Lecture 2- muscles of mastication

Question 1

How many maxillary bones are present in the skull?

Answer 1

2

Question 2

The 2 maxillary bones are fused together at the:

Answer 2

mid-palatal suture

Question 3

The superior border of the maxilla is the:

Answer 3

floor of the nasal cavity and orbit

Question 4

The inferior border of the maxilla is the:

Answer 4

palate and alveolar ridge

Question 5

Components of the maxilla: (2)

Answer 5

Body & Procresses

Question 6

What processes are fun din the maxilla?

Answer 6

zygomatic, frontal, alveolar, palatine

Question 7

What is the largest and strongest bone of the skull?

Answer 7

mandible

Question 8

What components make up the mandible?

Answer 8

body and ramus

Question 9

The superior aspect of the mandible:

Answer 9

alveolar crest and teeth

Question 10

The body of the mandible makes up the posterior aspect including:

Answer 10

mandibular angle, and asending ramus

Question 11

What two parts make up the ascending ramus?

Answer 11

coronoid process and condyle

Question 12

In the TMJ, the condyle articulates with the:

Answer 12

cranium

Question 13

What poles are present in the condyle?

Answer 13

medial and lateral poles

Question 14

The mediolateral length of the condyle is:

Answer 14

15-20mm

Question 15

The anterior-posterior width of the condyle is:

Answer 15

8-10mm

Question 16

The squamous portion of the temporal bone articulates with the:

Answer 16

mandibular condyle

Question 17

The _____ articulates with the mandibular condyle

Answer 17

Squamous portion of temporal bone

Question 18

The thick dense bone to tolerate heavy forces (on temporal bone)

Answer 18

articular eminence

Question 19

What are the muscles of mastication?

Answer 19

lateral pterygoids, medial pterygoid, masseter and temporalis

Question 20

The masseter has ___ heads

Answer 20

2

Question 21

The two heads of the masseter:

Answer 21

superficial head and deep head

Question 22

In the ____ head of the masseter, fibers run downward and backward

Answer 22

superficial

Question 23

In the ____ head of the masseter, the fibers run in a vertical direction

Answer 23

deep

Question 24

How do the muscle fibers run in the superficial head of the masseter?

Answer 24

fibers run downward and backward

Question 25

How do the fibers run in the deep head of the masseter?

Answer 25

fibers run in a vertical direction

Question 26

Where is the origin of the masseter?

Answer 26

zygomatic arch

Question 27

Where is the insertion of the masseter? (2)

Answer 27

lateral surface of ramus and angle of mandible

Question 28

Function of the masseter:

Answer 28

elevate the mandible

Question 29

The masseter is a ____ muscle providing the force for ____.

Answer 29

powerful; chewing

Question 30

Portion of the masseter that aids in protrusion:

Answer 30

superficial head

Question 31

Function of the superficial head of the masseter:

Answer 31

aids in protrusion

Question 32

Portion of the masseter that stabilizes the condyle against the eminence

Answer 32

deep head

Question 33

Function of the deep head of the masseter:

Answer 33

stabilzes the condyle against the eminence

Question 34

The origin of the superficial portion of the masseter: The origin of the deep portion of the masseter:

Answer 34

anterior 2/3 of lower border of zygomatic arch medial surface of the zygomatic arch

Question 35

The insertion of the masseter is the:

Answer 35

lateral surface of ramus coronoid process and angle of mandible

Question 36

The function of the masseter is to:

Answer 36

elevate jaw and clench teeth

Question 37

The blood supply to the masseter:

Answer 37

a muscular branch of the maxillary artery

Question 38

The nerve supply to the masseter:

Answer 38

masseteric nerve of mandibular division of the trigeminal nerve

Question 39

The temporalis can be divided into ____ distinct divisions:

Answer 39

3

Question 40

The 3 distinct divisions of the temporalis include:

Answer 40

anterior, middle, posterior

Question 41

Portion of the temporalis characterized by the vertically directed fibers

Answer 41

anterior

Question 42

Portion of the temporalis characterized by fibers running obliquely across the lateral aspect of the skull

Answer 42

middle

Question 43

Portion of the temporalis characterized by horizontal fibers coming forward above the ear to join other temporalis fibers

Answer 43

posterior

Question 44

Origin of the temporalis:

Answer 44

termporal fossa and lateral surface of the skull

Question 45

Insertion of the temporalis: (2)

Answer 45

coronoid process and anterior border of ascending ramus

Question 46

Action of the anterior temporalis:

Answer 46

vertical raising of mandible

Question 47

Action of the middle temporalis:

Answer 47

elevates and retrudes the mandible

Question 48

action of the posterior temporalis:

Answer 48

aids in recursion of the mandible

Question 49

Blood supply to the temporalis:

Answer 49

a muscular branch of the maxillary artery

Question 50

Nerve supply to termporalis:

Answer 50

deep temporal nerve of the mandibular division of trigeminal nerve

Question 51

How many heads are present in the lateral pterygoid?

Answer 51

2

Question 52

The lateral pterygoid may also be referred to as:

Answer 52

external pterygoid

Question 53

The two heads of the lateral pterygoid are almost:

Answer 53

almost two separate muscles

Question 54

What are the two heads of the lateral pterygoid?

Answer 54

superior lateral pterygoid and inferior lateral pterygoid

Question 55

The origin of the inferior lateral pterygoid:

Answer 55

outer surface of lateral pterygoid plate

Question 56

The insertion of the inferior lateral pterygoid:

Answer 56

neck of condyle

Question 57

The inferior lateral pterygoid extends:

Answer 57

backward, upward, and outward

Question 58

The action of the inferior lateral pterygoid includes both:

Answer 58

bilateral contraction and unilateral contraction

Question 59

"causes the condyles to be pulled down and the articular eminences and the mandible is protruded" would be describing what action of the inferior lateral pterygoid?

Answer 59

bilateral contraction

Question 60

"causes mediotrusive movement (downward, forward, and medially)" would be describing what action of the inferior lateral pterygoid?

Answer 60

unilateral contraction

Question 61

Which is the smallest of the 2 bellies of the lateral pterygoids?

Answer 61

superior lateral pterygoid

Question 62

The origin of the lateral pterygoid:

Answer 62

infratemporal surface of the greater sphenoid wing

Question 63

The insertion of the superior lateral pterygoid:

Answer 63

disk, capsule, and neck of the condyle

Question 64

The superior lateral pterygoid action is ____ during mandibular opening

Answer 64

inactive

Question 65

The superior lateral pterygoid is active only with:

Answer 65

elevator muscles

Question 66

The superior lateral pterygoid is active only with elevator muscles - meaning

Answer 66

closure of the mandible

Question 67

The superior lateral pterygoid is involved in a ______: this muscle is active during mandibular closure against resistance (chewing or clenching)

Answer 67

power stroke

Question 68

Muscle involved in the power stroke

Answer 68

superior lateral pterygoid

Question 69

The superior lateral pterygoid is active during:

Answer 69

mandibular closure against resistance (chewing or clenching)

Question 70

mandibular closure against resistance=

Answer 70

chewing or clenching

Question 71

blood supply to lateral pterygoid:

Answer 71

a muscular branch of the maxillary artery

Question 72

nerve supply to lateral pterygoid:

Answer 72

a branch of the masseteric or buccal nerve of the mandibular division of the trigeminal nerve

Question 73

Origin of the medial (internal) pterygoid:

Answer 73

pterygoid fossa

Question 74

What is another name for the medial pterygoid?

Answer 74

internal pterygoid

Question 75

The insertion of the medial (internal) pterygoid:

Answer 75

medial surface of the mandibular angle

Question 76

What are the 3 functions of the medial (internal) pterygoid:

Answer 76

1. elevates the mandible 2. protrudes the mandible 3. unilateral contraction (results in mediotrusion)

Question 77

The unilateral contraction function of the medial pterygoid results in:

Answer 77

mediotrusion