Role and function of the oesophagus – functionally, the oesophagus can be divided into three parts: the upper sphincter, the lower sphincter and the tubular section between the two.
When breathing in, the upper sphincter prevents air from entering the oesophagus, while during swallowing it relaxes, helping the mouthful to enter the tubular section.
The tubular section is responsible for moving swallowed saliva and food onwards.
The lower sphincter prevents acidic, sometimes bile-containing stomach contents from flowing back into the oesophagus, and helps move the mouthful on into the stomach.
