Physiology in Dysphagia (ISS) Flashcards
(22 cards)
Function of deglutition (swallowing)?
Process which moves food/liquid from the the mouth, through the pharynx and oesophagus, to the stomach; this takes 20 secs
Requirements for normal swallowing?
Neuromuscular contraction (voluntary and involuntary control)
Absence of mechanical obstruction
3 phases of swallowing?
- Oral
- Pharyngeal (shortest phase - 1 second)
- Oesophageal (8-20 seconds)
Control of the oral phase of swallowing?
VOLUNTARY and involves high cortical centres, muscles and cranial nerves V, VII and XII
Other structures involved with the oral phase of swallowing?
Teeth - chewing of food
Lips - containment of food
Palate - allows simultaneous breathing and chewing, as it separate the oral and nasal cavities
Salivary glands - produce saliva to moisten food
Tongue - forms food bolus and pushes it posteriorly, into the pharynx
Abnormalities that can affect the oral phase of swallowing?
Abnormalities of: Mouth Salivary secretions Muscles of mastication Neurological disorders, e.g: cerebral cortex or cranial nerves
Control of the pharyngeal phase of swallowing?
Involuntary; it is controlled by brain stem centres and CN IX and X
Responses are initiated by food pressure on the pharyngeal pressure receptors; there is an afferent impulse to the swallowing centre in the medulla of the brain stem
Common functions of the: Soft palate Tongue Uvula ?
Prevent entry of food into the nasal passages as:
Soft palate rises
Tongue presses against the hard palate
Uvula presses against the back of the throat
Common functions of the: Larynx Epiglottis Vocal chords Swallowing centre (brain) Pharyngeal muscles ?
Prevent entry of food into the trachea:
Larynx is elevated
Epiglottis tilts
Vocal chords adduct across the glottis
Swallowing centre inhibits the resp centre
Pharyngeal muscles contract and forces bolus into the oesophagus
Function of the upper oesophageal sphincter?
Opens to allow food into the oesophagus
Control of the oesophageal phase of swallowing?
Involuntary; swallowing centre in the medulla is involved with closure of the UOS, once the bolus has entered the oesophagus
Process of moving food from the pharynx to the stomach?
Bolus moves by peristaltic contractions, initiated by the swallowing centre in the medulla (via CN X)
Upper oesophagus - skeletal muscle contractions
Lower oesophagus - smooth muscle in distal oesophagus
LOS opens to allow passage and closes to prevent reflux
Causes of dysphagia?
Lack of normality of muscles, cortical centres, brain stem centres and CN V, VII, IX, X and XII
Mechanical obstruction
Abnormal dentition and salivary function
Characteristics of oropharyngeal (transit) dysphagia?
More difficulty swallowing LIQUIDS than solids. as liquid is more like to enter resp tract
Examples of causes of oropharyngeal dysphagia?
Tonsillitis, pharyngitis
Stroke Multiple sclerosis Parkinson's disease Motor neuron disease Myasthenia gravis
Muscular dystrophy
Xerostomia (dry mouth - abnormal saliva production)
Obstruction by tumour/foreign body
Symptoms of oral dysphagia?
Difficulty chewing/inadequately chewing food
Retention of food in the mouth
Sticking or pocketing of food in the mouth
Difficulty getting food to the back of the throat
Stranded phlegm
Drooling
Symptoms of pharyngeal dysphagia?
Coughing while or immediately after eating or drinking
Nasal regurg of food & drinks
Gurgly sounding voice during/after eating/drinking
Sticking of food in the back of the throat
Aspiration - chest problems
Describe oesophageal dysphagia
Inability to swallow solid foods and often described as food sticking before it reaches the stomach
Onset of symptoms is several secs AFTER swallowing begins
What is dysphagia equally affecting liquids and solids from the outset likely to be?
Neuromuscular, e.g: achalasia
What is dysphagia initially for solids likely to be?
Mechanical obstruction (intrinsic/extrinsic):
Intermittent, non-progressive oesophageal dysphagia to solids likely has a benign cause, e.g: GORD
Rapidly progressive oesophageal dysphagia likely has a malignant cause, esp. if assoc. with weight loss
Symptoms of oesophageal dysphagia may include?
Sticking of food, e.g: in mid-chest or at the level of the epigastrium
Vomiting
Symptoms may occur several seconds after initiation of swallowing
History of heartburn and/or reflux
Chest symptoms caused by ASPIRATION
Weight loss
Ix for dysphagia?
Blood tests, e.g: FBC, LFTs and U&Es
CXR
Endoscopy (look for obstructive oesophageal causes)
CT scan
Ba swallow or video fluoroscopy (assess oropharyngeal phases of swallowing)
