1. Altered Cellular and Tissue Biology
Chapter 3

2. Key to Understanding Disease “knowledge of structural and functional reactions of cells and tissues to injurious agents” (including genetic defects)

3. Cellular Adaptation
“cells adapt to their environment to escape and protect themselves from injury”
Common
Central part of many disease states

4. Altered Cellular & Tissue Biology can result from…
Adaption
Injury
Neoplasm
Aging
death

5. Physiologic verses Pathogenic
Cellular Adaptation
Physiologic verses Pathogenic
Atrophy
Hypertrophy
Hyperplasia
Metaplasia
Dysplasia (atypical hyperplasia)

6. Cellular Adaptation

7. Cellular Adaptation

8. Biochemical Mechanism
Cell Injury…”BIG PICTURE”
Biochemical Mechanism
ATP depletion
Oxygen & oxygen derived free radicals
Calcium alterations
Defects in membrane permeable

9. Common forms Cell Injury Hypoxic injury
Free radicals/reactive oxygen species injury
Chemical injury

11. Cellular Injury - Hypoxia

13. Cellular Injury:Reprofusion

16. Chemical Injury “biochemical interaction with toxic substance”
Direct toxicity – at cell membrane or organelles
Formation of reactive free radicals and lipid peroxidation

17. Chemical Injury

18. 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

19. Common Drugs of Abuse Opioid narcotics Sedative-hypnotics
Psychomotor stimulants
Phencycielidine-like drugs Table 3-5/6
Cannabinoids
Hallucinogens
Marijuana
Methamphetamine
Cocaine
Heroin

20. 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

21. Unintentional and Intentional Injuries
Sharp injuries
Incised wounds
Stab wound
Puncture wound
Chopping wound

22. Unintentional and Intentional Injuries

23. Unintentional and Intentional Injuries

24. Unintentional and Intentional Injuries
Gunshot wounds
Entrance
Exit
Asphyxial Injuries
Suffocation
Strangulation
Chemical – CO, cyanide, hydrogen sulfate
Drowning

25. Infectious Injury Pathogenicity of a microorganism
Invasion and destruction
Toxin production
Hypersensitivity reaction → damage

26. complement and protease Cell membrane injury/function
Immunologic & Inflammatory Injury
Phagocytic cells, antibodies, lymphokines,
complement and protease ↓
Cell membrane injury/function
↑ water ↑ Na+ ↓K+

27. 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

28. Hydropic Degeneration

29. Calcium Infiltration

30. Cellular Death Necrosis
Sum of the cellular changes after local cell death and the process of cellular autodigestion (autolysis)

31. Cellular Death : Nucleus
Processes
Karyolysis – nuclear dissolution, chromatinlysis
Pyknosis – clumping of the nucleus
Karyorrhexis – fragmentation of nucleus

32. Cellular Death

33. 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”

34. Coagulative Necrosis (cont’d)

35. Liquefactive Necrosis:Brain

36. Caseous Necrosis (cont’d)

37. Fat Necrosis: Pancreas

38. Gangrenous Necrosis

39. 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

42. Theories of Aging Accumulation of injurious events
Genetically controlled program

45. 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° - ↓ °
Postmortem autolysis – release of enzymes and lytic dissolution (microscopic level)