Transcript swallowing 47

Deglutition
(Swallowing)
Sitthichai Wanachantararak
1/3 Teaspoon Honey Consistency
Deglutition (Swallowing)
Figure 22.13a-c
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
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
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.
Theories of deglutition
1.
THEORY OF CONSTANT PROPORTION
2.
THEORY OF ORAL EXPULSION
3.
THEORY OF NEGATIVE PRESSURE
4.
THEORY OF INTEGRAL FUNCTION
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
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
THEORY OF INTEGRAL FUNCTION
Phases of the mature deglutition cycle
1. Preparatory phase
2. Oral phase
3. Pharyngeal phase
4. Oesophageal phase
1/3 Teaspoon Ground Meat and 1/4 Cookie
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.
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.
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.
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.
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.
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
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 peristalticlike 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.
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.
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'.
Deglutition (Swallowing)
Figure 22.13d, e
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
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.
Conclusion for swallowing
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
Oral Preparatory Phase
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
Pharyngeal Phase
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
Second swallow
Control of deglutition
Control of deglutition
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
4 speech process
– respiration
– phonation
– resonation
– articulation*
Articulation
• structures of pharynx, nasal and oral cavity
• way of modifying airstream
• articulation = joining together of speech organs for
production of phonemes
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
• 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
• 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
• 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
• tongue -major articulator/ muscle and mobile
– body function - direct food to back of oral cavity
– speech function - direction of air flow: contacts
other structures
: approximates other structures;
• changes size of oral cavity mandible
– body function - chewing
– speech function - change size of oral cavity
• 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
• 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
Thank you for your attention