Question

Describe the anatomy and physiology of deglutition. How are food and water routed in the right directions (and prevented from going the wrong ways)?

Answer 1

Answer-

Deglutition means the transportation of food and liquid from mouth to the stomach. The structure involves the tongue, hard and soft palate, pharyngial muscles, esophagus and gastroesophageal junction.

There are three phases of deglutition...

1. Oral- this includes gathering of food, movement in oral cavity, mastication and formation of boluses of ingesta at the base of the tongue.

2. Pharyngial- The presence of bolus gathered at the base of the tongue triggers the sequence of reflexes which is known as swallowing which propels the ingesta from pharynx to the esophagus. The glossopharyngial nerve and the pharyngial branch of vagus innervate the pharynx and larynx and there afferent and efferent pathways are coordinated in the swollowing centre in the brain stem.

3. Oesophagus- waves of peristalises convey the ingesta along the oesophagus to the stomach.