Pathoma: Growth Adaptations

Question 1

Adaptation

Answer 1

increase, decrease, or change in stress on an organ

Question 2

Hyperplasia

Answer 2

increase in number of cells

production of new cells from stem cells

Question 3

Hypertrophy

Answer 3

increase in size of cells
involves gene activation, protein synthesis, and production of organelles
increased production of cytoskeleton (proteins)

Question 4

Permanent tissues

Answer 4

do NOT have stem cells
can only undergo hypertrophy
cardiac myocytes
skeletal M.
nerve

Question 5

What can pathologic hyperplasia progress to?

Answer 5

dysplasia and cancer
endometrial hyperplasia–>carcinoma
EXCEPTION: benign prostatic hyperplasia (no risk for cancer)

Question 6

Atrophy

Answer 6

decrease in stress–>decrease in organ size
occurs via decrase in size and number of cells
occurs via apoptosis- decrease in cell number

Question 7

2 ways cells decrease in size in atrophy

Answer 7

ubiquitin-proteosome degradation of cytoskleteon

autophagy of cell components

Question 8

Metaplasia

Answer 8

change in stress–>change in cell type

Question 9

What kind of epithelium does metaplasia normally involve?

Answer 9

surface epithelium

Question 10

Why does metaplasia occur?

Answer 10

to adapt cells to be better able to handle new stress

Question 11

Example of metaplasia

Answer 11

Barrett’s esophagus: esophagus normally lined by squamous epithelium but changes to mucous secreting columnar epithelium like in stomach when acid in stomach goes into the esophagus

Question 12

How does metaplasia occur?

Answer 12

reprogramming of stem cells

Question 13

Is metaplasia reversible?

Answer 13

Yes, by removal of the driving stressor

Question 14

Can metaplasia progress?

Answer 14

Yes, to dysplais and cancer

EXCEPTION: apocrine metaplasia (fibrocytic changes in the breast)

Question 15

What deficiency can lead to metaplasia?

Answer 15

Vitamin A
night blindness
immune system unable to mature
keratomalacia–>thickening of the conjunctiva of the eye

Question 16

What tissues can undergo metaplasia?

Answer 16

mesenchymal tissues
bone, blood vessels, cartilage, fat
connective tissues

Question 17

Myositis ossificans

Answer 17

inflammation of skeletal muscle due to trauma that converts it to bone
looks similar to osteocarcinoma but the bone next to it is normal and there is a distinct separation of the bony metaplasia from the normal bone

Question 18

Dysplasia

Answer 18

disordered cell growth

proliferation of precancerous cells

Question 19

What leads to dysplasia?

Answer 19

longstanding pathologic hyperplasia (endometrial hyperplasia) or metaplasia (Barrett’s esophagus)

Question 20

Is dysplasia reversible?

Answer 20

Yes, with alleviation of inciting stress

if stress persists, can lead to carcinoma (irreversible)

Question 21

Aplasia

Answer 21

failure of cell production during embryogenesis

Ex: unilateral renal agenesis

Question 22

Hypoplasia

Answer 22

decrease in cell production during embryogenesis
results in relatively small organ
Ex: streak ovary in Turner Syndrome