Oral
often divided into two phases:
- Oral Preparatory Phase
When food is manipulated in the mouth and prepared for the swallow - Oral Phase
When the tongue propels the food posteriorly until the pharyngeal swallow is triggered
Pharyngeal Stage
- past the faucial pillars
- when the pharyngeal swallow is triggered and the bolus is moved through the pharynx
esophageal stage
When esophageal peristalsis carries the bolus through the cervical and thoracic esophagus and into the stomach
sensory recognition component of oral prep
- food approaches mouth
- mouth begins to prepare
- mouth movements depend on type of material (viscosity) ex. solid, liquid, and amount
from the time material enters mouth..
labial seal is maintained
-required an open nasal airway and nasal breathing
how material is help within the oral cavity
liquid:
-between tongue and anterior hard palate
solid:
-between midline of tongue and hard palate with the tongue tip elevated and contacting the anterior alveolar ridge OR held on floor of mouth in front of tongue
tongue thrust
when the bolus is more anteriorly between the tongue and the anterior teeth
(reverse swallow pattern)
oral prep phase of deglutition for material
- requires mastication
- involves rotary lateral movements of the mandible and tongue
tongue positions material on teeth, when food is crushed it falls medially toward the tongue. tongue then moves the material back onto the teeth in order to complete mastication (chewing)
liquid volume range
1 (saliva)-17/20 (cup drinking) mL
solid volume range
5-7 cc (pudding consistency)
3-5 cc for hicker viscosity (mashed potatoes)
2 cc for meat
what happens if volume is too large (piecemeal swallow)
tongue will subdivide the food after chewing and only segmented boluses will be swallowed at a time
-holding excess food in your cheeks while you swallow part of what you can then swallow again
larynx and pharynx during oral prep
- at rest
- airway is open, nasal breathing continues
- VFs open
It is in this area however that if deficits occur within the oral stage that material may trickle into the pharynx and possibly the open airway
oral stages begins when
tongue starts to move the bolus posteriorly
oral stage tongue movement
- tongue tip moves upward in a smooth fashion
- midline sequentially squeezed bolus against hard palate
- side and tip remain tightly pressed against alveolar ridge
- buccal musculature is engaged in assisting with propelling of material
avg time to complete oral stage
1-1.5 seconds
longer than this is abnormal
pharyngeal stage begins when
food passes the faucial pillars
triggering the pharyngeal swallow
Sensory receptors in the oropharynx and tongue are stimulated as the tongue moves the bolus posteriorly
- Send messages to the cortex and brainstem
The oral stage of the swallow is terminated and the pharyngeal swallow is triggered (typically)
- When the bolus “bolus head” passes any point between the anterior faucial pillars and the point where the tongue base crosses the lower rim of the mandible
relationship between voluntary and reflex
“Both voluntary and reflex components are involved in the normal swallow. Neither mechanism alone is capable of producing swallowing with the regularity and immediacy which is necessary during the normal process of oral feeding” Rouche (1980)
The sensory portion of the pharyngeal swallow is carried out by Cranial nerves IX, X and XI
The motor portion of the pharyngeal swallow is carried out by Cranial nerves IX and X
VP closure
Variable from person to person
Involves elements of elevation and retraction of the soft palate, inward movement of the posterior and/or lateral pharyngeal walls and anteriorly bulging adenoid pad
Can functionally swallow with impairment if the tongue base makes contact with the post pharyngeal wall
elevation and anterior movement of hyoid and larynx
Hyoid bone and larynx move anteriorly by the pull of the floor of mouth muscles (anterior belly of digastric, mylohyoid, geniohyoid and laryngeal elevator – thyrohyoid)
-Pulls up and forwards
Elevation contributes to closure of the airway entrance and forward movement contributes to the opening of the UES
closure of larynx
Is a bottom up process beginning with the true vocal folds and progressing through the laryngeal vestibule
- Clears penetration
Larynx is elevated and pulled forward
- Elevation thickens the base of the epiglottis, assisting in the closure of the laryngeal vestibule
The airway is closed for ~1/3 to 2/3 second during a single swallow
During sequential cup drinking for more than 5 seconds
cricopharyngeal opening (series of actions)
- Tension in the cricopharyngeal muscular portion of the sphincter is released
- Laryngeal anterior superior motion is seen to open the sphincter (o.1) seconds later
- The sphincter is yanked open by the motion of the larynx resulting from the upward and forward pull of the floor of the mouth muscles
- The leading edge of the bolus reaches the sphincter and the pressure within the bolus widens the opening
- The bolus passes through the sphincter
- The larynx lowers
- The cricopharyngeus muscle returns to same level of contraction
tongue base and pharyngeal wall action
The tongue shape is ramp like and directs the bolus into the pharynx
The tongue base retraction and pharyngeal wall contraction occur when the bolus tail reaches the tongue base level.
When base of tongue and pharyngeal wall make contact, increased pressure occurs and the pharyngeal wall contractions continues down the pharynx to the UES
pharyngeal transit time
Time it takes for the bolus to move from the point at which the pharyngeal swallow is triggered through the cricopharyngeal juncture into the esophagus – (1 second or less)
epiglottis
Directs the material around the airway rather than over the airway
The two portions of the bolus join again at the level of the opening of the esophagus
esophageal phase begins
Begins where the bolus enters the esophagus at the UES until it passes into the stomach at the LES
esophageal transit time
Material is moved through peristalsis
Transit time can vary from 8 to 20 seconds
difference between UES and LES
UES – musculoskeletal valve made up of the cricopharyngeus muscle and the cricoid muscle
- Opens to allow food to enter the esophagus
LES – muscular sphincter that allows food to enter the stomach
- Designed to keep food and stomach acid in the stomach and prevents reflux of material coming back from stomach into the esophagus