of the maxilla
deep
- medial surface of lateral pterygoid plate
- lateral surface of medial pterygoid plate
- pterygoid fossa
what is the insertion of the medial pterygoid
- medial surface of ramus
- angle of mandible
what are the actions of the medial pterygoid
- elevates mandible
- protrudes mandible
- unilateral (lateral movements of chewing)
what is the deepest muscle of mastication
medial pterygoid
what are the portions of the temporalis, and what fibers are associated with each
- anterior portion: vertical fibers
- middle portion: oblique fibers
- posterior portion: horizontal fibers
what is the origin of the temporalis
- inferior temporal line of the temporal fossa
- temporal fascia
what is the insertion of the temporalis
- coronoid process of mandible
- anterior border of the ramus of the mandible
- **travels under the zygomatic arch
what are the actions of the temporalis
- vertical/anterior fibers: elevate mandible
- middle/oblique and posterior/horizontal fibers: retrude mandible
- unilateral: lateral movement of chewing (mandible)
how is the masseter divided
- superficial and deep head
how do the fibers run in the portions of the masseter
- superficial: downward and slightly bakward
- deep: fibers run vertically
what is the origin for the masseter
superficial
- anterior 2/3 of the zygomatic arch
deep
- posterior 1/3 of the zygomatic arch
what is the insertion of the masseter
superficial
- mandibular angle and ramus
deep
- mandibular ramus and coronoid process
what are the actions of the masseter
- elevate mandible (teeth brought into contact)
- protrude mandible (superficial head)
- unilateral (lateral movement of mandible or chewing)
