speech mechanism chapter 8 Flashcards
part 1 or first half of chapter 8
Mastication
Chewing process - grinding and crushing food
Preparing food for swallowing
Deglutition
Swallowing the food - complex process of
moving bolus (ball of food/ liquid) from
pharynx into esophagus
Mastication and
Deglutition process may involve the following:
-Orbicularis oris
– Intrinsic/extrinsic tongue muscles
– Velar elevators
– Pharyngeal constrictors
Mastication and
Deglutition Invokes more than
55 pairs of muscles
along with cranial and spinal nerves
Feeding skills are both
preparatory
and supportive of the speech act
Iowa Oral Pressure Instrument (IOPI)
Flexible ball that measures force - tongue or lips
Electromyography
Measures muscle function during swallowing
Multislice computer aided tomography
3 dimensional representation of structures
Pharyngeal manometry
Pressure measure
Modified barium swallow study
(MBSS)
Videoradiographically record individual
ingesting barium of various textures -
anterior and lateral views
– Definitive test of oropharyngeal dysphagia
Nasoendoscopy
Direct visualization of pharyngeal space
Fiberendoscopic evaluation of
swallow (FEES)
Detect aspiration and pharyngeal residue,
can visualize structures - see tumors
– Do not have radiology exposure or
consumption of barium
Ultrasound
Observe movement during swallowing but
bone impedes visualization
development of swallowing begins
before birth as early as 10 weeks ga
nonnutritive sucking
15 weeks, suckling also stimulable
The newborn gains nutrition through
rooting reflex
rooting reflex
Infant responds to tactile stimulation of lips
or cheek
Infant turns toward stimulus and opens mouth
Suckling relfex allows
infant to receive food
from mother’s breast in first six months
suckling is triggered by
contact to inner margin of lips causing piston- like tongue protrusion and retraction
suckling is replaced
by sucking more complex process causing negative pressure to draw liquid in
what does the Velum of infant do?
“locks” into
space between epiglottis and
tongue this action seals off infants airway
what is bolus?
a ball of liquid that cannot enter the respiratory passageway
infants can…..
breathe while swallowing
how does the Infant’s Oral-Pharyngeal
Structures differ from adult structures
– Oral cavity is smaller
– Larynx elevated at birth
*Descends over the first four years
– Velum is relatively larger
– Hyoid elevated and relatively
forward
– No dentition in neonate
what are the stages of mastication and deglutition?
-oral preparatory stage
-oral transport stage
-pharyngeal stage
-esophageal stage
Oral preparatory stage
(mastication)
Oral transport stage
(propulsion of
bolus)
Pharyngeal stage
(pharyngeal swallow)
Esophageal stage
(esophageal transit)
centrally generated patterns are
mastication and tongue movements are largely reflexive
stages for Food prepared for swallowing
Food kept in mouth by sealing of lips
* Food ground up by lingual muscles
and muscles of mastication
* Food mixed with saliva to form a
bolus in preparation for swallowing
* Sensory receptors in the oral cavity
continually monitor the bolus
orbicularis oris
maintains oral seal
mentalis
elevates lower seal
buccinator
flattens cheeks
risouris
flattens cheeks
masseter
elevates mandible (V)
temporalis
elevates mandible; moves mandible grinds mandible laterally (V)
lateral pterygoid
protrudes and grind mandible (V)
facial muscles
orbicularis oris , mentalis, buccinator, and risouris (cn VII)
mandiblular muscles
masseter, temporalis, medial pterygoid, and lateral pterygoid (V)
tongue muscle (digastric)
elevates hyoid; depresses mandible (V,VII)
tongue muscle: geniohyoid
elevates hyoid; depresses mandible (XII)
mylohyoid : tongue muscle
elevates floor of mouth (V)
superior longitudinal : tongue muscle
elevates tip; deviates tip (XII)
tongue muscle; inferior longitudinal
depresses tip; deviates tip (XII)
genioglossus :tongue muscle
moves tongue body ; cups tongue (XII)
tongue muscle : styloglossus
elevates posterior tongue (XII)
tongue muscle: palatoglossus
elevates posterior tongue (IX, X, XI)
soft palate muscle : palatoglossus
depresses velum (IX, X, XI)
soft palate muscle: palatopharyngeus
depresses velum (X, XI)
When the bolus is ready to be
swallowed
Bolus pushed back toward the
oropharynx by the tongue in a
front to back squeezing action Voluntary or involuntary
Muscles involved in oral stage
Mandibular muscles
– Tongue muscles
vertical
cups and grooves tongue (XII)
Pharyngeal Stage is when
Complex sequence of reflexively
controlled events
the pharyngeal stage begins
Begins when bolus reaches
faucial pillars
Bolus propelled through
pharynx
to relaxed esophageal sphincter
which receives bolus
Central pattern generator circuits
Control mechanism for highly organized
and involuntary movements
A tight seal is formed
to
protect the airway
Food passes over epiglottis than
through the pyriform sinuses to
the esophagus
Hyolaryngeal elevation
elevation of the larynx is a key player in
relaxation of the upper esophageal sphincter
and protection of the airway
Pressurization of the pharynx
Driving force behind bolus propulsion into
the esophagus
Airway protection
vocal folds tightly adduct at the initial stage
of the swallow
Pharyngeal timing
contract about 300 ms (about 1/3 second)
after the liquid bolus is introduced orally
Upper esophageal sphincter relaxation
during the swallow the UES relaxes and
opens up as the larynx and hyoid move up
and forward.
levator veli palatini
elevates soft palate (X, XI)
Tensor veli palatini
Dilates Eustachian Tube (V)
Musculus uvulae
Shortens soft palate (X, XI)
palatopharyngeus
constricts oropharynx to channel bolus (X, XI)
salphingopharyngeus
elevates pharynx (XI)
stylopharyngeus
raises larynx (IX)
cricopharyngeus
relaxes esophageal orifice (X, XI)
middle constrictor
narrows pharynx (X, XI)
Inferior constrictor
narrow pharynx (X, XI)
Laryngeal cricoarytenoid, transverse aryteniod, and oblique arytenoid
adduct vocal (X)
laryngeal muscle: Aryepiglotticus
retracts epiglottis; constricts aditus (X)
laryngeal muscle: thyoepiglotticus
dilates airway following swallow (X)
what happens in the Final stage of mastication and
deglutition
-Purely reflexive and not within
voluntary control
– Swallowing involves peristaltic
movement of the bolus through the
esophagus
– During swallow, respiration ceases for
a second
– Bolus of food enters the stomach
