In this article we will discuss about the structure of oesophagus with the help of a suitable diagram.
The mucous membrane of it consists of stratified squamous epithelium. Just under the mucous membrane, there is another very thin layer of plain muscle, called museularis mucosae. Then comes the inconspicuous submucous coat.
It consists of collagenous and elastic fibres. Together with the museularis mucosae, the submucous layer forms numerous longitudinal folds which result in the irregular form of the lumen in cross-section.
During swallowing of food, these folds are smoothed out. Outside this, remains the muscular coat consisting of two layers; the outer longitudinal and the inner circular layer. In the upper third of oesophagus (Fig. 9.18) the muscles are voluntary, in the middle third both voluntary and involuntary, in the lower third only plain muscle is found. Lastly comes the outermost covering consisting of fibrous tissue, called the tunica adventitia.
Functions:
It receives food from the pharynx and passes it on to the stomach by a series of peristaltic contraction.
