Cellular Adaptation and Cell Necrosis – Key Vocabulary

A comprehensive set of vocabulary flashcards summarizing key terms and definitions from the lecture on cellular adaptation, dysplasia, anaplasia, necrosis, gangrene, and pathologic calcifications.

Cellular Adaptation

Reversible changes in size, number, phenotype, metabolic activity, or function of cells in response to prolonged or exaggerated stimuli.

Physiologic Adaptation

Normal, programmed cellular change that occurs to meet everyday functional demands (e.g., uterine enlargement in pregnancy).

Pathologic Adaptation

Cellular change triggered by disease or harmful stress that may progress to injury if the stimulus persists (e.g., LV hypertrophy in hypertension).

Atrophy

Decrease in the size of a tissue, organ, or body part owing to reduction in individual cell size; may be physiologic (thymic involution) or pathologic (ischemic kidney).

Hypertrophy

Increase in tissue or organ size due to enlargement of existing cells; occurs physiologically in skeletal muscle or pathologically in hypertensive heart.

Hyperplasia

Adaptive increase in the number of cells leading to tissue enlargement, such as endometrial hyperplasia or colonic polyps.

Hypertrophy with Hyperplasia

Simultaneous increase in cell size and number, exemplified by uterine smooth muscle in pregnancy or prostate enlargement (BPH).

Metaplasia

Reversible substitution of one mature cell type by another better suited to withstand stress (e.g., squamous metaplasia of bronchial epithelium in smokers).

Barrett Esophagus

Glandular (intestinal) metaplasia of the distal esophageal squamous mucosa secondary to chronic acid reflux.

Dysplasia

Disordered epithelial growth and maturation regarded as a precancerous lesion; classic example is cervical intraepithelial neoplasia detected on PAP smear.

Cervical Intraepithelial Neoplasia (CIN)

Graded spectrum (I–III) of cervical dysplasia associated with high-risk HPV infection; may progress to invasive carcinoma.

Anaplasia

Undifferentiated, uncontrolled cellular growth—the histologic hallmark of malignancy; synonymous with carcinoma, cancer, or neoplasm.

Cellular Pleomorphism

Variation in size and shape of cells and nuclei, a microscopic hallmark of anaplasia.

Hyperchromatic Nucleus

Dark-staining, irregular nucleus characteristic of malignant (anaplastic) cells.

High Nuclear-to-Cytoplasmic (N/C) Ratio

Feature of anaplasia where the nucleus approximates the size of the entire cell (≈1:1) instead of normal 1:4–1:6.

Necrosis

Irreversible cell death within a living organism accompanied by inflammation.

Autolysis

Self-digestion of cells after organismal death, occurring without inflammatory response.

Coagulative Necrosis

Most common necrosis where architecture is preserved but proteins denature; typical of ischemic injury to solid organs (e.g., myocardial infarct).

Liquefactive Necrosis

Complete enzymatic digestion of dead cells into a liquid mass; common in brain infarcts and bacterial abscesses.

Caseous Necrosis

Cheesy, yellowish coagulative necrosis characteristic of tuberculosis or some fungal infections, forming granulomas (Ghon complex in lung).

Fat Necrosis

Destruction of adipose tissue by lipolytic enzymes, typically around traumatised pancreas, producing chalky calcium soaps.

Gangrene

Necrosis plus superimposed bacterial infection (wet) or desiccation (dry), often in ischemic limbs or intestines.

Wet Gangrene

Coagulative necrosis modified by bacterial liquefaction and inflammation, as in infected decubitus ulcers or diabetic foot.

Dry Gangrene

Mummified black tissue formed when necrotic parts dry out, classically in frostbite or peripheral arterial disease.

Dystrophic Calcification

Deposition of calcium salts in dead or damaged tissues despite normal serum calcium; seen in atherosclerotic plaques and aortic stenosis.

Metastatic Calcification

Calcium deposition in normal tissues due to hypercalcemia (e.g., hyperparathyroidism, vitamin D toxicity, chronic renal failure).

Atherosclerosis

Intimal lipid and calcium plaque buildup within arterial walls that can undergo dystrophic calcification, narrowing vessels.

Calcified Aortic Stenosis

Valve obstruction produced by dystrophic calcification of aortic cusps, impeding blood outflow from the heart.

Pap Smear

Cytologic screening test used to detect cervical dysplasia and early cancerous changes.

Concentric Left Ventricular Hypertrophy

Uniform thickening of LV wall in response to pressure overload such as systemic hypertension.

Bronchial Squamous Metaplasia

Replacement of normal ciliated columnar epithelium with stratified squamous epithelium in smokers’ airways.

Benign Prostatic Hyperplasia (BPH)

Non-malignant enlargement of prostate showing both hyperplasia and hypertrophy of glands and stroma.

Ghon Complex

Primary tuberculous lesion with caseous necrosis that may calcify and contain infection.

Calcium Oxalate Stone

Crystalline concretion forming in kidney, gallbladder, or bladder due to metastatic calcification processes.