Download Dysphagia: Structure and process of the normal swallow

Dysphagia: Terminology, structure,
and process of the normal swallow
Scott S. Rubin, Ph.D.
Associate Professor, LSUHSC-NO
SPTHAUD 6218
The Swallow: Structure and processes
• Presentation topics include:
▫ SLP involvement
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What is Dysphagia (definitions)
Structures associated with swallow
Neurological control of swallow
Stages of normal swallow
ASHA Preferred Practice
• Link to ASHA Preferred Practice Patterns for
the Profession of Speech-Language Pathology
• http://www.asha.org/docs/html/PP2004-00191.html
• Please familiarize yourself with it!!!
The Swallow: Structure and processes
• What is Dysphagia?
 Those with dysphagia may experience pain while
swallowing. Some people may be completely unable to
swallow or may have trouble swallowing liquids, various
consistencies of foods, and/or saliva.
 Eating becomes a challenge and filled with fear or
anticipation of problems.
The Swallow: Structure and processes
▫ Dysphagia (continued)
 Dysphagia may cause difficult in taking in enough
calories (food and fluids) to nourish the body.
 Lasting dysphagia can lead to serious health problems
and death.
 Also, if managed poorly by SLP – can contribute to poor
outcome!
The Swallow: Structure and processes
• Common classifications of dysphagia
• Oral phase–sucking, chewing, and moving food or liquid
into the throat (usually subdivided to Oral Preparatory
and Oral Transit)
• Pharyngeal phase–starting the swallowing reflex,
squeezing food down the throat, and closing off the
airway to prevent food or liquid from entering the airway
(aspiration) or to prevent choking
• Esophageal phase–relaxing and tightening the openings
at the top and bottom of the feeding tube in the throat
(esophagus) and squeezing food through the esophagus
into the stomach
• Topic for later presentation
The Swallow: Structure and processes
• Associated Terminology
▫ Penetration – Material moves into vestibule above
the true vocal folds
▫ Aspiration –Material breaches vocal folds into lungs.
▫ Silent Aspiration – occurs but no signs/symptoms
The risk for aspiration is not limited to meal times.
It can occur ANY TIME, day or night.
Includes food, drink, medication, saliva, and vomit
• Potential Consequences of Aspiration
▫ Pneumonia (i.e., Aspiration Pneumonia)
▫ Perminant Lung Damage
▫ Death !
The Swallow: Structure and processes
▫ Dysphagia Triggers - Symptoms or signs that
may signal the occurrence of aspiration
 Coughing – forceful exhalation of air
 Choking – airway is blocked
 GERD/Reflux – stomach contents come back up into
esophagus or mouth
 Much more terminology presented in context.
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
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CN V
CN VII
CN IX
CN X
CN XII
Trigeminal
Facial
Glossopharyngeal
Vagus
Hypoglossal
▫ Each Nerve on following slides…
 And … other nerves? Impact? – explore on own and have examples (could
be on exam or comps)!
 Vision
 Smell
 Eye movement…
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
▫ CN V -- Trigeminal
 sensory and motor- innervates the face
 important in chewing
 located at the level of the pons
The Swallow: Structure and processes
• CN V – Trigeminal
3 Branches
Opthalmic V1(sens)
Maxillary V2 (sens)
Mandibluar V3 (mixed)
Sensory from forehead and eye – (over
V1), cheek (over V2) and
lower face and jaw (V3).
Motor for muscles of mastication,
soft palate, mylohyoid , chin:
Mandibular
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
▫ CN VII -- Facial
 sensory and motor fibers
 important for sensation of oropharynx & taste to
anterior 2/3 of tongue
The Swallow: Structure and processes
• CN VII -- Facial
• Facial nerve proper:
The largest component of the
facial nerve.
Voluntary control of the muscles
of facial expression, as well as
the posterior belly of the digastric,
stylohyoid and stapedius muscles.
• CN VII -- Facial
• Nervous Intermedious
carries rest of sensory fibers and autonomic
information.
▫ Yellow = F. nerve Proper.
▫ Orange, Blue, Green =
Nerv. Intermedious
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
▫ CN IX -- Glossopharyngeal
 contains both sensory and motor fibers
 important for taste from posterior tongue, sensory
and motor functions of the pharynx
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
▫ CN IX – Glossopharyngeal
• It receives sensory fibers from:
posterior one-third of the
tongue, tonsils, Pharynx,
middle ear, and the
carotid body.
• Autonomic fibers to the
parotid gland
• It also supplies motor
fibers to stylopharyngeus
muscle and the upper
pharyngeal muscles.
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
▫ CN X -- Vagus
 contains both sensory and motor fibers
 important for taste to oropharynx, and sensation
and motor function to larynx and laryngopharynx.
 important for airway protection
The Swallow: Structure and processes
• CN X - Vagus - 3 branches
• Pharyngeal Nerve branch
▫ Motor and sensory fibers
▫ Motor to soft palate and pharynx
▫ Sensory to lower pharynx
• Superior Laryngeal N.
Branch – has 2 branches
• Internal laryngeal nerve
▫ Sensory from epiglottis and interior larynx
• External laryngeal Nerve
▫ Motor to cricothyroid muscle
and inferior constrictor muscle
• Recurrent Laryngeal N.B.
The Swallow: Structure and processes
• CN X - Vagus - 3 branches
• Recurrent Laryngeal Branch
Courses past larynx – neck
and upper chest – then
from chest up to larynx
▫ innervates all muscles of
the larynx
(except Cricothyroid)
The Swallow: Structure and processes
• Cranial Nerves Important in Swallowing
▫ CN XII -- Hypoglossal
 contains motor fibers that primarily innervate the
tongue
The Swallow: Structure and processes
▫ CN XII -- Hypoglossal
To all Intrinsic Muscles
of Tongue
And all but one
Extrinsic
The Swallow: Structure and processes
• Anatomy of Swallow
• Skeleton
▫ Hyoid Bone - attachment to epiglottis and strap
muscles.
▫ Thyroid Cartilage - anterior attachment of vocal folds.
Posterior articulation with cricoid cartilage.
The Swallow: Structure and processes
• Anatomy of Swallow
• Skeleton
▫ Cricoid Cartilage - complete ring. Articulates with
thyroid and arytenoid cartilages.
▫ Arytenoids - two cartilages which glide along the
posterior cricoid and attach to posterior ends of vocal
folds.
The Swallow: Structure and processes
Divisions of Structure
• Supraglottis - usually covered with respiratory epithelium
containing mucous glands.
▫ Epiglottis - leaf-shaped mucosal-covered cartilage, which projects over
larynx.
▫ Aryepiglottic folds - extend from the lateral epiglottis to the arytenoids.
▫ False vocal cords - mucosal folds superior to the true glottis.
Separated from true vocal folds by
the ventricle.
▫ Ventricle - mucosal-lined sac,
variable in size which separates the
supraglottis from the glottis.
The Swallow: Structure and processes
Divisions of Structure
• Glottis –
• true vocal folds attach to the thyroid cartilage
at the anterior commissure.
• The posterior commissure is mobile, as
the vocal folds attach to the arytenoids.
• Motion of the arytenoids effects
abduction or adduction of the larynx.
• The bulk of the vocal fold is made up
of muscle covered by mucosa.
• The vocal folds abduct for inspiration
and adduct for phonation& cough
The Swallow: Structure and processes
Divisions of Structure
▫ Subglottis - below the vocal folds
The Swallow: Structure and processes
Pyriform Sinus
The Swallow: Structure and processes
Valleculae
The Swallow: Structure and processes
Vallecula
Note aspiration in trachea.
The Swallow: Structure and processes
Review of Structures
Vallecula
Epiglottis
Upper Esophageal
Sphincter (UES)
Lower Esophageal
Sphincter (LES)
The Swallow: Structure and processes
• Glands
▫ Parotid Gland
▫ Located on side of face,
anterior to mastoid tip and
superior to the lower
▫ Facial nerve passes through
this gland.
The Swallow: Structure and processes
• Submandibular Gland
▫ Beneath floor of the mouth
The Swallow: Structure and processes
• Sublingual Glands - located below the
mucous membrane of the floor of the mouth,
adjacent to mandible and mylohyoid muscle.
The Swallow: Structure and processes
• Minor Salivary Glands - small collections of salivary
gland tissues are scattered throughout the oral mucosa,
and can also be seen in the pharynx, supraglottis, nose
and sinuses.
The Swallow: Structure and processes
▫ Oral Phase
 Oral Preparatory
 Goal: reduce food to a bolus and
position it for transport
 Initial transport (the bolus lacement) tongue positions the food to ready it for
reduction
 Reduction phase - bolus is chewed &
mixed with saliva
 Bolus placement - bolus is positioned
for transport
 Oral Transport
 The prepared bolus is transported from
anterior to posterior oral cavity for
passage to the pharynx.
The Swallow: Structure and processes
 Pharyngeal Phase
 Complete closure of velopharyngeal opening.
 Hyoid & Larynx begin their superior ascent
 Epiglottis begins to fold down – back.
▫ (to clarify - the epiglottis tilting or folding back and
down is as the result of surrounding structures’
movement – i.e., larynx elevating, contracting mouth
floor, & hyoid moving up and back) .
 Tongue base to posterior pharyngeal wall contact
 Top to bottom contractions of pharyngeal constrictor
muscles
 Continued superior movement of hyoid & larynx
 Laryngeal closure starts from bottom up
 Continued down-folding of epiglottis to inverted
position
 Anterior movement of hyoid
 Relaxation of cricopharygeus muscle & opening of
upper esophageal sphincter region
The Swallow: Structure and processes
 Esophageal Phase
 Peristalsis carries the bolus through
esophagus to the stomach.
 The lower espohageal sphincter opens.