He esophagus is the sector of the digestive tube that develops from the pharynx until the stomach . The term comes from medieval Latin oesophagus, in turn derived from the Greek oisophágos.
The esophagus is present in vertebrates and also in invertebrates. In the case of human being , measures near 25 centimeters and its extension goes from the seventh or sixth cervical vertebra to the eleventh thoracic vertebra.
This part of the digestive system is crossed by food, which enters through the mouth , go through the pharynx , cross the esophagus and they arrive at stomach . In this process, the esophagus has an active participation, as its walls contract to boost the advance of food.
In order for the food to access the esophagus, the opening of the upper esophageal sphincter . Then the peristalsis (the waves of muscle contractions) that push it down until it slides through the lower esophageal sphincter and thus enter the stomach .
It is important to mention that, if the esophagus is at rest, the sphincters are kept closed to prevent Reflux of gastric acid and food from the stomach to the mouth. With the swallowing , instead, they open. Aging causes the contractions of the esophagus and sphincter pressure to lose strength, with which the propensity to suffer from reflux grows with age.
He esophagus cancer , he Barrett's esophagus and the esophageal achalasia are some of the disorders and diseases that can be registered in this region of the body . Among the symptoms that help detect them appear the dysphagia (trouble swallowing) and the odynophagia (pain when swallowing).