Oral Physiology

Question 1

Which muscle forms the body of the tongue?

Answer 1

Genioglossus

Question 2

What are the five jaw opener muscles?

Answer 2

1. Digastric
2. Hyoideus
3. Lateral Pterygoid
4. Geniohyoid
5. Mylohyoid

Question 3

Which jaw opener acts as a protractor?

Answer 3

Lateral pterygoid

Question 4

Dysfunction of the superior head of which muscle is associated with anterior displacement of TM disc in TMJ dysfunction?

Answer 4

Lateral pterygoid

Question 5

What are the two parts of the masseter?

Answer 5

Deep and superficial

Question 6

What fibers are predominant in the masseter?

Answer 6

Slow fibers

Question 7

What might be a reason you find alpha cardiac muscle fibers in the masseter?

Answer 7

Rhythmic contraction involved with chewing

Question 8

T/F: The masseter is mostly slow fibers, however there are more fast fibers found toward the posterior portion of the muscle.

Answer 8

TRUE

Question 9

What is bruxism?

Answer 9

Hypertrophy in the masseter leading to an upregulation of slow myosin

Question 10

T/F: The temporalis is slower than the masseter?

Answer 10

FALSE

Question 11

T/F: The temporalis has slower fibers anteriorly, and faster fibers posteriorly.

Answer 11

TRUE

Question 12

Most jaw closing muscles are predominantly ____ fibers while most jaw openers are predominantly ____ fibers.

Answer 12

Slow; fast

Question 13

In jaw closers, more slow fibers found in _____ and _____.

Answer 13

Deep; anterior

Question 14

What is kinesthesia?

Answer 14

Sense of movement and position

Question 15

T/F: The masticatory muscles are under extreme “surveillance” from sensory nerves in the muscles.

Answer 15

TRUE

Question 16

What is the job of muscle spindles?

Answer 16

Detect the length of the muscle

Question 17

T/F: Muscle spindles are thicker than a typical muscle fiber.

Answer 17

TRUE

Question 18

T/F: Muscle spindles are found perpendicular to muscle fibers.

Answer 18

FALSE

Parallel

Question 19

_______ fibers do the work on a muscle, while ________ fibers are found in the muscle spindle.

Answer 19

Extrafusal; intrafusal

Question 20

Gamma fibers are the most common ________ fibers found in the muscle spindle.

Answer 20

Efferent

Question 21

T/F: Muscle spindles are full of lymph.

Answer 21

TRUE

Question 22

What are the two types of sensory nerve fibers in a muscle spindle?

Answer 22

Ia (primary): better at detecting short term change in length

II (secondary): better at detecting long term positions of length

Question 23

What is the role of gamma fibers in the muscle spindle?

Answer 23

After CNS knows muscle has shortened -> CNS uses gamma fibers to contract polar regions -> stretches equatorial region to resensitize the spindle

Question 24

T/F: Afferent activity decreases as a muscle shortens.

Answer 24

TRUE

Question 25

Where are golgi tendon organs found?

Answer 25

In junction between ends of muscle fibers at the tendon

Question 26

What is the function of golgi tendon organs?

Answer 26

Generate signals proportional to the amount of force generated by extrafusal muscle fibers

Question 27

Control and coordination of mastication is from the ____.

Answer 27

CNS

Question 28

What are the four phases of the chewing cycle?

Answer 28

1. Slow opening 2. Fast opening 3. Fast closing 4. Slow closing

Question 29

What are the three masticatory phases?

Answer 29

1. Preparatory: tongue, lips, buccinator, etc. (most variable for different types of food) 2. Reduction: food breakdown 3. Pre-swallowing: bolus formation

Question 30

T/F: Herbivores have no masticatory myosin.

Answer 30

TRUE

Question 31

Herbivores have a larger _______ muscle, while carnivores have a larger _______ muscle.

Answer 31

Masseter; temporalis

Question 32

How can electromyography be used to diagnose clinical situations?

Answer 32

Look at muscle activity and compare to normal individuals

Question 33

T/F: The whole process of swallowing is a voluntary process.

Answer 33

FALSE Can be voluntary, however at a certain point it becomes a reflex (cannot stop it)

Question 34

What are the four components involved with swallowing?

Answer 34

1. Brain stem 2. Six cranial nerves 3. Receptors 4. Muscles

Question 35

The preparatory phase of swallowing is the same as what phase of mastication?

Answer 35

Pre-swallowing: forming the bolus

Question 36

What physiological structure is formed during the preparatory phase?

Answer 36

Glossopalatal sphincter

Question 37

What is the second phase of swallowing?

Answer 37

Oral phase: bolus moves from oral cavity to pharynx

Question 38

During the oral phase, the _____ ______ is formed when the lips close and the lower incisors move close together.

Answer 38

Oral seal

Question 39

Describe the actions that allow the bolus to move into the sphincter.

Answer 39

Glossopalatal sphincter formed by tongue and soft palate -> anterior tongue pushes against hard palate -> base of tongue moves down and forward while palate moves up (opens glossopalatal sphincter -> palate shuts off nasal cavity

Question 40

What is the third phase of swallowing?

Answer 40

Pharyngeal phase: movement of bolus from oropharynx to esophagus

Question 41

T/F: The epiglottis is required to prevent aspiration of food.

Answer 41

FALSE

Question 42

The _________ group of muscles is involved in the oral and prep phases of swallowing.

Answer 42

Facultative

Question 43

The ________ group of muscles are involved in the pharyngeal phase of swallowing.

Answer 43

Obligate

Question 44

T/F: The upper esophageal sphincter remains open for multiple swallowing events.

Answer 44

FALSE Opens and closes for each swallow. Lower esophageal sphincter can remain open

Question 45

What mechanisms prevent aspiration of food?

Answer 45

1. Inhibited respiration 2. Larynx and upper esophageal sphincter elevate 3. Vocal cords close 4. Bolus moves through sinuses in pharynx

Question 46

Which phases of swallowing are involuntary?

Answer 46

Pharyngeal and esophageal phases

Question 47

What are the three components of the swallowing center of the brain stem?

Answer 47

1. Sensory nuclei 2. Interneuronal network nuclei 3. Motor nuclei

Question 48

What is the function of the interneuronal network of the swallowing center?

Answer 48

Mediate interaction between motor and sensory nuclei

Question 49

Where is the interneuronal network found?

Answer 49

Ventral and dorsal medulla

Question 50

________ interneurons initiate and program the timing of swallowing.

Answer 50

Dorsal

Question 51

_______ interneurons distribute the excitation to the swallowing motor nuclei.

Answer 51

Ventral

Question 52

Where is afferent information sent during swallowing?

Answer 52

NTS

Question 53

T/F: The preparatory and oral phases of swallowing are programmed in utero.

Answer 53

FALSE Obligate muscles are programmed in utero

Question 54

Which muscles do not have a prominent role in swallowing before tooth eruption?

Answer 54

Jaw closers

Question 55

T/F: Infants can swallow without disrupting respiration.

Answer 55

FALSE

Question 56

Which muscles play a prominent role in infant suckling, but do not play a role in adult sucking?

Answer 56

Jaw opening and closing muscles

Question 57

What is emesis?

Answer 57

Vomiting

Question 58

What are the two types of stimuli that can cause emesis?

Answer 58

1. Physiological: pain, imbalance, substance in blood | 2. Disease-related stimuli: increased intracranial pressure, radiation, anesthesia, stress

Question 59

What is the first phase of vomiting?

Answer 59

Pre-ejection: licking, salivation, increased heart rate, relaxation of proximal part of stomach

Question 60

T/F: The pre-ejection phase of vomiting can last several days.

Answer 60

TRUE pregnancy

Question 61

The ejection portion of vomiting involves what two phases?

Answer 61

1. Retching | 2. Expulsion

Question 62

Describe the pressure gradients in the retching and expulsion phases?

Answer 62

1. Retching: decrease in intra-thoracic pressure, increase in intra-abdominal pressure 2. Expulsion: Intra-thoracic and intracellular-abdominal pressure increase tremendously

Question 63

What part of the brainstem controls the vomiting cycle?

Answer 63

Medulla

Question 64

Why is interferences in occlusion not likely to cause bruxism?

Answer 64

Primary effect of tooth stimulation is inhibition of jaw-closers

Question 65

What are the two major issues of TMDs?

Answer 65

1. Pain | 2. Impaired chewing efficiency

Question 66

T/F: TMD is more common in women than men.

Answer 66

TRUE

Question 67

What disease could have a link to TMDs?

Answer 67

Fibromyalgia

Question 68

Stimulation of the _______ results in stress-like responses and excitation of jaw-closer motorneurons.

Answer 68

Hypothalamus