Wk7 - muscles of mastication

Question 1

The masseter has two heads, what are they?

Answer 1

Deep head and superficial head

Question 2

What are the origins of the masseter muscle?

Answer 2

Deep head = zygomatic arch

Superficial head = zygomatic arch and temporal process of the sygomatic bone

Question 3

What are the insertions for the msseter muscle?

Answer 3

Angle of the mandible (superficial head) and ramus of the mandible (superficial and deep heads)

Question 4

What is the nerve supply and blood supply for the masseter muscle?

Answer 4

nerve = masseteric nerve from anterior branch of the mandibular division of the trigeminal nerve

blood = masseteric artery from maxillary artery

Question 5

What is the action of the masseter muscle?

Answer 5

Elevates and protrudes the mandible

Question 6

What is the origin of the temporalis muscle?

Answer 6

Temporal fossa up to the inferior temporal line and temporal fascia

Question 7

What covers both the temporalis and masseter to separate them from other tissues?

Answer 7

Fascia

Question 8

What is the insertion of the temporalis muscle?

Answer 8

Coronoid process and anterior border of the ramus of mandible

Question 9

What are the nerve and blood supplies for the temporalis muscle?

Answer 9

• Nerve supply = mandibular branch of CNV
• Blood supply = deep temporal branches of maxillary artery which branch from maxillary artery

Question 10

What are the 2 functional parts of the temporalis and what is the function of each part?

Answer 10

• Anterior – fibres run vertically and elevate the mandible
  
  • Posterior – fibres run almost horizontally which assists in elevation and retracts mandible (only muscle that can protrude mandible)

Question 11

With relation to the medial pterygoid, where does the lateral pterygoid lie?

Answer 11

Superior to medial pterygoid

Question 12

What are the 2 head of the lateral pterygoid?

Answer 12

Smaller superior head and larger inferior head

Question 13

What is the origin and insertion of the superior head?

Answer 13

Origin = infratemporal crest of the greater wing of the sphenoid bone

Insertion = joint capsule of TML

Question 14

Whar is the origin and insertion of inferior head of lateral pterygoid?

Answer 14

Origin = lateral surface of the lateral pterygoid plate (of sphenoid bone)

Insertion = pterygoid fovea on neck of condyle of mandible

Question 15

What is the nerve and blood supply of the lateral pterygoif?

Answer 15

n - cnV mandibular divison

blood = maxillary artery (pterygoid branch)

Question 16

What are the fucntions of the lateral pterygoid muscle?

Answer 16

Protrusion and depression of the mandible

Side to side movements

Question 17

What are the origins and insertion for the deep head of the medial pterygoid muscle?

Answer 17

origin = medial surface of lateral plate of sphenoid boe

insertion = medial surface of ramus and angle of mandible

Question 18

What is the origin and insertion of the superficial head of the medial pterygoid?

Answer 18

origin = tuberosity of maxilla (just behind 3rd molar)

insertion = medial surface of the ramus and angle of mandible

Question 19

What is the nerve and blood supply of medial pterygoid muscle?

Answer 19

Same as lateral pterygoid

nerve = mandibular branch of trigeminal

blood = pterygoif branch of maxillary artery

Question 20

What are the functions of the medial pterygoid?

Answer 20

elevates and protrudes the mandible

side to side movements