Pathophysiology Fundamentals (I) PDF

## Pathophysiology Fundamentals (I) ### Understanding Cells - Cells are the smallest living components and basic building blocks of organisms, forming tissues and organs that integrate into body systems. - Cells encounter challenges like stressors and diseases throughout their lifespan, affectin...

## Pathophysiology Fundamentals (I) ### Understanding Cells - Cells are the smallest living components and basic building blocks of organisms, forming tissues and organs that integrate into body systems. - Cells encounter challenges like stressors and diseases throughout their lifespan, affecting their normal function. - Cells respond to stress by using reserves to continue functioning or adapting through changes such as: - Atrophy (size reduction) - Hypertrophy (size increase) - Hyperplasia (cell number increase) - Metaplasia (cell type replacement) - Dysplasia (abnormal growth) ### Cell Injury - Cell injury, reflecting wellness or disease, can result from biochemical lesions and be influenced by toxins, infections, or physical and deficit injuries. - **Toxic injury:** Caused by internal (endogenous) factors like metabolic errors or external (exogenous) factors like drugs and alcohol. - **Infectious injury:** Caused by agents like viruses and bacteria, often disrupting cell synthesis - **Physical injury:** Results from thermal (e.g., radiation) or mechanical (e.g., trauma) disruptions. - **Deficit injury:** Occurs due to deficits in water, oxygen, nutrients, temperature regulation, or waste disposal, leading to cell disruption or death. ### Cell Degeneration, Aging and Death - Nonlethal damage generally affecting the cytoplasm, caused by factors like swelling, fatty infiltrates, and atrophy. - Cells lose structure and function with aging, influenced by the extent of injuries and wear and tear, affecting all body systems. - Caused by intrinsic factors limiting lifespan or extrinsic factors leading to damage and aging. - Factors affecting cell aging include intrinsic factors like metabolic and nutritional factors, and extrinsic factors like physical agents, chemicals, and infectious agents. ### Summing Up - Cells are the smallest living structures and the basic units of life. - Organisms vary from single-celled to complex beings with millions of cells. - Cells form tissues, which then create organs and body systems. - Cell function can be altered by stressors and diseases. - Cells may adapt, use reserves, or fail under stress. - Atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia are common cell changes. - Cell injury can indicate and cause diseases - In response to injury, cells use reserves or adapt; if reserves run out, cells die (necrosis). - Cells can be injured by toxic, infectious, physical, or deficit-related factors. - Cell degeneration involves nonlethal damage in active organs and can be slowed with treatment. - Aging affects cells, reducing elasticity, muscle mass, and causing skin changes. - Both intrinsic and extrinsic factors impact cell lifespan and aging.