Deglutition (Swallowing)

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Deglutition(Swallowing)

• Sitthichai Wanachantararak

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1/3 Teaspoon Honey Consistency
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Deglutition (Swallowing)
Figure 22.13a-c
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Deglutition (Swallowing)

• Involves the coordinated activity of the tongue,
  soft palate, pharynx, esophagus and 22 separate
  muscle groups
• Buccal phase bolus is forced into the
  oropharynx
• Pharyngeal-esophageal phase controlled by the
  medulla and lower pons
• All routes except the one into the digestive
  tract are sealed off
• Peristalsis moves food through the pharynx to the
  esophagus

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infantile (or immature) swallow

• has the following characteristics
• 1. The jaws are apart, with the tongue between
  the gum pads
• 2. The mandible is stabilized mainly by
  contraction of the muscles innervated by the VII
  (seventh) cranial nerve and the interposed
  tongue
• 3. The swallow is guided and to a great extent
  controlled by sensory interchange between the
  lips and the tongue

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mature swallow

• Usually, by 18 months of age, the following
  mature swallow characteristics are to be
  observed
• 1. The teeth are together
• 2. The mandible is stabilized by contraction of
  the mandibular elevators, these being primarily
  innervated by the trigeminal nerve
• 3. The tongue tip is held against the palate
  above and behind the incisors
• 4. There are minimal contractions of the lips
  during the mature swallow.

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Theories of deglutition

1. THEORY OF CONSTANT PROPORTION
2. THEORY OF ORAL EXPULSION
3. THEORY OF NEGATIVE PRESSURE
4. THEORY OF INTEGRAL FUNCTION

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THEORY OF CONSTANT PROPORTION

• 1. Oral phase the bolus is formed and
  transported under voluntary control to the
  pharynx
• 2. Pharyngeal phase following receipt of the
  bolus, the pharynx is activated to propel the
  food to the oesophagus
• 3. Oesophageal phase passage of bolus down the
  oesophagus to the stomach by oesophageal
  contraction

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THEORY OF INTEGRAL FUNCTION

• based on cinefluorographic, myometric and
  electromyographic studies, and considers that the
  act of deglutition is a total dynamic process.
  This is the currently accepted theory

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THEORY OF INTEGRAL FUNCTION

• Phases of the mature deglutition cycle
• 1. Preparatory phase
• 2. Oral phase
• 3. Pharyngeal phase
• 4. Oesophageal phase

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1/3 Teaspoon Ground Meat and 1/4 Cookie
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1. Preparatory phase

• starts as soon as liquids are taken into the oral
  cavity or after the bolus has been masticated.
• The liquid or bolus is position on the dorsum of
  the tongue, with the oral cavity sealed by the
  lip and the tongue.
• The positioning of a liquid on the dorsum of the
  tongue before transporting it to the final
  swallow-preparatory position may be facilitated
  through suction created by moving the tongue
  posteriorly after a peripheral seal has been
  established within the cavity.

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1. Preparatory phase

• A final characteristic is the stabilization of
  the oral cavity
• 'Considerable pressure' is exerted between the
  teeth in the molar region as the lip is elevated
  to position the bolus in adult subjects, although
  it is apparent that in the predentition or mixed
  dentition phases, other mechanisms would need to
  be used for this purpose.

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2. Oral phase

• introduced by the withdrawal of the soft palate
  from its rest position against the root of the
  tongue, where it is held by the tensor palati
  muscles.
• In this phase the soft palate moves upward and
  the tongue drops downward and backward.
• At the same time, the larynx and hyoid move
  upward.
• The elevation of the hyoid may actually be
  initiated as the bolus is positioned in the
  swallow-preparatory phase.

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2. Oral phase

• These combined movements make a smooth path for
  the bolus as it is pushed from the oral cavity by
  the peristaltic-Iike action of the tongue.
• Solid food is actually pushed by the tongue,
  whereas fluids flow ahead of the lingual
  contractions.
• During this phase, the oral cavity maintains an
  anterior and lateral seal, and is stabilized by
  the muscles of mastication.

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2. Oral phase

• When a large bolus is to be swallowed, most or
  all of it is moved into the preparatory position
  and is then neatly sectioned by the tongue in
  consecutive swallows until the oral cavity is
  empty.

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3. Pharyngeal phase

• This phase begins as the bolus passes from the
  tongue through the fauces.
• The pharyngeal tube is raised and the nasopharynx
  sealed by closure of the soft palate against the
  posterior pharyngeal wall.
• Active participation of the pharynx is elicited
  by soft palate and bolus contact with the
  pharyngeal wall, an action which consists of an
  elevation of the entire

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3. Pharyngeal phase

• pharyngeal tube and a sphincteric reduction in
  the lumen between the upper pharyngeal wall and
  soft palate.
• The hyoid and the base of the tongue move forward
  as both the tongue and the pharynx continue their
  peristaltic-like action on the food bolus.
• Passage of such a bolus through the pharynx
  during the mature swallowing is enhanced by an
  anterior movement of the hyoid and root of the
  tongue.

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3. Pharyngeal phase

• Finally, there is an abrupt elevation of the
  larynx as the bolus reaches the laryngo-pharynx
  and, this is then followed by elevation of the
  floor of the laryngophary and opening of the
  oesophageal sphincter.

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4. Oesophageal phase

• This phase commences as soon as food passes the
  cricopharyngeal sphincter. While peristaltic
  movement carries the food through the oesophagus,
  the hyoid bone, soft palate and tongue return to
  their 'original positions'.

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Deglutition (Swallowing)
Figure 22.13d, e
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Esophagus

• Peristalsis
• Produced by a series of localized reflexes in
  response to distention of wall by bolus.
• Wave-like muscular contractions
• Circular smooth muscle contract behind, relaxes
  in front of the bolus.
• Followed by longitudinal contraction (shortening)
  of smooth muscle.
• Rate of 2-4 cm/sec.
• After food passes into stomach, LES constricts.

Insert 18.4a
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Stomach

• Most distensible part of GI tract.
• Empties into the duodenum.
• Functions of the stomach
• Stores food.
• Initiates digestion of proteins.
• Kills bacteria.
• Moves food (chyme) into intestine.

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Conclusion for swallowing
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Oral Preparatory Phase

• tongue positions material on the teeth
• rotary lateral movement of the mandible and
  tongue during mastication
• tongue moves the material back onto the teeth as
  the mandible opens
• after cycle is repeated numerous times, a bolus
  is formed
• during active chewing, the soft palate is not
  pulled down and forward and premature spillage is
  common and entirely normal

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Oral Preparatory Phase
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Pharyngeal Phase

• elevation and retraction of the velum and
  complete closure of the velopharyngeal to prevent
  passage into the nasopharynx
• elevation and anterior movement of the hyoid and
  larynx
• closure of the larynx at the true vocal folds,
  the laryngeal entrance and the epiglottis to
  prevent material from entering the airway

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Pharyngeal Phase
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Second swallow

• A second swallow was needed to clear all the
  material
• 1/3 Teaspoon Ground Meat and 1/4 Cookie In this
  segment, please note
• The rotary lateral movement of the mandible and
  tongue
• The formation of the bolus
• During chewing, the soft palate is not pulled
  down and forward and material falls into the
  pharynx partially before the pharyngeal phase is
  triggered
• Bolus size decrease with the viscosity of food
  J.P. swallowed twice on the ground meat material

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Second swallow
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Control of deglutition
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Control of deglutition
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Speech

• 1 Speech Mechanism
• Physiological phonetics
• All sounds which come from the mouth and nose
  arethe result of interruptions and/or
  modifications of a stream of air moving from the
  lungs through
• trachea - larynx
• pharynx - oral cavity
• nasal cavity

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4 speech process

• respiration
• phonation
• resonation
• articulation

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Articulation

• structures of pharynx, nasal and oral cavity
• way of modifying airstream
• articulation joining together of speech organs
  for production of phonemes

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lips

• supported by maxilla (upper jaw) and lower jaw
  (mandible)
• Body function - receive and contain food
• Speech function - varied movement rounded,
  tensed obstruct air flow

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• teeth
• body function - cut and grind food
• speech function - anatomical obstacle for lips
  or
• tongue
• alveolar ridge (gum ridge of maxilla
• body function - none houses teeth
• speech function - point of contact/constriction

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• hard palate - bony structure posterior to
  alveolar ridge
• body function - contain food in oral cavity
• speech function - point of contact defines
  shape of oral cavity

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• soft palate/velum - muscular structure posterior
  to hp
• body function - separate oral cavity and nasal
• cavity
• speech function - direction of air flow
  -open/close vp port point of contact

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• tongue -major articulator/ muscle and mobile
• body function - direct food to back of oral
  cavity
• speech function - direction of air flow
  contacts

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other structures

• approximates other structures
• changes size of oral cavity mandible
• body function - chewing
• speech function - change size of oral cavity

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• Oral cavity
• from mouth opening to posterior wall of pharynx
  (posterior pharyngeal wall)
• body function breathing, eating
• speech channels airstream contributes oral
  resonance
• Nasal cavity - extends from nostrils (nares) to
  posterior

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• Pharynx
• posterior portion of nasal cavity down through
  back of oral cavity to larynx
• body function breathing
• speech contributes nasal resonance
• Vocal cords/folds
• in lateral walls of larynx
• body function respiratory protection
• phonation

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Thank you for your attention