oral functions 4 - aerodigestive tract reflexes and speech Flashcards
what are the 3 stages in swallowing
- buccal phase = voluntary
- pharyngeal phase = involuntary
- oesophageal = involuntary
what is swallowing
- process by which the accumulated food bolus is transported through the lower pharynx and oesophagus to the stomach (feeding function)
- prevents ingested material from entering the lower airway (protective function)
how is bolus formed
- the water in saliva allows the bolus to stick together to be swallowed
why is swallowing potentially dangerous
- because the ‘food-way’ crosses the airway
how are liquids swallowed
- liquids are gathered on the tongue, anterior to the pillars of the fauces
- the mouth is separated from the pharynx by a posterior oral seal = this doesn’t happen with solid bolus
- the liquid bolus is then propelled through the oropharynx and hypo pharynx and then into the oesophagus
how is solid bolus swallowed
- chewed food material accumulates on the pharyngeal part of the tongue and vallecula (oropharynx)
- there is no true posterior oral seal
- the bolus is then propelled from the tongue through the hypo pharynx and then into the oesophagus
what are some key points of swallowing
- liquids are swallowed from the mouth = oral seal
- solids are swallowed from the oropharynx = no oral seal
- both are mixed rapidly through the hypo pharynx past the laryngeal inlet
what do tongue movements do in swallowing
- the forward movement of the tongue during the occlusal and initial opening phases creates a contact between the tongue and hard palate
- the contact zone moves progressively backwards, squeezing the processed food through the fauces
- tongue breaks up the bolus to be swallowed in smaller amounts
what are the swallowing events
- propulsion of food
- prevention of reflux
- protecting the airway
what is the duration of the masticatory sequence
- the duration varies with the different extents of food consistency
how strong are swallowing forces
- these are strong enough to move bolus up hill or down hill
how is reflux prevented
- elevation of the soft palate
- tongue (sides) contacts pillars of fauces
- tongue (dorsal) contacts posterior pharyngeal wall
- upper oesophageal sphincter stops reflux from oesophagus into pharynx
- lower oesophageal sphincter stops reflux from stomach into oesophagus
how can erosion occur
- stomach acid can erode teeth by reflux, vomitting, regurgitation and rumination
- when palatal surface erosion is present, 2/3 of the time stomach acid is responsible = causes cupping on the palatal surface - is intrinsic erosion
how can you prevent fizzy drinks causing erosion
- patients will not stop drinking these even if asked
- instead need to suggest that they drink them with a straw or only at mealtimes to lessen damage
what are other types of tooth surface loss than erosion
- attrition
- abrasion
- abfractions
what is attrition
- is tooth wear occlusally caused by contact between occluding teeth
- the teeth inter-digitate indication that attrition is occurring
- there are equal amounts between upper and lower
what is abrasion
- occurring on its own is unusual = might be caused by biting or chewing objects between the teeth
- the most common presentation of tooth wear it the result of a combined lesion involving erosion and abrasion
- acids weaken the outer 3-5 microns of mineralised tissue and increase the susceptibility of the enamel and dentine to abrasion from tooth brushing with or without toothpaste
what is abfraction
- stress lesion s
- wedge-shaped notch caused by the flexure and ultimate material fatigue of susceptible teeth at locations away from the point of loading
- the breakdown is dependant on the magnitude, duration, frequency and location of occlusal forces
- premolars are specifically at risk due to high occlusal load here
how is the airway protected during swallowing
- upward and forward movement of larynx
- closure of laryngeal inlet = aryepiglottic muscles, epiglottis
- adduction of vocal folds = movement of them towards midline of body, or towards other part
- stop breathing = apnoea
what is dysphasia
- sometime called aphasia
- a specific language disorder
- involving damage to particular parts of the brain = Broca’s area and Wernick’s area
what is dysphagia
- difficulty/inability to swallow
what is odynophobia
- pain on swallowing
- a pathological condition in which the affected person experiences extreme pain when swallowing be it foods, liquids, drugs
what is dysarthria
- difficulty speaking that is caused by problems with the muscle used in speech
- due to neuro-muscular defects = important to notice these in a patient as can affect treatment - e.g. dentures
what are some oral causes of language and speech defects
- malocclusions
- loss of teeth and denture
- cleft lip/palate
- tongue related issues
- dry mouth