Hypertrophy, hyperplasia, atrophy, metaplasia and dysplasia Flashcards
What is hypertrophy?
- Increase in size of a tissue caused by an increase in size of the constituent cells
- Usually occurs in organs where cells can’t divide
Where is an example of where hypertrophy occur?
Skeletal muscle
What is hyperplasia?
- Increase in size of a tissue caused by an increase in number of the constituent cells
- Where cells can divide
What are examples of of hyerplasia?
- Benign prostatic hyperplasia: smooth muscle cells have divided
- Endometrial hyperplasia: too much oestrogen compared to progesterone
- Endothelial hyperplasia
- Neuronal hyperplasia: peripheral nerves outside CNS can divide
What is atrophy?
Decrease in size of a tissue caused by a decrease in number of the constituent cells or a decrease in their size
What are examples of atrophy?
- Cerebral atrophy in dementia
- Muscle atrophy
What is metaplasia?
Change in differentiation of a cell from one fully differentiated type to a different fully differentiated type
What is an example of metaplasia?
- Cilia can be damaged by air pollution (ciliated columnar epithelium → squamous epithelium) more prone to infection, no cilia to waft out of lungs
- Barret’s oesophagus
What is dysplasia?
Imprecise term for the morphological changes seen in cells in the progression to becoming cancer
What is an example of dysplasia?
In bronchi, metaplastic cells can become dysplastic
What happens after dysplasia occurs?
Becomes carcinoma
What are developmental abnormalities that are referred to as dysplasia?
- Focal cortical dysplasia
- Hip dysplasia
