Chapter 2: Cellular Injury, Adaptations, and Maladaptive Changes

Adaptations

Processes like atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia that cells undergo to restore normalcy when stress is removed.

Reversible cell injury

Changes like degenerations, sub-cellular alterations, and intracellular accumulations that can be repaired when stress is eliminated.

Irreversible cell injury

Cell death that occurs when the damage is too severe to be repaired.

Cellular adaptation

Changes in cell function or structure due to disease processes, altered function, or environmental factors.

Causes of cellular adaptation

Factors like damage to the cell membrane, reduced ATP levels, metabolic changes, and pH alterations.

Cellular changes in aging

Decrease in function, structural changes, slowed mitosis, waste accumulation, altered protein synthesis, and decreased collagen and elastin fibers.

Causes of cellular change

Ischemia, inflammation, nutrition imbalance, fluid/electrolyte disturbances, microorganisms, free radicals, physical agents, and genetic defects.

Normal alterations

Hypertrophy (enlargement) or atrophy (decrease) of tissue mass due to various stimuli.

Abnormal alterations

Pathologic changes like hyperplasia, metaplasia, dysplasia, and neoplasia that can lead to cell death.

Endothelial Cell Injury

Damage to the lining of arterial blood vessels due to factors like hypertension, diabetes, smoking, and angiotensin II.

Hypoxia

Most common cause of cell injury due to inadequate oxygen intake, anemia, cardiac arrest, poor circulation, or blood flow obstruction.

Apoptosis

Programmed cell death that eliminates unwanted or damaged cells without adverse effects if occurring at appropriate times.

Necrosis

Cell death caused by injury leading to autolysis, with complications like gangrene caused by Clostridium perfringens infection.