What is metaplasia?

It is replacement of a cell type to another in response to chronic stress and irritation in order to further adapt to this irritation Like squamous metaplasia, although protective to cells, but leads to loss of function (like mucus secretion) and may be malignant (lung cancer) Sometimes can get from squamous to columnar (like in case of gastric reflux Can occur to mesenchyma pathology (bone erosion to soft tissue)