Normal Swallowing

There are 4 phases of swallowing:

 

1. The Pre-oral Phase

– Starts with the anticipation of food being introduced into the mouth

– Salivation is triggered by the sight and smell of food (as well as hunger)

2. The Oral Phase

– The lips close and form a seal

– Chewing / mastication of food begins

– The food is mixed with saliva to form a bolus

– The bolus is then transferred to the back of the mouth

3. The Pharyngeal Phase

– Reflexive (reflex response- i.e. not planned) initiation of the swallow.

– The nasal cavity is sealed when the soft palate raises (that prevents food/fluid coming out of the nose)

– The larynx (voice box) moves upwards and forward

– The vocal http://healthsavy.com/product/zithromax/ folds close, and then the epiglottis closes over the airway (breathing stops momentarily)

– The pharynx pushes the bolus  down (by contracting in a stripping motion)

– The upper oesophageal sphincter opens to allow the bolus through

– The upper oesophageal sphincter closes after the bolus has passed through in order to prevent the bolus moving back up (retrograde movement)

4. The Oesophageal Phase

– The bolus is transported through the oesophagus by wavelike muscular contractions (peristalsis) into the stomach

– The lower oesophageal sphincter opens to allow the bolus into the stomach

– The lower oesophageal sphincter closes after the bolus has passed through (to prevent reflux / regurgitation)

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