* Normal cells have a fairly narrow range of
function or steady state: Homeostasis.
• Excess physiologic or pathologic stress may
force the cell to a new steady state:
* Too much stress exceeds the cell’s adaptive
It is modification of cell morphology and function
to achieve a new steady but altered state,
preserving the viability of cells, which include
- Hypertrophy is an
increase in the size
of organ by + size
of its individual
cells, in response to
a stimulus or injury.
-Is an increase in organ size by increase of
number of its cells, in response to a
stimulus or persistent cell injury.
C/p: mass - bleeding
Lung: atrophic emphysema
Heart: brown atrophy
Local: decrease size &
fibrous or fibrofatty
-A reversible change in which one mature/adult cell
type (epithelial or mesenchymal) is replaced by
another mature cell type of the same category.
- A/E: Chronic irritation- avitminosis A- genetic
- Types: Epithelial, C.T, Mesothelial
Causes: It is an adaptive mechanism by which the
cells less sensitive to stress are replaced by
other cell type more capable to withstand the
Types: - Squamous metaplasia.
- Glandular metaplasia.
- Mesothelial metaplasia.
It may be precancerous especially epithelial
metaplasia although it is reversible