muscles of mastication

Question 1

Masseter

Answer 1

O:Zygomatic arch, maxillary process of the zygomatic bone
I: Lateral surface of ramus of Mandible
N: Masseteric nerve from the anterior trunk of the mandibular nerve
A: Elevation of mandible

Question 2

Temporalis

Answer 2

O:Bone of temporal fossa and temporal fascia
I:Coronoid process of mandible, anterior margin of ramus of mandible
N: Deep temporal nerves from the anterior trunk of the mandibular nerve
A: Elevation and retraction of mandible

Question 3

Medial Pterygoid

Answer 3

O: (a) medial surface of the lateral pterygoid plate (b) maxillary tuberosity
I: Medial surface of ramus of mandible
N: Nerve to medial pterygoid from the mandibular nerve
A: Elevation and ‘side-to-side’ movements of the mandible

Question 4

Lateral pterygoid

Answer 4

O: (a) infratemporal surface and crest of the greater wing of the sphenoid
(b) lateral surface of the lateral pterygoid plate
I: joint capsule and disc of TMJ, pterygoid fovea on the neck of the mandible
N: Nerve to lateral pterygoid directly from the anterior trunk of the mandibular nerve
A: Protrusion,depression and ‘side-to-side’ movements of the mandible

Question 5

Muscles of mastication

Answer 5

• All supplied by the branches of the mandibular division of trigeminal
• All located in the temporal and infratemporal fossae
• All develop from the mesoderm of the first pharyngeal arch