Cell Adaptation, Injury, and Death

Comprehensive vocabulary flashcards covering cellular adaptation, types of cell injury, patterns of necrosis, apoptosis, and cellular aging based on the lecture transcript.

Adaptations

Reversible functional and structural responses to more severe physiologic stresses and some pathologic stimuli, during which new but altered steady states are achieved, allowing the cell to survive and continue to function.

Hypertrophy

An increase in the size of cells, resulting in an increase in the size of the organ, caused by the synthesis of more structural components rather than new cells.

Hyperplasia

An increase in the number of cells in an organ or tissue, usually resulting in increased mass of the organ or tissue.

Atrophy

Reduced size of an organ or tissue resulting from a decrease in cell size and number.

Metaplasia

A reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type better able to withstand an adverse environment.

Hypoxia

A deficiency of oxygen which causes cell injury by reducing aerobic oxidative respiration.

Reversible cell injury hallmarks

Reduced oxidative phosphorylation (depletion of ATP) and cellular swelling caused by changes in water influx.

Necrosis

A form of cell death resulting from denaturation of intracellular proteins and enzymatic digestion of the lethally injured cell.

Myelin figures

Large, whorled phospholipid masses derived from damaged cell membranes that may replace dead cells.

Karyolysis

The fading of the basophilia of the chromatin due to degradation by endonucleases.

Pyknosis

Nuclear shrinkage, characterized by increased basophilia; it is also seen in apoptotic cell death.

Karyorrhexis

A nuclear change where the pyknotic nucleus undergoes fragmentation.

Coagulative necrosis

A form of necrosis in which the architecture of dead tissues is preserved for at least some days; a localized area of this is called an infarct.

Liquefactive necrosis

Characterized by digestion of dead cells, resulting in a liquid viscous mass (pus); commonly seen in focal bacterial or fungal infections and hypoxic death in the CNS.

Gangrenous necrosis

A clinical term usually applied to a limb that has lost its blood supply and undergone coagulative necrosis; can be 'dry' or 'wet'.

Caseous necrosis

Encountered most often in foci of tuberculous infection; characterized by a friable white, 'cheeselike' appearance.

Fat necrosis

Focal areas of fat destruction, such as in breast tissue after mechanical trauma.

Fibrinoid necrosis

A special form of necrosis seen in immune reactions involving blood vessels, characterized by bright pink and amorphous deposits of immune complexes and leaked fibrin.

Apoptosis

A tightly regulated 'suicide program' where cells activate enzymes to degrade their own DNA and proteins; characterized by chromatin condensation and apoptotic bodies.

Autophagy

A process in which a cell eats its own contents as a survival mechanism during nutrient deprivation.

Dystrophic calcification

The abnormal tissue deposition of calcium salts in areas of necrosis, such as in advanced atherosclerosis.

Metastatic calcification

Calcium salt deposition occurring in normal tissues whenever there is hypercalcemia, affecting tissues like the gastric mucosa, kidneys, and lungs.

Cellular aging

A progressive decline in cellular function and viability caused by genetic abnormalities and cumulative cellular and molecular damage.

$$\text{Marasmus}$$

Profound protein-calorie malnutrition associated with the use of skeletal muscle as a source of energy.

$$\text{Barrett esophagus}$$

A condition resulting from acid reflux disease where squamous epithelium undergoes metaplasia to a columnar type.