oesophagus (esophagus), from the Greek for gullet, refers to the muscular tube, with a mucus-secreting lining, that leads from the mouth via the pharynx, down through the neck and the thorax, and through the diaphragm to the stomach. In the neck it lies behind the air passages — the lower end of the larynx and the upper part of the trachea. In the thorax, it continues behind the trachea and the heart, to pass into the abdominal cavity through a gap in the muscle of the diaphragm; less than an inch below this, it opens into the stomach. When swallowing occurs, food is pushed into the top of the oesophagus, and is then propelled onwards by waves of circular muscle relaxation below it and of contraction above it: the peristalsis that occurs throughout the gut. This process can if necessary defeat gravity; food, and even liquids, can be swallowed even standing on one's head, though clearly this is not generally attempted except as a remarkable demonstration. Muscle encircling the oesophagus at the top and bottom provides sphincters that, respectively, prevent air being sucked in during inhalation, and regurgitation of stomach contents.

Stuart Judge

e·soph·a·gus / iˈsäfəgəs/ • n. (pl. -gi / -ˌgī; -ˌjī/ or -gus·es) the part of the alimentary canal that connects the throat to the stomach; the gullet. In humans and other vertebrates it is a muscular tube lined with mucous membrane.DERIVATIVES: e·soph·a·ge·al / iˌsäfəˈjēəl/ adj.

oesophagus (gullet) The section of the alimentary canal that lies between the pharynx and the stomach. It is a muscular tube whose function is to transfer food to the stomach by means of wavelike contractions (peristalsis) along its length.

oesophagus (gullet) Muscular tube, part of the alimentary canal (or gut), which carries swallowed food from the throat to the stomach. Food is moved down the lubricated channel by the wave-like movement known as peristalsis.

oesophagus The part of the alimentary canal that lies between the pharynx and the stomach.