Physiology of Mastication and Deglutition Part 2

Question 1

Mastication and Deglutition Reflexes

Answer 1

-Mediated in brainstem
-Posterior brainstem: reticular formation

Question 2

Chewing Center Reflexes

Answer 2

-Located in pons and caudal reticular formation

Question 3

Chewing Center Reflexes Controls

Answer 3

-Mastication
-Tongue Movement: bolus generation and
move tongue on/off molars
-sucking
-licking

Question 4

Sucking

Answer 4

-natural involuntary newborn reflex: initiate sucking when mouth or roof of mouth touched
-essential for feeding and developing coordination with breathing and swallowing

Question 5

Rooting

Answer 5

-natural involuntary newborn reflex helps babies find and latch onto nipple to feed
-triggered by touching or stroking cheek or mouth
-producing head turn and open mouth: searching for food source
-perioral tactile stimulation mediated: V CN (Trigeminal)

Question 6

Uvular (Palatal) Reflex

Answer 6

-Tactile sensors to uvula, fauces, or soft palate
-Cause velum to elevate
-Mediated: IX CN (glossopharyngeal)

Question 7

Gag (Pharyngeal) Reflex

Answer 7

-Tactile stimulation of faucial pillars, posterior pharyngeal wall, or posterior tongue near lingual tonsils: can be elicited by taste
-Response: laryngeal elevation, vocal folds clamping, velum closes, abdominal muscles contract
-mediated: IX CN (glossopharyngeal)

Question 8

Retch Reflex

Answer 8

-Involuntary attempt at vomiting
-can be caused by distressing visual or mental stimulation
-Retching center near swallow center in reticular formation

Question 9

Retch Reflex Noxious Smells

Answer 9

-Noxious smells: CN I Olfactory

Question 10

Retch Reflex Tastes

Answer 10

-Tastes: CN IX Glossopharyngeal

Question 11

Retch Reflex GI Stress

Answer 11

-GI Stress: CN X Vagus

Question 12

Retch Reflex Vestibular Dysfunction

Answer 12

-Vestibular Dysfunction: CN VII Vestibulocochlear

Question 13

Vomit Reflex

Answer 13

-oral expulsion of GI contents
-includes multiple simultaneous and/or synchronous reflexes

Question 14

Vomit Reflex Steps

Answer 14

-occlusion of airway: vocal folds adduct
-extreme contraction of abdominal walls
-relaxation of UES and LES
-Elevation of larynx and velum
-Depression of epiglottis
-Elevation of pharynx
-Tongue protrusion

Question 15

Cough Reflex Initiated by

Answer 15

noxious stimulation of pharynx, larynx, or bronchial passageway

Question 16

Cough Reflex CN X Vagus Nerve

Answer 16

CN X Vagus afferent transmits stimulation information to nucleus solitarius of medulla

Question 17

Cough Reflex Interneurons

Answer 17

-Interneurons activate expiration center of reticular formation: causes abdominal muscles to contract

Question 18

Cough Reflex Nucleus Ambiguous

Answer 18

-Nucleus ambiguous (motor nucleus of X CN [Vagus] causes laryngeal adduction prior to exhalation: produces subglottal pressure build up to dislodge irritant from airway

Question 19

Gustation

Answer 19

-act or sensation of tasting
-fundamental sense helps identify and select foods

Question 20

Basic Tastes Humans Can Perceive

Answer 20

-sweet
-salty
-sour
-bitter
-umami (savory)

Question 21

Function of Gustation

Answer 21

-helps determine if something is nutritious, delicious, or potentially harmful
-allows us to choose what to eat or avoid

Question 22

Gustation Mechanism

Answer 22

-mediated by taste buds located primarily on tongue
-contain specialized receptor cells detect different taste stimuli and transmit signals to brain

Question 23

Gustation: Interaction w/other senses

Answer 23

-smell and trigeminal nerve stimulation
-registers texture, pain, temp
-create overall flavor experience

Question 24

Gustation: Central Processing

Answer 24

-travels along cranial nerves to brainstem
-then thalamus
-finally gustatory cortex: taste processed and consciously perceived

Question 25

Taste Buds or Cells

Answer 25

-Class of sensors called chemoreceptors: neural receptors respond to specific chemicals -Located in epithelia of tongue within papillae

Question 26

Taste Maps: Sweet, starchiness, umami

Answer 26

-anterior tongue

Question 27

Taste Maps: Bitter

Answer 27

-posterior tongue

Question 28

Taste Maps: Salty

Answer 28

-front sides of tongue

Question 29

Taste Maps: Sour

Answer 29

-back sides of tongue

Question 30

Taste Maps: Whole Tongue

Answer 30

-whole tongue perceives all tastes -no taste map

Question 31

Transmission of Tastes: CN VII (Facial)

Answer 31

-tongue anterior 2/3 -palate receptors -sweet, salty, sour

Question 32

Transmission of Tastes: CN XI (Glossopharyngeal)

Answer 32

-tongue posterior 1/3

Question 33

Transmission of Tastes: CN X (Vagus)

Answer 33

-epiglottis and esophagus receptors

Question 34

Transmission of Tastes: CN V (Trigeminal)

Answer 34

-chemistetics: detection of chemical stimuli by heat or pain

Question 35

Aging Taste Changes

Answer 35

-intensity of taste and smell reduced: smell mostly -causes loss of interest in food -can add taste supplements: caution too much salt -some medications give metallic taste or other unpleasant taste

Question 36

Medications Effecting Taste

Answer 36

-tetracycline: antibiotic -lithium carbonate: antipsychotic -penicillamine: antiarthritic -captopril: antihypertensive

Question 37

Glandular Secretion: Parotid Glands

Answer 37

-posterior, under masseter -secretes serous saliva (slippery) -helps move bolus

Question 38

Glandular Secretion: Sublingual Glands

Answer 38

-under anterior tongue -secretes mucoidal (dense) saliva -helps organize bolus

Question 39

Glandular Secretion: Submandibular Glands

Answer 39

-secretes combo of serous and mucoidal saliva

Question 40

Parotid Glands

Answer 40

-Innervated by CN IX (Glossopharyngeal) -secretes serous saliva -thin and slippery -helps move bolus down pharynx

Question 41

Sublingual Glands

Answer 41

-Innervated by CN VII (Facial) -secrete mucoidal saliva -thick -binds bolus into unit

Question 42

Submandibular Glands

Answer 42

-Innervated by CN VII (Facial) -secretes combo mucoidal and serous saliva