mastication and deglutition i
TRANSCRIPT
![Page 1: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/1.jpg)
Mastication and Deglutition-I
•Swallowing becomes a great concern for the elderly, mainly due to strokes and Alzheimer's disease.•It has been reported that 25%-45% of typically developing children demonstrate feeding and swallowing problems•Prevalence is estimated to be 30%-80% for children with developmental disorders•Each year, approximately one in 25 adults will experience a swallowing problem in the United States •Swallowing problems are more common among older individuals•A patient with dysphagia is unable to consume sufficient calories and nutrients to maintain health.
Prof. Dr. Rashid Mahmood
![Page 2: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/2.jpg)
2
Movements of GITIngestion of food
![Page 3: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/3.jpg)
![Page 4: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/4.jpg)
4
Hunger & Appetite• The amount of food
that a person ingests is determined principally by intrinsic desire for food is called hunger
• The type of food that a person preferentially seeks is determined by appetite
![Page 5: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/5.jpg)
Objectives
• Specific Objectives: At the end of the lesson student will be able to:
• List the Functions of tongue• Define Mastication and describe Importance of Chewing• Describe the components of Chewing Reflex• Name the Stages of Swallowing (Deglutition)• Describe the events occurring in Voluntary Stage of
swallowing • Outline the Series of Automatic Pharyngeal Muscle
Contractions occurring in Pharyngeal Stage of swallowing • Describe swallowing reflex
Goal/Aim: To give the understanding of the physiology of Mastication and Deglutition
![Page 6: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/6.jpg)
Lesson Contents• Functions of tongue• Mastication (Chewing)
– Control (Nerve Supply) of Muscles of Chewing– Chewing Reflex– Importance of Chewing
• Swallowing (Deglutition)– Voluntary Stage– Pharyngeal Stage (Involuntary)
• Series of Automatic Pharyngeal Muscle Contractions
– swallowing reflex
© Prof. Dr. Rashid Mahmood6
![Page 7: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/7.jpg)
Functions of tongue1. Speech2. Taste3. Chewing4. Swallowing5. Lingual lipase6. Cleansing of teeth7. Moistening of lips
![Page 8: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/8.jpg)
Ingestion of food
•Ingestion
•Mastication •Swallowing
![Page 9: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/9.jpg)
Mastication (Chewing)•Teeth
•Anterior (Incisors) •Posterior (Molars)
•Cutting •Grinding
![Page 10: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/10.jpg)
![Page 11: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/11.jpg)
Muscles of mastication
![Page 12: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/12.jpg)
Control (Nerve Supply) of Muscles of Chewing
• Motor Branch of 5th Cranial Nerve Specific reticular areas in brain Stem taste Centers
• Nucleus of Tractus Solitarius, and nucleus ambiguus
• Hypothalamus• Amygdala• Cerebral Cortex
![Page 13: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/13.jpg)
Chewing Reflex• Components of reflex
1. Stimulus2. Receptors3. Afferent Nerve4. CNS5. Efferent Nerve6. Effector7. Response
• Components of Chewing reflex
1. Bolus of Food2. Receptors of Sensory
Nerves3. 5th Nerve4. Swallowing Centre5. 5th Nerve6. Muscles of Mastication7. Reflex Inhibition
→Rebound Contraction (Stretch Reflex)
![Page 14: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/14.jpg)
Importance of Chewing
•Easy •passage •of food
•Prevent •excoriation
•of GIT
•↑Surface •area for
•Digestion
•Breaking•Of
•Indigestible•Membrane
•Chewing
![Page 15: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/15.jpg)
Assessment Q. No.1 • How does the Chewing Reflex cause
Contraction of Muscles of Mastication?
© Prof. Dr. Rashid Mahmood 15
![Page 16: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/16.jpg)
Ingestion of food
•Ingestion
Mastication •Swallowing
![Page 17: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/17.jpg)
Swallowing (Deglutition)
• Pharynx (Respiration → Swallowing)
• Three stages;–Voluntary Stage–Pharyngeal Stage (Involuntary)–Esophageal Stage (Involuntary)
![Page 18: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/18.jpg)
Voluntary Stage• Voluntarily Squeezed or
Rolled Posteriorly• Pressure of Tongue Upward
and backward• From here onward: Automatic
![Page 19: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/19.jpg)
Voluntary Stage
![Page 20: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/20.jpg)
Assessment Q. No.2 • What is direction of the tongue movement
during Voluntary Stage of Swallowing?
© Prof. Dr. Rashid Mahmood 20
![Page 21: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/21.jpg)
Swallowing (Deglutition)
• Three stages;Voluntary Stage–Pharyngeal Stage (Involuntary)–Esophageal Stage (Involuntary)
![Page 22: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/22.jpg)
22
Pharyngeal Stage (Involuntary)
![Page 23: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/23.jpg)
•23Swallowing
Oropharyngeal stage of swallowing
Resting
![Page 24: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/24.jpg)
Resting
![Page 25: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/25.jpg)
Swallowing
Oropharyngeal stage of swallowing
Resting
![Page 26: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/26.jpg)
![Page 27: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/27.jpg)
Assessment Q. No.3 • Name the structure that moves upward
during pharyngeal stage of swallowing.
© Prof. Dr. Rashid Mahmood 27
![Page 28: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/28.jpg)
Series of Automatic Pharyngeal Muscle Contractions
1. Soft Palate pulled upward↓
Posterior Nares Closed ↓
Prevents Reflux of food into Nasal Cavities
![Page 29: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/29.jpg)
Series of Automatic Pharyngeal Muscle
Contractions2. Palatopharyngeal
folds pulled Medially ↓
Selective Slit
![Page 30: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/30.jpg)
Series of Automatic Pharyngeal Muscle
Contractions3. Vocal Cords strongly approximated + Larynx
pulled upward & anteriorly + (Ligaments
prevent upward movement of Glottis)
↓ Epiglottis swings backward over opening of Larynx
↓ Prevent Passage of into Trachea
![Page 31: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/31.jpg)
Series of Automatic Pharyngeal Muscle Contractions
4) Upward movement of Larynx ↓ Opening
of esophagus enlarged + Relaxation of Upper Esophageal Sphincter
↓ Easy
movement of food
![Page 32: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/32.jpg)
Series of Automatic Pharyngeal Muscle
Contractions5. Muscular wall of Pharynx contracts
(Peristalsis)
Time taken by pharyngeal stage: < 6 seconds
![Page 33: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/33.jpg)
Pharyngeal Stage (Contd --------)
• Nervous Initiation (Reflex)–Most sensitive tactile area:
• Ring around pharyngeal opening; Greatest sensitivity on Tonsillar Pillars
–Effect on Respiration:• Swallowing centre inhibits Respiratory
centre of Medulla
![Page 34: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/34.jpg)
Pharyngeal Stageswallowing reflex (Contd --------)
1. Stimulus→ Touch2. Receptors→ Tactile3. Afferent Nerve→ 5,94. CNS→ Swallowing Centre (Medulla &
Lower Pons)5. Efferent Nerve→ 5,9,10,126. Effector→ Muscles of Pharynx & Upper
esophagus7. Response → Contraction
![Page 35: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/35.jpg)
Assessment Q. No.4 • What is swallowing reflex?
© Prof. Dr. Rashid Mahmood 35
![Page 36: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/36.jpg)
Summary • Ingestion of food involves two processes: Mastication
(Chewing) & Swallowing (Deglutition)• Teeth cut & grind the bolus of food• Mastication is brought about by Muscles of Chewing,
Controlled mainly by 5th Nerve.• Chewing Reflex, initiated by bolus of food in mouth results in
reflex inhibition of Muscles of Mastication. This results in Stretch Reflex, causing their Rebound Contraction
• Swallowing (Deglutition) occurs in three stages: Voluntary Stage, Pharyngeal Stage and Esophageal Stage
• Voluntary Stage involves mainly tongue, pushing the bolus of food in pharynx
• Pharyngeal Stage is Involuntary; in this stage swallowing reflex results in Series of Automatic Pharyngeal Muscle Contractions
![Page 37: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/37.jpg)
Learning resources• Guyton and Hall (Text book of physiology),
13th edition, P.708-709• Ganong (Text book of physiology), 24th
Edition, P. 500-501• Walter F. Boron Medical Physiology, 2nd
Edition, P.890-891
© Prof. Dr. Rashid Mahmood 37
![Page 38: Mastication and deglutition i](https://reader035.vdocuments.net/reader035/viewer/2022062316/58a26e321a28ab94628b5257/html5/thumbnails/38.jpg)
© Prof. Dr. Rashid Mahmood 38