hypertrophy hyperplasia atrophy metaplasia dysplasia

Question 1

Describe hypertrophy

Answer 1

increase in the size of an organ due to increase in the size of its constituent cells

Question 2

Where does hypertrophy occur?

Answer 2

in organs where cells cannot divide

Question 3

give examples of hypertrophy

Answer 3

skeletal muscle in athletes/bodybuilders

Question 4

describe hyperplasia

Answer 4

increase in the size of an organ due to increase in the number of its constituent cells

Question 5

where does hyperplasia occur?

Answer 5

in organs where cells can divide

Question 6

give examples of hyperplasia

Answer 6

benign prostatic hyperplasia, endometrial hyperplasia

Question 7

describe mixed hypertrophy/ hyperplasia

Answer 7

increase in the size of an organ due to increase in size and number of its constituent cells

Question 8

where does mixed hypertrophy/hyperplasia occur?

Answer 8

occurs in organs where cells can divide

Question 9

give examples of mixed hypertrophy/hyperplasia

Answer 9

example - smooth muscle cells of the uterus during pregnancy

Question 10

describe metaplasia

Answer 10

change in cell differentiation from one fully-differentiat- ed type to another fully-differentiated type

Question 11

what usually causes metaplasia?

Answer 11

Usually caused by a consistent change in the environ- ment of an epithelial surface

Question 12

Give examples of metaplasia

Answer 12

1. Bronchial epithelium from ciliated columnar epithelium to squamous epithelium in the face of continued cigarette smoke.
2. Oesophageal squamous epithelium to glandular epithelium in continued acid reflux from the stomach (Barrett’s oesophagus).
3. The uterine cervix from columnar epithelium to squamous epitheli- um at puberty when it is exposed to the acidic environ- ment of the vagina

Question 13

How can you spot the difference between pure metaplasia and dysplasia in metaplastic epithelium?

Answer 13

has no premalignant potential

Question 14

describe dysplasia

Answer 14

an imprecise term for the morphological changes that may be seen in cells (often epithelium) in the progression on to development of cancer (neoplasia)

Question 15

what is dysplasia usually defined by?

Answer 15

features seen on haematoxylin and eosin staining down the light microscope (i.e. usual histopathology examination).

Question 16

Give an example of dysplasia

Answer 16

Bronchial epithelium in cigarette smokers:
metaplasia from ciliated to squamous epithelium, then development of dysplasia in the squamous epithelium

Question 17

why is the identification of dysplasia useful?

Answer 17

treatment can be given to eradicate the dysplastic epithelium and so prevent the development of invasive cancer.