1E Mastication

Question 1

All muscles of mastication are innerated by which nerve?

Answer 1

V3 branch of the trigeminal

Question 2

What are the muscles of mastication?

Answer 2

MTML - masseter, temporalis, medial pterygoid, and lateral pterygoid

Question 3

What is the action of the masseter?

Answer 3

Elevates mandible

Question 4

What is the action of the temporalis?

Answer 4

Elevates mandible; retracts mandible

Question 5

What is the action of the lateral pterygoid?

Answer 5

Draws condyle and disk forward. Protrudes (acting together). Grinding action (acting alternately)

Question 6

What is the action of the medial pterygoid?

Answer 6

Elevates mandible; Protrudes mandible(acting together). Grinding action (acting alternately). Protrudes one side (acting alone)

Question 7

What muscle of mastication generates the most force?

Answer 7

Masseter

Question 8

What is the function of mastication?

Answer 8

Mechanical breakdown of food; chemical breakdown by mixing ingested material w/ saliva

Question 9

What is the end result of mastication?

Answer 9

Production of a bolus that can be swallowed

Question 10

What are the three phases of the masticatory cycle?

Answer 10

Opening - relaxation of jaw elevators; contraction of jaw openers.
Closing - jaw elevates and turns to working side
Occlusal - jaw nears closure; strongest forces are exerted; represents the longest component of the cycle

Question 11

Which muscles are involved in protrusion?

Answer 11

Lateral and medial pterygoids

Question 12

Which muscles are involved in retraction?

Answer 12

Posterior temporalis, deep masseter, and geniohyoid and digastric

Question 13

Which muscles are involved in elevation?

Answer 13

Temporalis, masseter, and medial pterygoid (ALL but lateral pterygoid)

Question 14

Which muscles are involved in depression?

Answer 14

Digastric, geniohyoid, and mylohyoid