Oesophagus

Oesophagitis is the inflammation of oesophagus, which is the gullet carrying food to the stomach. In some occasions, the gullet is inflamed, causing obstruction [1]. Most cases of oesophagitis are due to reflux of acid from stomach. The contact time of the ingested material with the oesophageal mucosal lining is short in healthy individuals. However, it is increased in people with swallowing difficulty or in a supine position. The oesophageal lining is composed of stratified squamous epithelium which is relatively impermeable to drugs. The passage of food is lubricated with saliva and mucin coating the oesophagus epithelium. The pH of the oesophagus is about pH6-7, which is equivalent to the pH of the salvia[19], while the pH of the stomach is between 1.5 to 2 [20]. A swallowing action is a voluntary action that is associated with peristaltic wave moving down the oesophagus to clear food and salvia. The typical transit time is around 10-14s. While secondary peristalsis is an involuntary action that occurs in lower part of oesophagus, and it is mainly
There is a valve at the entrance of the stomach, called lower esophageal sphincter (LES). LES closes after food passes through oesophagus. However, if LES does not close all the way, stomach acid can leak out into the oesophagus and cause a heartburn symptom[2]. Besides muscle weakness of LES, there are several factors as well that contribute to acid reflux. Those factors include smoking, drinking alcohol, overweight, wearing tight clothing, eating spicy or fatty foods, aspirin and inflammatory drugs, hiatus hernia and Radiotherapy surgery. Oesophagitis can also be caused by bacterial, viral or fungal infections. This is common in immuno-compromised patients such as AIDS or patients under a high dose of steroid medications. The common causative agents are Candida, herpetic (herpes simplex) virus and