Transcript Chapter 3
ALTERED CELLULAR AND TISSUE BIOLOGY Chapter 3 Key to Understanding Disease “knowledge of structural and functional reactions of cells and tissues to injurious agents” (including genetic defects) Cellular Adaptation “cells adapt to their environment to escape and protect themselves from injury” Common Central part of many disease states Altered Cellular & Tissue Biology can result from… Adaption Injury Neoplasm Aging death Cellular Adaptation Physiologic verses Pathogenic Atrophy Hypertrophy Hyperplasia Metaplasia Dysplasia (atypical hyperplasia) Cellular Adaptation Cellular Adaptation Cell Injury…”BIG PICTURE” Biochemical Mechanism ATP depletion Oxygen & oxygen derived free radicals Calcium alterations Defects in membrane permeable Cell Injury Common forms Hypoxic injury Free radicals/reactive oxygen species injury Chemical injury Cellular Injury - Hypoxia Cellular Injury:Reprofusion Chemical Injury “biochemical interaction with toxic substance” 1) Direct toxicity – at cell membrane or organelles 2) Formation of reactive free radicals and lipid peroxidation Chemical Injury Chemical Injury • • • • • • • • Poisons – arsenic, cyanide Air pollutants, insecticides, herbicides Carbon monoxide – carboxyhemoglobin (300 x O2) Carbon tetrachloride – Figure 3-9 Lead – Ca++, Hgb, brain, kidney Mercury – dental, fish, vaccines Ethanol – “free radicals” – most organs Social/street drugs Common Drugs of Abuse Opioid narcotics Sedative-hypnotics Psychomotor stimulants Phencycielidine-like drugs Cannabinoids Hallucinogens Marijuana Methamphetamine Cocaine Heroin Table 3-5/6 Unintentional and Intentional Injuries Blunt force injuries “application of mechanical energy to the body resulting in tearing, shearing, or crushing of tissues” Contusion verses hematoma Abrasion Laceration fractures Unintentional and Intentional Injuries Sharp injuries Incised wounds Stab wound Puncture wound Chopping wound Unintentional and Intentional Injuries Unintentional and Intentional Injuries Unintentional and Intentional Injuries Gunshot wounds Entrance Exit Asphyxial Injuries Suffocation Strangulation Chemical Drowning – CO, cyanide, hydrogen sulfate Infectious Injury Pathogenicity of a microorganism Invasion and destruction Toxin production Hypersensitivity reaction → damage Immunologic & Inflammatory Injury Phagocytic cells, antibodies, lymphokines, complement and protease ↓ Cell membrane injury/function ↓ ↑ water ↑ Na+ ↓K+ Manifestations of Cellular Injury Cellular accumulation (infiltrations) Water – most common Lipids and carbohydrates – metabolic disorders Glycogen – metabolic (genetic) disorders Proteins – renal, B lymphocytes Pigments – melanin, hemoproteins Calcium Urates – gout Hydropic Degeneration Calcium Infiltration Cellular Death Necrosis Sum of the cellular changes after local cell death and the process of cellular autodigestion (autolysis) Cellular Death : Nucleus Processes Karyolysis – nuclear dissolution, chromatinlysis Pyknosis – clumping of the nucleus Karyorrhexis – fragmentation of nucleus Cellular Death Necrosis …” different types in different organs” Coagulative – hypoxia, kidney, heart, adrenal Liquefactive – bacterial infections, ischemia – “lipids” Caseous – tuberculosis – combination coagulative / liquefactive Fat – breast, pancreas – lipases Gangrenous – “severe hypoxic injury” Coagulative Necrosis (cont’d) Liquefactive Necrosis:Brain Caseous Necrosis (cont’d) Fat Necrosis: Pancreas Gangrenous Necrosis Aptosis – single cell death Programmed Cell Death – 10 billion/day – suicide genes Physiologic – cell deletion during tissue turnover and normal embryonic development, endocrine dependent tissue Pathologic – intracellular and exogenous events Example: Viral hepatitis, radiation, chemotherapy Theories of Aging Accumulation of injurious events Genetically controlled program Somatic Death Death of the entire person Postmortem changes Algor mortis - ↓ temperature 1 – 1.5°F/hr x 24° Livor mortis – blood settling – gravity Rigor mortis – muscle stiffening → 12° - ↓ 36 -72° Postmortem autolysis – release of enzymes and lytic dissolution (microscopic level)