Oesophagus

The oesophagus is a muscular tube connecting the pharynx to the stomach, hence its name derived from the Greek meaning ‘the way of food’. The combination of gragravityvity and the muscles in the oesophagus moving together in an action called peristalsis allow the food to pass down the tube and into the stomach. There is a sphincter at the junction to the stomach called the oesophago-gastic junction which prevents regurgitation of food in most cases. It is about 26cm long and is located between the wind pipe and the spinal cord.

The oesophagus is made up of four layers the mucosa, submucosa, muscularis externa and adventitia. The mucosa is made up of the epithelium, and the lamina (which contains lymphatic capillaries, blood capillaries and connective tissue) and muscularis mucosa (a double layer of smooth muscle at the bottom half of the oesophagus). The submucosa also contains connective tissue as well as being highly vascular, however its main function is to secrete mucus to help swallow the food, this mucus comes from the oesophageal glands. The muscularis externa is made up of three different sections its top third is entirely skeletal muscle and its bottom third entirely smooth muscle, whilst its middle third is made up of both smooth and skeletal muscle .