Hypertrophy, Hyperplasia, Atrophy, Metaplasia, Dysplasia

Question 1

What is hypertrophy?

Answer 1

Increase in size of a tissue caused by an increase in size of constituent cells - the size of the cell/tissue/organ increases without an increase in the number of cells (so without cell division)

Question 2

What is hyperplasia?

Answer 2

Increase in size of a tissue caused by an increase in number of constituent cells - increased growth is the result of an increase in number of cells by mitosis

Question 3

What is atrophy?

Answer 3

Decrease in size of a tissue caused by a decrease in number of the constituent cells or a decrease in their size (don’t have hyper/hypo it’s just atrophy)

Question 4

What is metaplasia?

Answer 4

Change in differentiation of a cell from one fully-differentiated type to a different fully differentiated type - the reversible transformation of one mature cell type into another fully differentiated cell type
- An adaptive response to injurious stimuli
E.g smokers = cilliated respiritory epithelium of the trachea to squamous epithelium
E.g squamous epithelium of the oesophagus due to prolonged exposure to stomach acid to columnar epithelium = Barrett’s oesophagus

Question 5

What is dysplasia?

Answer 5

Imprecise term for the morphological changes seen in cells in the progression to becoming in cancer - a premalignant condition characterised by increased growth, cellular atypical and decreased differentiation
Differentiated cell type -> poorly differentiated cell type
- not quite cancer but could/on way to becoming cancer