Cell Injury I

Question 1

What is the difference between etiology and pathogenesis?

Answer 1

Etiology is the origin of a disease (why a disease develops) and pathogenesis refers to the steps in the development of disease (how a disease develops).

Question 2

What are the five principal cellular adaptive responses?

Answer 2

Hypertrophy, hyperplasia, atrophy, metaplasia, and dysplasia.

Question 3

What is the difference between hypertrophy and hyperplasia?

Answer 3

Hypertrophy is the increase in cell size whereas hyperplasia is an increase in cell number.

Question 4

What are two possible causes of hypertrophy?

Answer 4

Increased functional demand and growth factor/hormonal stimulus.

Question 5

What are the two types of physiologic hyperplasia? Name an example of each.

Answer 5

1. Hormonal - female breast gland growth during pregnancy.

2. Compensatory - liver regeneration following resection.

Question 6

Define atrophy. By which main mechanism does this occur?

Answer 6

Shrinkage in the size of the cell by the loss of cell substance. Occurs by decreased protein synthesis and increased protein degradation.

Question 7

Define metaplasia. Is it reversible?

Answer 7

A reversible change in which one adult cell type is substituted by another type.

Question 8

Describe the pathogenesis of metaplastic cells.

Answer 8

Stem cells differentiate along a different pathway (rather than mature cells changing).