What are the stages of deglutition?

Answer 1

Deglutition, or swallowing, can be divided into three stages. The oral, pharyngeal and oesophageal stages.

Oral stage - the bolus of food is prepared --> the apex of the tongue presses on the palate --> rapid contraction of mylohyoideus and extrinsic muscles of the tongue propel the food (bolus) to the pharynx.

Pharyngeal stage - the bolus hits the pharynx and triggers reflexes (from this point it is no longer voluntary) --> the soft palate is raised, the glottis closed and the pharynx shortened --> pharyngeal constrictors move bolus into the oesophagus

Oesophageal stage - peristalsis moves the bolus to the stomach

Answer 2

Mouth, nasopharynx, and larynx are blocked; upper esophageal sphincter relaxes to open esophagus; food moves through esophagus by pressure gradients created by peristalsis.