Cell Injury, Death, and Adaptations in Pathology

Morphologic Changes

Structural cell alterations used for diagnosis.

Clinical Manifestations

Symptoms, signs, and outcomes of diseases.

Homeostasis

Cells adapt to maintain function under stress.

Adaptation

Reversible changes in response to stress.

General Pathology

Study of common disease mechanisms.

Systemic Pathology

Disease changes in specific organs.

Hypertrophy

Increase in cell size, not number.

Hyperplasia

Increase in cell number in dividing cells.

Atrophy

Decrease in size and function of cells.

Metaplasia

Reversible replacement of one cell type with another.

Etiology

Cause of disease, either genetic or acquired.

Pathogenesis

Sequence of events following injury exposure.

Reversible Injury

Cell can return to normal after stress.

Irreversible Injury

Leads to cell death via necrosis or apoptosis.

Necrosis

Unregulated cell death due to injury.

Apoptosis

Programmed cell death with no inflammation.

Caspase Cascade

Enzymatic process leading to apoptosis.

Ischemia

Reduced blood flow causing tissue damage.

Hypoxia

Oxygen deprivation leading to cell injury.

Oxidative Stress

Excess reactive oxygen species causing damage.

Mitochondrial Damage

Impaired ATP production affecting cell survival.

Calcium Influx

Excess calcium activating destructive enzymes.

Chemical Injury

Damage from toxic substances or drugs.

DNA Damage

Caused by radiation, toxins, or ROS.

Membrane Damage

Loss of membrane integrity leading to cell lysis.

Ischemia-Reperfusion Injury

Restoration of blood flow worsening tissue damage.

Myocardial Infarction

Heart tissue death due to oxygen deprivation.

Stroke (CVA)

Brain injury from ischemia-reperfusion.

Acetaminophen Overdose

Toxic metabolite causing oxidative stress.

CCl₄ Toxicity

Free radical formation leading to liver damage.