Ch. 4 - Cell Injury, Aging, and Death

These flashcards cover key vocabulary terms related to cell injury, aging, and death as discussed in the lecture.

Cell Injury

Damage to cells caused by various environmental factors or internal dysfunction.

Necrosis

Pathological cell death due to external injury characterized by cell rupture and inflammation.

Apoptosis

Programmed cell death, a physiological process that eliminates unnecessary or damaged cells without causing inflammation.

Reversible Injury

Cell injury that allows the cell to recover and return to its normal function.

Irreversible Injury

Damage to cells that leads to cell death and cannot be reversed.

Hydropic Swelling

A primary manifestation of reversible cell injury characterized by excessive water accumulation in cells.

Atrophy

Decrease in cell size and function due to various factors including decreased workload and inadequate nutrition.

Hypertrophy

Increase in cell size and organ size, often as a response to increased workload or hormonal stimulation.

Hyperplasia

Increase in the number of cells in a tissue or organ, often in response to physiological demand.

Metaplasia

Reversible change in which one adult cell type is replaced by another, usually in response to chronic irritation.

Dysplasia

Disordered growth of cells characterized by variations in size, shape, and arrangement; potential precursor to cancer.

Somatic Death

Death of the entire organism, characterized by the cessation of all biological functions.

Hypoxia

Low oxygen levels that impair ATP production; the most common cause of cell injury.

Ischemia

Reduced blood flow leading to oxygen and nutrient deprivation.

Free Radical Injury

Cell damage caused by reactive oxygen species (ROS) that attacks lipids, proteins, and DNA.

Oxidative Stress

An imbalance between ROS production and the cell’s ability to detoxify them.

Intracellular Accumulations

Build-up of abnormal amounts of substances such as lipids, proteins, pigments, or calcium within cells.

Fatty Change (Steatosis)

Accumulation of lipids within cells, commonly seen in livers cells.

Coagulative Necrosis

Preservation of tissue architecture; commonly due to ischemia.

Liquefactive Necrosis

Formation of liquid mass; typical in brain infarcts and abscesses.

Caseous Necrosis

Cheese-like appearance; associated with tuberculosis.

Fat Necrosis

Destruction of fat cells often due to pancreatitis or trauma.

Gangrenous Necrosis

Large area of necrosis due to ischemia.

Dry Gangrene

Coagulative necrosis with dry, shriveled tissue; mainly from arterial obstruction.

Wet Gangrene

Liquefactive necrosis with bacterial infection; tissue appears wet and swollen.

Gas Gangrene

Caused by Clostridium infection producing gas bubbles in tissue.

Intrinsic Apoptosis Pathway

Triggered by internal signals such as DNA damage or mitochondrial dysfunction.

Extrinsic Apoptosis Pathway

Triggered by external signals such as death receptors on the cell surface.

Cellular Aging

Progressive decline in cell function due to accumulated damage and decreased replication capacity.

Telomere Shortening

Reduction in telomere length with each cell division, limiting replicative lifespan.

Autophagy

Cellular “self-eating” process that removes damaged components to maintain survival.

Etiology of Cellular Injury

Cell injury may result from physical, chemical, infectious, immunologic, nutritional, or mechanical factors.

Reperfusion Injury

Cell injury that occurs after blood flow is restored, caused by reactive oxygen species and inflammation.

Chaperone Proteins

Proteins that assist with normal protein folding and prevent accumulation of misfolded proteins.

Ubiquitin-Proteasome System

A pathway that tags abnormal or misfolded proteins for degradation.

Indicators of Cell Death

Pain, inflammation, fever, elevated WBC count, increased serum enzymes, and loss of function.

Physiologic Hypertrophy

Normal increase in cell size due to hormonal or functional demand (e.g., uterus in pregnancy).

Pathologic Hypertrophy

Abnormal increase in cell size due to disease (e.g., hypertrophic heart in hypertension).

Postmortem Changes

Include rigor mortis, body fluid settling, and tissue breakdown from autolysis.