part of alimentary canal esophagus A muscular tube that in humans is about nine inches (23 centimeters) long and passes from the pharynx down the neck between the trachea and the spinal column and behind the left bronchus where it pierces the diaphragm slightly to the left of the middle line and joins the cardiac end of the stomach. BTO:0000959 BrendaTissueOBO gullet oesophagus