Atrophy, Hypertrophy, Metaplasia, Dysplasia

Question 1

What two processes can cause increased growth?

Answer 1

Hypertrophy & hyperplasia

Question 2

Hypertrophy

Answer 2

-increase in size of a tissue caused by an increase in SIZE of the constituent cells
-occurs where cells cannot divide

Question 3

Example of hypertrophy

Answer 3

Skeletal muscles in atheltes/bodybuilders

Question 4

Hyperplasia

Answer 4

-increase in size of a tissue caused by an increase in the NUMBER of the constituent cells
-occurs where cells can divide

Question 5

Example of hyperplasia

Answer 5

BPH
Endometrial hyperplasia

Question 6

Mixed hypertrophy/hyperplasia

Answer 6

-increase in size of a tissue caused by an increase in SIZE & NUMBER of the constituent cells
-occurs where cells can divide

Question 7

Example of mixed hypertrophy/hyperplasia

Answer 7

Smooth muscle cells of uterus in pregnancy

Question 8

Atrophy

Answer 8

-decrease in size of a tissue caused by a decrease in NUMBER or SIZE of constituent cells

Question 9

Example of atrophy

Answer 9

Dementia
Quadriceps muscle following knee injury

Question 10

Metaplasia

Answer 10

-change in differentiation of a cell from one fully-differentiated cell to a different fully-diferentiated cell type
-reversible transformation of mature cells
-adaptive response to injurious stimuli
-usually caused by a consistent change in the environment of an epithelial surface

Question 11

Does metaplasia have pre-malignant potential?

Answer 11

-pure metaplasia has no pre-malignant potential but dysplasia can often arise in metaplastic epithelium

Question 12

3 examples of metaplasia

Answer 12

-Barrett’s oesophagus
-continued cigarette smoke causes change in bronchial epithelium
-acidic environment of vagina during puberty causes change in uterine cervix columnar epithelium

Question 13

Barrett’s oesophagus

Answer 13

-continued acid reflux
-change in oesophageal squamous epithelium
-squamous epithelium -> (glandular) columnar epithelium

Question 14

How does continued cigarette smoke change the bronchial epithelium?

Answer 14

Ciliated columnar epithelium -> squamous epithelium

Question 15

How does the acidic environment of the vagina during puberty change the uterine cervix epithelium?

Answer 15

Columnar epithelium -> squamous epithelium

Question 16

Dysplasia

Answer 16

-imprecise term for the morphological changes seen in cells in the progression to becoming cancer
-premalignant condition
-spectrum = mild, moderate, severe, carcinoma in situ, invasive cancer
-changes can usually be seen by H&E staining down light microscope
-treatment can be given to eradicate the dysplastic epithelium -> prevent development of invasive cancer

Question 17

Term for cells becoming cancerous

Answer 17

Neoplasia

Question 18

Example of dysplasia in bronchi

Answer 18

-bronchial epithelium in cigarette smokers
-metaplasia from ciliated epithelium -> squamous epithelium
-development of dysplasia in the squamous epithelium