Week 2 Flashcards: Cellular Injury & Death (Vocabulary)

A vocabulary-style set of flashcards covering key terms related to cellular injury, adaptation, and death as presented in Week 2 notes.

Apoptosis

Programmed, regulated cell death that occurs without provoking inflammation; a controlled process often involved in development and aging.

Necrosis

Uncontrolled cell death due to severe injury (e.g., ischemia, toxins) with membrane disruption and inflammation.

Ischemia

Inadequate blood supply causing oxygen deprivation and accumulation of metabolic wastes.

Ischemia-reperfusion injury

Tissue damage that occurs when blood supply returns after ischemia, involving calcium overload, free radicals, and inflammation.

Coagulative necrosis

Most common type of necrosis in solid organs; proteins denature and tissue architecture is preserved, followed by proteolysis.

Liquefactive necrosis

Necrosis where cells are digested by enzymes, forming a liquid or viscous mass; common in brain and abscesses.

Fat necrosis

Necrosis of fatty tissue often related to pancreatic enzymes or trauma; fatty acids may combine with calcium.

Caseous necrosis

Cheese-like necrosis typical of tuberculosis; incomplete digestion of necrotic tissue.

Gangrene

Extensive tissue necrosis due to loss of blood supply; includes dry, wet, and gas types.

Dry gangrene

Coagulative necrosis of tissue with a dry, black, wrinkled appearance and a clear line of demarcation.

Wet gangrene

Liquefactive necrosis with infection; tissue becomes wet and can be life-threatening.

Gas gangrene

Infection of necrotic tissue by anaerobic bacteria (Clostridium) with gas bubble formation in tissue.

Hydropic swelling

First sign of reversible cellular injury; failure of Na+/K+ pumps causing Na and water influx and cellular edema.

Edema

Abnormal accumulation of fluid in tissues or interstitial spaces.

Intracellular accumulations

Excess substances within cells (lipids, glycogen, proteins, pigments) due to metabolic or enzymatic defects.

Lysosomal storage disease

Group of disorders with accumulation of undigested substrates due to lysosomal enzyme defects.

Mallory-Denk bodies

Abnormal aggregates of cytoskeletal proteins seen in alcoholic liver disease.

Glycogen storage disease

Disorders of glycogen metabolism causing accumulation in liver and other tissues.

Cholestasis

Impaired bile flow leading to accumulation of bile pigments in the liver.

Hepatomegaly

Generalized enlargement of the liver.

Splenomegaly

Generalized enlargement of the spleen.

Atrophy

Decrease in cell size; causes include disuse, denervation, ischemia, starvation, endocrine changes, and injury.

Hypertrophy

Increase in cell size; usually due to increased workload or functional demand.

Hyperplasia

Increase in the number of cells; caused by functional demand, hormonal stimulation, persistent injury, or chronic irritation.

Metaplasia

Replacement of one mature cell type with another better suited to the environment; reversible if stimulus is removed.

Dysplasia

Disordered growth with cells of varying size and shape; often considered pre-cancerous.

Reversible cellular injuries

Injuries from which cells can recover once the injurious stimulus is removed.

Irreversible cellular injuries

Injuries that lead to cell death (necrosis or apoptosis) with loss of cell membrane integrity.

ATP depletion

Loss of cellular energy causing pump failure and impaired cellular functions, contributing to injury.

Reactive oxygen species (ROS)

Reactive molecules produced in metabolism; at high levels cause oxidative damage and signaling in cell injury.

Ischemic cascade

Sequence from oxygen/nutrient deficit to membrane and organelle damage leading to necrosis.

Mitochondrion

ATP generator; powerhouse of the cell; central to energy metabolism and cell death signaling.

Nucleus

Largest cytoplasmic organelle containing genetic material (DNA).

Nucleolus

Nuclear substructure where ribosomal RNA synthesis occurs.

Ribosomes

Ribosomal RNA–protein complexes; sites of protein synthesis; bound on rough ER or free in cytoplasm.

Rough endoplasmic reticulum

ER studded with ribosomes; site of protein synthesis and folding.

Smooth endoplasmic reticulum

ER involved in lipid synthesis and detoxification processes.

Golgi apparatus

Modifies, sorts, and packages proteins and lipids for transport to their destinations.

Plasma membrane

Phospholipid bilayer that regulates transport, maintains membrane potential, and enables cell signaling.

Lysosome

Digestive organelle that breaks down waste materials and cellular debris; final products include amino acids, fatty acids, and sugars.

Glycogen

Storage form of glucose in liver and muscle.

Glycogenolysis

Breakdown of glycogen to glucose to raise blood glucose levels during energy demand.

ACTH

Adrenocorticotropic hormone; stimulates cortisol production from the adrenal cortex.

Cortisol

Glucocorticoid hormone that raises blood glucose and has catabolic effects on proteins and immune function.

Programmed Senescence Theory

Intrinsic genetic program of aging; telomere shortening due to reduced telomerase activity over time.

Somatic death

Death of the entire organism; cessation of breathing and heartbeat, postmortem changes such as rigor mortis and autolysis.