mastication muscles

Question 1

Temporalis muscle :

Answer 1

origin: Inferior temporal line, temporal fossa.

insertion: Into coronoid process.

nerve supply: Anterior division of mandibular nerve.

action: Elevation & refraction of mandible.

Question 2

Masseter muscle :

Answer 2

origin: Superficial fibers are from lower border of zygomatic arch, Deep fibers are from deep surfaces of zygomatic arch.

insertion: Lateral surface of mandible ramus.

nerve supply: Anterior division of mandibular nerve.

action: Elevation & protraction of mandible.

Question 3

Lateral pterygoid :

Answer 3

origin: Upper head is from infra-temporal surface of greater wing of sphenoid, Lower head is from lateral surface of lateral pterygoid plate.

insertion: Capsule & articular disc of TMJ, pterygoid fossa of the neck of mandible.

nerve supply: Anterior division of mandibular nerve.

action: Depress mandible & both muscles protrude the mandible.

Question 4

Medial pterygoid :

Answer 4

origin: Superficial head is from maxillary tuberosity, Deep head is from medial surface of lateral pterygoid plate.

insertion: Medial surface of angle of mandible.

Nerve supply: Main trunk of mandibular nerve.

action: Elevate mandible & both muscles protrude mandible.