Alterations of Cell Growth

Question 1

Atrophy definition

Answer 1

Reduction in size and/or number of cells in an organ or tissue with accompanying decrease in function

If sufficient numbers involved, entire organ becomes atrophic

Question 2

Causes of atrophy

Answer 2

Decreased workload (think cast)
Loss of innervation (skeletal muscle and polio)
Chronic ischemia (aterhosclerosis)
Loss of endocrine stimulation (menopause and breats)

Question 3

COnsequences of atrophy

Answer 3

Decrease or loss of functions
Smaller organ is unable to function
Think hard to walk after cast or memory impairmnet

Question 4

Aplasia

Answer 4

Total absence of organ due to failure or development in utero

Question 5

Hypoplasia

Answer 5

Organ present but abnormlally small

Question 6

Hypertrophy def

Answer 6

increase in SIZE of cells within organs/tissues with overall increase in size of organ

Question 7

Causes of hypertrophy

Answer 7

Demand for increase in function of organ tissue (LV hypertrophy from hypertension)
Hormonal stimulation (uterus enlargement during pregnancy because estrogen)

Question 8

Hyperplasia def

Answer 8

increase in number of cells

Only if labile or stable cells

Question 9

Physiologic hyperplasia

Answer 9

Hormonal - enlargement of female breasts at puberty because of estrogen
Compensatory - half of liver removed, reminaing half undergoes hyperplasia

Question 10

Pathologic hyperplasia

Answer 10

Part of a disease

Endometrial hyperplasia is abnormal proliferation of endometrial cells that causes bleeding and precurosr to cncer

Question 11

Metaplasia def

Answer 11

Replacement of one type of tissue with another

Question 12

Metaplasia cause

Answer 12

Original tissue cannot cope with threat…metaplasia is a protective adaptation
Example is cigarette smoke causing loss of columnar cells replaced with squamous cells

Question 13

Consequences of metaplaisa

Answer 13

Replacement tissue might not function as well

Squamous cells will increase risk of infection…also risk of cancer

Question 14

Metaplasia time

Answer 14

Reversible…if smoker quits, columnar cells return

Question 15

Metaplasia nomenclature

Answer 15

After the substituted tissue (squamous metaplasia)

Question 16

Dysplasia features

Answer 16

Disordered cell growth - disorganized

Pelomorphism - variability…also increase in number undergoing mitosis

Question 17

Classification of dysplasia

Answer 17

Mild - Lower 1/3
Moderate - Lower 2/3
Severe - almost full thickness
CIS - carcinoma in situ when abnormal cells occupy full thickness of the epithelium but have NOT broken through yet
Once brekathrough, carcinoma

Question 18

Consequence of dysplasia

Answer 18

Precursor to cancer…most cancers arise from dysplastic tissue

Question 19

Generation of cancer hypothesis

Answer 19

Normal to mild to moderate to severe to CIS to invasive

Question 20

Causes of dysplasia

Answer 20

HPV - uterine cervix
Cigarette smoke - squamous dysplasia of bronchi
Often unknown

Question 21

Final points of dysplasia

Answer 21

Reversible, esepcailly in mild and moderate

Still under control of GFs and ECM proteins