Cell Adaptation & Necrosis

Vocabulary flashcards covering definitions and key features of cellular adaptation, necrosis, calcification, and related pathological terms.

Cellular Adaptation

Reversible structural or functional changes that cells undergo in response to prolonged or exaggerated stimuli.

Ways Cells Adapt to Change

atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia, anaplasia

Atrophy

Decrease in the size of a tissue, organ, or the entire body

Ex: muscles and bones in the elderly, Alzheimer’s

Physiologic Atrophy

Normal decrease in tissue size

Ex: thymus involution (shrinking in size)

Pathologic Atrophy

Shrinkage caused by disease or adverse conditions

Ex: post-menopausal atrophy of uterus, ovaries, and breasts, atherosclerotic kidneys, testicular atrophy, Alzheimer’s

Hypertrophy

Increase in tissue or organ size resulting from enlargement of individual cells without an increase in cell number.

Physiologic Hypertrophy

Enlargement of skeletal muscles

Ex: body builders due to weights, uterine muscle growth during pregnancy.

Pathologic Hypertrophy

Cell enlargement secondary to disease

Ex: concentric left-ventricular (systemic) hypertrophy from hypertension, hypertensive heart

Hyperplasia

Increase in the number of cells, leading to tissue or organ enlargement (e.g., endometrial hyperplasia, colon or stomach polyps).

Hypertrophy With Hyperplasia

pregnancy (uterine smooth muscle hypertrophy with hyperplasia)

benign prostatic hyperplasia increases size and number of glands in prostate

Metaplasia

Pathologic and reversible adaptable changing of one epithelial cell type to another

Ex: squamous metaplasia in smokers, gastric or glandular metaplasia of GE Junction in Barrett’s Esophagus

Pathway to Anaplasia

1. Metaplasia

2. Dysplasia (pre-cancer)

3. Anaplasia (cancer)

Dysplasia

Pathological cellular growth resulting from chronic irritation or infection, regarded as a precancerous change

Ex: is cervical dysplasia (CIN) detected on Pap smear.

Hypertension & Hypertrophy

increased size of heart due to excessive left ventricular pressure from hypertension

Anaplasia

Undifferentiated, uncontrolled malignant cell growth; synonymous with malignancy, carcinoma, cancer, or neoplasm.

Worst kind of cell adaptation

Cellular Pleomorphism

Hallmark of anaplasia

Variation in size and shape of cells and nuclei

Hyperchromatic Irregular Nuclei

Hallmark of anaplasia

Dark-staining, oddly shaped nuclei

High Nuclear/Cytoplasmic (N/C) Ratio

Hallmark of anaplasia

Approximately 1:1 proportion of nucleus to cytoplasm (normal ≈1:4–1:6).

Prominent Nucleoli

Hallmark of anaplasia

Large, conspicuous nucleoli within malignant nuclei

Abnormal Mitotic Figures

Hallmark of anaplasia

Numerous, atypical mitoses indicating rapid, uncontrolled cell division

Necrosis

Death of cells or tissues within a living organism, usually accompanied by inflammation.

Autolysis

Self-digestion of cells that occurs after death; lacks inflammatory response, unlike necrosis.

Coagulative Necrosis

Most common type of necrosis; protein denaturation preserves cell outlines; often caused by anorexia

Ex: myocardial infarct, renal or splenic infarct

Liquefactive Necrosis

Enzymatic digestion converts tissue into a soft, liquid mass

Ex: brain infarcts or abscesses.

Caseous Necrosis

Cheesy, yellowish form of coagulative necrosis

Ex: tuberculosis granulomas (Ghon complex) and some fungal infections.

Tuberculosis Characteristics

development of lung granulomas containing caseous necrosis

Fat Necrosis

Liquefactive destruction of fat by lipases, producing chalky white calcium soaps,

near fat or the pancreas

Wet Gangrene

Bacterial infection of coagulative necrosis, producing liquefaction, malodor, and sepsis

Ex: decubitus ulcers

Dry Gangrene

Mummification of ischemic tissue that dries, shrinks, and turns black, commonly seen in frostbite or severe peripheral arterial disease.

Dystrophic Calcification

Macroscopic deposition of calcium salts in dead or dying tissues (necrotic tissue)

Ex: atherosclerotic plaques, calcified heart valves, breast cancers calcifications, infant periventricular area (from toxoplasmosis)

Metastatic Calcification

The deposition of calcium salts in normal tissues because of deranged calcium metabolism (hypercalcemia)

Disorders Associated: hyperparathyroidism, Vitamin D toxicity, chronic renal failure