Chapter 2: Cellular Injury, Adaptations, and Maladaptive Changes

Vocabulary flashcards covering core terms, concepts, cellular adaptations, mechanisms of cell injury, and tissue degradation pathways from Chapter 2.

Etiology

The original cause of a cell alteration or disease.

Etiologic Agents

Factors or causes that produce cell alteration or disease, such as infection or trauma.

Histology

The microscopic study of tissue.

Biopsy

A tissue sample collected for histological analysis.

Autopsy

An examination of tissue from deceased organisms.

Pathognomonic Changes

Unique, identifying disease presentations, such as a crater-like formation in the stomach indicating a peptic ulcer.

Atrophy

A cellular adaptation in which cells revert to a smaller size, such as muscle shrinkage caused by paralysis.

Hypertrophy

An increase in individual cell size, such as skeletal muscle enlargement from strength training.

Physiological Hypertrophy

Cell enlargement accompanied by adequate supporting tissues, such as cardiac cell growth in response to exercise training.

Pathological Hypertrophy

An increase in cell size without a proportional increase in supporting structures, such as cardiac enlargement due to hypertension.

Hyperplasia

An increase in the number of cells capable of mitosis, which can occur due to hormonal stimulation (e.g., estrogen in pregnancy) or maladaptive compensation.

Keloid

An elevated, hyperplastic scar formation resulting from excessive cell proliferation during wound healing.

Metaplasia

The replacement of one cell type with another through genetic reprogramming to ensure cell survival in response to chronic irritation.

Barrett's Esophagus

A metaplastic condition occurring in GERD where flat, squamous epithelial esophageal cells transition into columnar, stomach-like cells.

Dysplasia

Deranged cellular growth resulting in cells that vary in size, shape, and organization compared to normal cells, often caused by chronic inflammation or precancerous conditions.

Neoplasia

New, disorganized, uncoordinated, and uncontrolled cell growth that is cancerous and often forms a tumor.

Benign Neoplasm

A tumor composed of well-differentiated cells that resemble normal cells, have well-defined borders, and do not metastasize.

Malignant Neoplasm

A tumor composed of poorly differentiated cells that appear distinct from healthy cells, have poorly defined borders, and carry an increased likelihood of metastasis.

$\text{Na}^+/\text{K}^+$ Pump Dysfunction

Loss of active sodium-potassium transport across the cell membrane leading to disruption of the electrochemical gradient and cellular swelling.

$\text{Ca}^{++}$ Pump Dysfunction

Failure to clear intracellular calcium ions, leading to calcium accumulation and cell degeneration.

Hypoxia

Diminished oxygen supply to cells, serving as the most common cause of cell injury and driving cells into anaerobic metabolism with elevated lactic acid levels.

Free Radicals

Reactive oxygen species containing unpaired electrons formed during aerobic metabolism that interact with and disrupt cell plasma membranes.

Oxidative Stress

A condition that occurs when protective cellular mechanisms, such as superoxide dismutases, are overwhelmed by free radicals.

Endothelium

An active cellular layer lining the interior of blood vessels that secretes VEGF, nitric oxide (NO), and endothelin, but is vulnerable to injury from hypertension, hyperglycemia, free radicals, and hyperlipidemia.

Aneurysm

A weakened area of an arterial wall that is prone to rupture, often caused by high shearing forces from hypertension.

Atherogenesis

The process of atherosclerotic plaque formation initiated by endothelial injury, leading to LDL-C deposition, macrophage accumulation, and foam cell formation.

Apoptosis

Programmed, organized cell death involving cell shrinkage, chromatin condensation, and phagocytosis of apoptotic bodies without causing inflammation.

Necrosis

Irreversible cell death resulting from injury, characterized by cellular swelling, membrane disintegration, lysosomal activation, autolysis, and inflammation.

Infarction

Ischemic necrosis of tissue resulting from prolonged loss of blood supply, such as myocardial infarction where cardiac proteins are released into circulation.

Gangrene

Tissue necrosis resulting from prolonged ischemia and infarction, which can involve Clostridium perfringens emitting identifiable gas (gas gangrene).

Human Umbilical Cord–Mesenchymal Stem Cells (HUC-MSCs)

Stem cells utilized in regenerative medicine that possess low immunogenicity and a high ability to proliferate and differentiate.