Swallowing Phases

Expansion

• Oral (voluntary) - the bolus is formed and pushed back by the tongue
• Pharyngeal (reflex, about 1 second) - the soft palate elevates to close the nasopharynx, the larynx rises and the epiglottis tilts, the vocal cords close, respiration is briefly inhibited, and the upper oesophageal sphincter relaxes
• Oesophageal (reflex, 8 to 10 seconds) - primary peristalsis carries the bolus down; secondary peristalsis clears any residue; the lower oesophageal sphincter relaxes

Control: the swallowing centre in the medulla, with afferents in the glossopharyngeal and vagus nerves, and efferents in cranial nerves V, VII, IX, X and XII.

Localising dysphagia:

• Oropharyngeal: difficulty initiating the swallow, coughing, nasal regurgitation, aspiration. Suggests stroke, motor neurone disease, myasthenia or Parkinson disease
• Oesophageal: food sticking seconds after swallowing. Solids alone suggests a mechanical cause; solids and liquids together suggests a motility disorder such as achalasia