Week 1 Flashcards
The Anatomy and Stages of Swallowing
What is Dysphagia? and that does Dysphagia involve
Dysphagia is disorder or difficulty with swallowing. • Dysphagia involves disruption of any one or more of the stages of swallowing: Oral, Pharyngeal
and Oesophageal
what is dysphagia not?
It is not a disease or primary medical diagnosis itself, rather a symptom of an underlying disease process.
What does swallowing involve?
Swallowing is an extremely complex process that involves input and coordination from at least 26 pairs of muscles & 6 cranial nerves.
what are the 5 stages of the swallow?
- Oral Anticipatory
- Oral Preparation
- Oral Transit
- Pharyngeal stage
- Oesophageal stage
what swallowing stages are under voluntary control ?
The oral stage (Anticipatory+ Preparation + Transit) is under voluntary control i.e. it can be interrupted at any time
what swallowing stages are NOT under voluntary control ?
The pharyngeal & oesophageal stages are involuntary.
What is the primary role of the Anticipatory (Pre- Oral) Stage?
Pre-oral motor, cognitive, psychosocial, & somatoesthetic elements.
what happens in the Anticipatory (Pre- Oral) Stage?
Sensory acknowledgement that food is present leads to an appropriate or expected response (e.g. mouth opening, judging how much to put in your mouth, using smell, judging temperature).
What is the primary role of the Oral Preparatory Stage?
Preparation of food and fluid for oral transit & initiation of the pharyngeal swallow.
how long is the duration of the Oral Preparatory Stage?
As the oral preparatory stage is under voluntary control, its duration varies according to a range of factors (e.g. sensory, cognitive, emotive).
what are the first 6 steps of the Oral Preparatory Stage?
- The mouth & lips open to accept the bolus.
- The tongue forms a ‘groove’ to accept the bolus.
- The lips seal around the bolus to prevent anterior spillage of the bolus (1st of 4 valves; part of the pressure system).
- Tension in the lips & cheeks keeps the food in the correct Place.
- Food & liquid in the mouth stimulates taste, temperature, & pressure (touch) receptors.
- Saliva is produced by as the salivary glands are
activated.
What happens to Solids in the Oral Preparatory Stage?
Coordinated action of the tongue & jaw moves the bolus onto the teeth for mastication (rotatory chewing to grind & crush the bolus by the teeth).
what are the two oral control actions with solids in the Oral Preparatory Stage?
- Buccinator press: cheek tension flattens the cheeks & keeps the bolus within the “dental vault”.
- Contact of tongue & hard palate stops food tipping into pharynx- glossopalatal seal
What happens to solids during mastication in the Oral Preparatory Stage
The bolus is mixed with saliva this helps to form a moist cohesive bolus of appropriate size & consistency for swallowing. The tongue manipulates, shapes, holds & transfers the bolus into the oropharynx. Some of the bolus is allowed to collect in the valleculae.
what happens to liquids in the Oral Preparatory Stage
Lip seal & cheek tone help control & manipulate the liquid bolus & prevent anterior spillage from front (or corners) of the mouth
what is the Glossopalatal seal and why is it important in the Oral Preparatory Stage
tongue & soft palate contact seals the back of the oral cavity, containing the bolus within the mouth and prevents premature spillage into the pharynx (glossopalatal seal) before the swallow is triggered. more important for liquids than solids.
what is the key (8) anatomy of the Oral Preparatory Stage?
- Lips
- Cheeks
- Tongue
- Hard / soft palate
- Jaw
- Teeth
- Salivary glands
- Taste bud
What is the primary role of the Oral Transit Stage
Posterior propulsion of the bolus from the oral cavity into the pharynx following bolus preparation.
what are the first 5 steps of the Oral Transit Stage?
- Tongue tip elevates & presses against the hard palate occluding the oral cavity.
2. Tongue dorsum & cheek tension contain the bolus laterally.
3. Posterior tongue drops to open the back of the oral cavity.
4. Tongue-palate contact expands rom front to back – squeezing the bolus back along the palate & into the oropharynx, through the faucial arches.
5. The pharyngeal stage or reflexive swallow is triggered.
what is the (3) key anatomy of the Oral Transit Stage?
- Tongue
- Hard/soft palate
- Lips/cheeks
What are the primary roles of the Pharyngeal Stage?
1) Food passage: Propels the bolus through the pharynx, through the UES, to the oesophagus.
2) Airway protection: Ensures food / drink does not enter the larynx, trachea or lungs (i.e. preventing penetration & aspiration).
What is the Reflexive Swallow triggered by?
The pharyngeal stage is involuntary, representing an irreversible motor event.
- Timing / location of onset is variable.
- Triggered by sensory stimulation of: Superficial mucosal receptors in the soft palate / pharynx.
- Deep muscle receptors in the base of the tongue.
what is the function and role of the velopharyngeal seal?
the velopharyngeal seal prevents nasal regurgitation.
- Sphincter like action involving the velum, lateral and posterior pharyngeal wall.
- This seal also contributes to the pressure system.
when does the Pharyngeal Stage commence
as the bolus arrives in the valleculae
in the Pharyngeal Stage what happens after the bolus arrives in the valleculae?
The bolus is propelled through the lateral channels (pyriform sinuses) of the pharynx into the oesophagus.
when is the velopharyngeal seal active?
As the bolus is transferred back into the pharynx & the pharyngeal stage is triggered and the the velopharyngeal seal prevents nasal
how does the velopharyngeal seal function?
- Sphincter like action involving the velum, lateral and posterior pharyngeal wall.
- This seal also contributes to the pressure system.
what happens after the velopharyngeal seal is activated?
• The base of tongue retracts and the posterior pharyngeal wall moves forwards (BOT to PPW approximation)
what happens during BOT to PPW approximation?
This applies positive pressure on the bolus, moving it rapidly through the pharynx into the oesophagus.
what happens after BOT to PPW approximation?
The larynx is drawn upwards & forwards (hyolaryngeal excursion)
what happens during hyolaryngeal excursion?
helping to create negative pressure in the hypopharynx (below the bolus). Hyolaryngeal excursion also assists airway protection & stretches open the UES.
what happens after hyolaryngeal excursion?
As the bolus enters the pharynx the pharyngeal constrictor muscles sequentially shorten & narrow the pharynx (pharyngeal constriction
what happens during pharyngeal constriction?
peristaltic-like movement, squeezing the bolus through the pharynx towards the oesophagus.
what (3) happens after pharyngeal constriction?
i. Prior to the bolus arriving the cricopharyngeus muscle is released (relaxing the UES – this creates negative pressure below the bolus).
ii. Hyolaryngeal excursion then applies traction force to the UES – helping to achieve maximal UES opening.
iii. Pressure of the bolus further distends the UES.
what happens after the tail of the bolus passes through the UES?
UES closes tightly shut, preventing reflux.
what happens after the UES closes?
The hyoid bone then returns to its resting position & the airway reopens.
Brief pharyngeal stages of food passage!
- bolus arrives in the valleculae
- bolus is propelled through the lateral channels (pyriform sinuses) of the pharynx into the oesophagus.
- bolus is transferred back into the pharynx the velopharyngeal seal prevents nasal regurgitation
- BOT to PPW approximation
- hyolaryngeal excursion
- pharyngeal constriction
- The bolus is then drawn through the UES into the oesophagus.
- tail of the bolus passes through the UES which shuts.
- The hyoid bone then returns to its resting position & the airway reopens
what happens during Airway Protection in the pharyngeal stage?
- Epiglottic deflection
* Glottal closure
what is Epiglottic deflection?
The epiglottis tilts backwards to deflect the bolus away from the laryngeal vestibule or inlet. Hyolaryngeal excursion (most important) – upward & forward movement of the hyoid & larynx pulls the base from under the epiglottis (Biomechanical folding / spring), causing it to tilt backwards. Superior pressure from BOT (minor role).
what is Glottal closure ?
(laryngeal constriction- sphincter like action)
- Valving of the laryngeal vestibule involves:
> Closure or adduction of the true vocal cords
> Closure of the false vocal folds over the true vocal folds
what is the (5) Key Anatomy of the Pharyngeal stage?
- Pharynx
- Pharyngeal constrictor muscles
- Base of tongue
- Epiglottis
- Vocal folds / laryngeal muscles
what is the Primary Role of the Oesophageal Stage?
To move the bolus from the UES to the stomach for digestion
what happens during the Oesophageal Stage?
Relative ‘simple’ phase – peristaltic wave of contraction. Begins as the bolus passes through the UES. Oesophageal peristalsis occurs every 2 to 4 seconds - moves bolus in waves along the length of the oesophagus to the lower oesophageal sphincter (LES). Takes 6-20 seconds.
what is the Key Anatomy of the Oesophageal Stage?
- UES
- Oesophageus
- Oesophageal muscle
- LES
Describe the Neurophysiology of Swallowing
Swallowing is a complex sensorimotor behavior. Different levels of central nervous system from cerebral cortex to the medulla oblongata are involved. Pathways excite or inhibit the striated muscles of swallowing, innervated by the cranial nerves
How conscious is swallowing?
One of the most elaborate motor functions in humans that involves an integrated, complex motor sequence.The sensory & motor patterns of mastication & swallowing are typically performed with little effort or conscious awareness in healthy adults.
describe the Peripheral and Brain Stem Controls of swallowing.
‘sensory stimulation’ at the fauces, base of tongue, posterior pharyngeal wall and valleculae initiates Pharyngeal (or reflexive) swallow. this sensory info then This sensory info converges in medulla, specifically the Nucleus Tractus Solitarius (NTS): this is the ‘sensory swallowing centre’ in brainstem that integrates sensory info about bolus and programs the required swallow NTS then triggers the Ventral Swallowing Group (VSG): think of as ‘motor swallowing centre’ that then enables execution of programmed swallow
what is the motor and sensory role of the cortices in stuttering
Motor: Intent, Initiation, Programming, Execution
sensory:
