Patho Patho #4
Which is an example of cellular metaplasia?
- Precancerous changes visualized on Pap smear.
This answer choice is not correct because precancerous changes on Pap smear are considered dysplasia. Metaplasia is the change from one specific type of cell to another type of cell but is not considered pre-cancer until dysplasia has taken place. Metaplasia may lead to dysplasia.
- Lifting weights leading to increased muscle development.
This answer choice is not correct because the enlargement of muscle cells due to weight lifting is a natural response by the muscles and is referred to as hypertrophy. The muscle cells do not undergo any change other than enlargement.
- Cellular changes in the lungs of a cigarette smoker.
This answer is correct because metaplasia is the change from one type of cell to another type. The airway is lined mostly with pseudostratified columnar epithelium which undergo changes to a completely different type of cell in response to long term exposure to cigarette smoke.
- Skeletal muscle atrophy due to decreased use.
This answer choice is not correct because atrophy is a decrease in size of cells as opposed to the change from one type of mature cell to another.
Metaplasia is defined as the cellular change from one type of cell to another type of cell. Metaplasia may be caused by natural processes or the result of an abnormal stimulus such as mutations that may lead to the development of cancer.
The focus of this question is choosing the best example of cellular metaplasia. Metaplasia is often associated with cellular mutations that can possibly lead to the development of cancer. Long term exposure to cigarette smoke eventually causes changes in the cells in the lungs in which they mutate from one type of cell to another. This is an example of pathologic metaplasia.
Test Taking Tip
When studying cells/genetics in pathophysiology, it is essential to understand cellular terms. This information builds upon itself and a firm understanding, including examples, of each type of cellular change is necessary in order to answer these types of questions correctly.