Cell adaptations

What are the ways cells respond to stress?

Atrophy

Hypertrophy

Hyperplasia

Metaplasia

Dysplasia

Atrophy

Shrinkage in the size of the cell by loss of structural components

Hypertrophy

Increased size of cells and the organ

Hyperplasia

Increase in the number of cells in an organ or tissue

Metaplasia

Reversible change in which one adult cell type is replaced by another cell type

This is in response to stress in which a cell that is sensitive to that stress is replaced by another cell type that is better able to survive the adverse environment

The mechanism is thought to be reprogramming of tissue stem cells to differentiate along a new pathway

Columnar to squamous epithelium

Dysplasia

This is disordered growth of epithelial cells that are abnormal but not malignant.

Cellular and nuclear pleomophism, typically in the form of abnormally large, hyperchromatic nuclei

Abnormal mitotic activity/failure to mature

Architectural disarray

NOT necessarily cancer bound, just an increased rate.

Fatty change

Lipid in macrophages

Foam cells - atherosclerosis

Lipid in parenchyma cells

Alcholic fatty liver

Intracellular proteins

Kidney proximal tubules - hyaline droplets

Plasma cells: russell bodies

Alchoholic hyaline

Alcoholic hyaline

Seen in liver cells of people with alcohol abuse disorder

Tangled skeins or cytokeratin intermediate filaments and other proteins

Eosinophilic cytoplasmic inclusions

Pigments

Endogenous pigments

Lipofuscin

Melanin

Hemosiderin

Iron overload

Hemosiderosis (phagocytic cells) no tissue damage

Hemochromatosis: parenchumal cells with tissue damage

Metastatic calcification

Deposition of Ca in normal tissue due to hypercalcemia

Interstital tissues of blood vessels, kidneys, lungs, and gastric mucosa

Dystrophic calcifiation

Deposition of Ca salts in nerotic tissues

Intra, extra, or both

Heterotrophic bone may form with time