What Is Metaplasia?
Metaplasia refers to the transition of a particular type of tissue into another type of tissue. It can be normal, as for example when cartilage hardens into bone, or abnormal, as in the case of Barrett’s esophagus, a condition in which the lining of the esophagus is changed by prolonged exposure to stomach acid. When metaplasia is abnormal, it can be a cause for concern, as it usually indicates that some sort of medical problem is occurring. Abnormal metaplasia usually occurs in response to a stress or stimulus which encourages more delicate cells to be replaced by hardier cells. The epithelial lining of the internal organs of the body, for example, can change from columnar to squamous in response to stress, as is seen in cervical metaplasia. This process is also usually reversible, with cells reverting if the cause of the metaplasia is addressed. Every cell type in the body is very specific and designed for a particular purpose. When metaplasia occurs where it is not supposed to, this
