Chapter 4: Cell Injury, Aging, and Death

Vocabulary flashcards covering cell injury mechanisms, cellular adaptation, types of necrosis, apoptosis, somatic death, and physiological changes associated with biological aging.

Hydropic Swelling (Oncosis)

Cellular swelling caused by the accumulation of water due to failure of the sodium-potassium pump, representing the first manifestation of most forms of reversible cell injury.

Megaly

Organ enlargement resulting from severe cellular swelling.

Intracellular Accumulation

The storage of excessive amounts of normal substances, abnormal substances from faulty metabolism, or indigestible pigments and particles within cells.

Cellular Adaptation

A reversible response to persistent cellular stress caused by increased functional demand or sub-lethal injury.

Atrophy

A decrease in cell size caused by disuse, denervation, ischemia, nutrient starvation, or persistent injury in an effort to minimize energy consumption.

Hypertrophy

An increase in cell mass accompanied by augmented functional capacity in response to increased physiologic or pathophysiologic demands, driven by increased cellular protein content.

Hyperplasia

An increase in functional capacity related to an increase in cell number through mitotic division in response to increased demands, hormonal stimulation, or persistent injury.

Metaplasia

The replacement of one differentiated cell type with another cell type that is better suited to tolerate persistent injurious stimulation.

Dysplasia

Disorganized appearance of cells caused by abnormal variations in size, shape, and arrangement, representing preneoplastic lesions with potential to transform into cancer.

Necrosis

Irreversible cell death resulting from ischemia or toxic injury, characterized by plasma membrane rupture, spilling of cellular contents into extracellular fluid, and inflammation.

Apoptosis

Programmed cell death triggered by external or internal pathways, resulting in regulated, tidy cellular degradation without cell rupture or inflammation.

Coagulative Necrosis

The most common type of necrosis, initiated by ischemia, resulting in calcium influx, mitochondrial dysfunction, and solid, degraded protein tissue.

Liquefactive Necrosis

A type of necrosis involving rapid dissolution of dead cells by lysosomal enzymes, leading to the formation of an abscess or cyst.

Fat Necrosis

Death of adipose tissue caused by degradative enzymes hydrolyzing fats into glycerol and fatty acids, appearing as chalky white tissue.

Caseous Necrosis

A form of cell death characteristic of lung damage from tuberculosis, in which dead tissue resembles clumpy cheese.

Gangrene

Cellular death involving a large area of tissue resulting from the interruption of blood supply.

Dry Gangrene

A form of coagulative necrosis characterized by blackened, dry, wrinkled tissue separated by a line of demarcation from healthy tissue.

Wet Gangrene

A form of liquefactive necrosis typically found in internal organs that can be fatal.

Gas Gangrene

Tissue necrosis resulting from infection by anaerobic Clostridium bacteria, characterized by gas bubble formation in damaged muscle tissue.

Ischemia

Cellular stress caused by interruption of blood supply, combining oxygen deprivation with the accumulation of metabolic waste products.

Ischemia-Reperfusion Injury

Cellular damage resulting from restored blood flow and oxygen, caused by calcium overload, free radical formation, and subsequent inflammation.

Somatic Death

Death of the entire organism, characterized by body cooling, pale skin, blood pooling, rigor mortis, and post-mortem autolysis without inflammatory responses.

Rigor Mortis

Stiffening of body muscles that occurs within $6\,hours$ after somatic death.

Post-Mortem Autolysis

Deterioration of body tissues following somatic death, caused by the release of lytic enzymes after rigor mortis passes.

Programmed Senescence Theory

Theory stating that cellular aging is controlled by an intrinsic genetic program linked to progressive shortening of telomeres with each cell replication.

Free Radical Theory

Theory stating that biological aging results from cumulative and progressive cellular damage caused by reactive oxygen species.

Senescence

The biological aging process during which cell death exceeds cell replacement.

Menopause

The permanent cessation of menstruation occurring at an average age of $50\,years$ due to ovarian unresponsiveness to FSH and LH.

Dyspareunia

Painful sexual intercourse experienced in aging females due to thinning vaginal mucosa, loss of elasticity, and decreased glandular secretions.

Benign Prostatic Hyperplasia (BPH)

Common non-cancerous enlargement of the prostate gland in aging males due to cellular proliferation.

Arteriosclerosis

Pathological condition in aging characterized by loss of elasticity and thickening of arteriolar walls, leading to increased peripheral resistance and tissue ischemia.

Atherosclerosis

Vascular condition characterized by hyperlipidemia and accumulation of cholesterol in the walls of large arteries, leading to narrowed lumens and ischemia.

Osteoporosis

Metabolic bone condition in aging characterized by loss of calcium and bone mass, resulting in an increased incidence of fractures in the spine, pelvis, and limbs.

Osteoarthritis

Wear-and-tear joint disease characterized by progressive degeneration and thinning of articular cartilage in large weight-bearing joints.

Herniated Intervertebral Disk

Degeneration of fibrocartilage in intervertebral disks with age, leading to disk protrusion, spinal nerve compression, and severe back pain.

Nocturia

Frequent nighttime urination caused by age-related reductions in kidney function, bladder capacity, and sphincter tone.

Incontinence

Involuntary voiding of urine resulting from weakened urinary sphincters and bladder muscles in older adults.