Muscles of Mastication Flashcards
What are the 4 muscles of mastication?
- Temporalis
- Masseter
- Medial pterygoid
- Lateral pterygoid
What are the 4 movements of the jaw?
- Protrusion
- Retrusion
- Elevation
- Depression
What is the origin of the masseter?
Zygomatic arch
What is the insertion of the masseter?
Ramus and angle of mandible
What is the nerve supply of the masseter?
Masseteric from ant. division of mandibular nerve
What are the 2 actions of the masseter?
- Elevation of mandible
2. Protrusion of mandible
What are the 3 origins of the temporalis?
- Temporal lines
- Temporal fossa
- Deep surface of temporal fascia
What is the insertion of the temporalis?
Coronoid process
What is the nerve supply of the temporalis?
Deep temporal nerve from ant. division of mandibular nerve
What is the action of the ant. fibres of the temporalis?
Elevation of mandible
What is the action of the post. fibres of the temporalis?
Retrusion of the mandible
What is the origin of the upper head of the lateral pterygoid?
Infratemporal surface of greater wing of sphenoid
What is the origin of the lower head of the lateral pterygoid?
Lateral surface of lateral pterygoid plate
What is the insertion of the upper head of the lateral pterygoid?
Join capsule and intraarticular disc
What is the insertion of the lower head of the lateral pterygoid?
Neck of the mandible (pterygoid fovea)
What is the nerve supply of the lateral pterygoid?
Ant. division of mandibular nerve
What is the bilateral action of the lateral pterygoid?
Depression of the mouth
What is the unilateral action of the lateral pterygoid?
Side to side movement of mandible
What is the origin of the superficial head of the medial pterygoid?
Maxillary tuberosity
What is the origin of the deep head of the medial pterygoid?
Medial surface of lateral pterygoid plate
What is the insertion of the medial pterygoid?
Deep surface of ramus and angle of mandible
What is the nerve supply of the medial pterygoid?
Trunk of the mandibular nerve
What is the bilateral action of the medial pterygoid?
Elevation of mandible
What is the unilateral action of the medial pterygoid?
Side to side movement of mandible
What muscles of mastication cause the mandible to protract?
- Lateral pterygoid
2. Masseter
What muscles of mastication cause the mandible to retract?
- Posterior fibres of temporalis
What muscles of mastication cause the mandible to elevate?
- Masseter
- Medial pterygoid
- Anterior fibres of temporalis
What muscles of mastication cause the mandible to depress?
Lateral pterygoid
