The rhythmic contraction and relaxation of muscles of the food-pipe or the oesophagus, called peristalsis, pushes the food to the stomach. Researchers from Indian Institute of Technology, Varanasi have developed a mathematical model of the human oesophagus that could explain the pressure variation in the oesophagus. A detailed understanding of how food is pushed to the stomach can help develop an artificial food-pipe or prosthetic oesophagus, a lifesaving treatment for oesophageal cancer and certain oesophageal disorders.
The new research indicates that when food is swallowed, pressure distribution along the axis of the oesophagus is not uniform as was believed earlier. The peristalsis becomes stronger as food moves from the mouth towards the stomach, resulting in increased pressure at the far end of the oesophagus. The researchers observed that this increased pressure ensures the delivery of food to the stomach, located on the other side of the diaphragm. Experimental observations of a healthy oesophagus revealed the far end of the oesophagus, closer to the stomach, contracted more than the near end, closer to the mouth. The researchers modeled the wall movement of the oesophagus as an increasing amplitude sinusoidal wave, instead of a constant amplitude wave and verified if this model indeed results into an increased pressure at the far end of the oesophagus. The oesophagus undergoes a wave like motion on its wall whose amplitude slightly increases as food moves from the mouth to the stomach. Because of this, the pressure along the length of the oesophagus increases as food moves from the mouth towards the stomach. The pressure is largest when the food needs to be pushed inside the stomach, i.e. at the end of the oesophagus. This improved, realistic model that matches experimental observations, could be a big step in the creation of a prosthetic oesophagus.