Atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia

Question 1

What is hypertrophy?

Answer 1

Increase in cell size without cell division

Question 2

Examples of hypertrophy

Answer 2

Skeletal muscle and left ventricle in athletes
Uterine smooth wall in pregnancy and puberty

Question 3

What is hyperplasia?

Answer 3

Increase in cell number by mitosis, only in dividing cells

Question 4

Examples of hyperplasia

Answer 4

Bone marrow cells in high altitude
Prostate smooth muscle
Endometrial hyperplasia

Question 5

What is atrophy?
What is it a response to?

Answer 5

Decrease in organ/tissue size by reduction in cell size or number
Response to a decreased requirement for the function of a tissue or organ

Question 6

Examples of atrophy

Natural and disease

Answer 6

Natural - involution of wolffian/mullerian duct in F/M
Disease - muscle atrophy due to loss of innervation
Gut and pancreas atrophy due to malnutrition
Cerebral atrophy in dementia

Question 7

What is metaplasia?
What is it in response to?

Answer 7

A change in differentiation from one fully differentiated cell type to another
Response to alterations in the cellular environment

Question 8

Examples of metaplasia

Answer 8

Barrett’s oesophagus - squamous epithelium to columnar in oesophagus
Ciliated respiratory epithelium of trachea and bronchi changes to squamous epithelium in smokers

Question 9

What is dysplasia?

Answer 9

Morphological changes in cells in progression to becoming cancer