Ans:- Metaplasia is a reversible change in which one adult cell type is replaced by another adult cell type.
- Epithelial metaplasia ————– smokers——-ciliated columnar epithelial cells of the trachea are
replaced by stratified squamous epithelial cells
- Chronic gastric reflux———–the normal stratified squamous epithelium of the lower oesophagus
converts to metaplastic gastric or intestinal-type columnar epithelium—– oesophagal carcinoma.