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
Slide 3
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
Slide 4
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.
Slide 5
1. THEORY OF CONSTANT PROPORTION THEORY OF CONSTANT PROPORTION
2. THEORY OF ORAL EXPULSION 3. THEORY OF NEGATIVE PRESSURE 4.
THEORY OF INTEGRAL FUNCTION THEORY OF INTEGRAL FUNCTION
Slide 6
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
Slide 7
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
Slide 8
Phases of the mature deglutition cycle 1. Preparatory phase 2.
Oral phase 3. Pharyngeal phase 4. Oesophageal phase
Slide 9
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.
Slide 10
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.
Slide 11
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.
Slide 12
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.
Slide 13
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.
Slide 14
Slide 15
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
Slide 16
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.
Slide 17
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.
Slide 18
Slide 19
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'.
Slide 20
Slide 21
Figure 22.13d, e
Slide 22
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
Slide 23
Slide 24
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.
Slide 25
Slide 26
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
Slide 27
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
Slide 28
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
Slide 29
Slide 30
Slide 31
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
Slide 32
respiration phonation resonation articulation*
Slide 33
structures of pharynx, nasal and oral cavity way of modifying
airstream articulation = joining together of speech organs for
production of phonemes
Slide 34
supported by maxilla (upper jaw) and lower jaw (mandible) Body
function - receive and contain food Speech function - varied
movement: rounded, tensed: obstruct air flow
Slide 35
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
Slide 36
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
Slide 37
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
Slide 38
tongue -major articulator/ muscle and mobile body function -
direct food to back of oral cavity speech function - direction of
air flow: contacts
Slide 39
: approximates other structures; changes size of oral cavity
mandible body function - chewing speech function - change size of
oral cavity
Slide 40
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
Slide 41
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
