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Cell inj 1.pdf

  1. By Dr. Mayada Saad Farrag Lecturer of Pathlogy Faculty of Medicine
  2. Welcome
  3. Key Concepts * Normal cells have a fairly narrow range of function or steady state: Homeostasis. • Excess physiologic or pathologic stress may force the cell to a new steady state: Adaptation. * Too much stress exceeds the cell’s adaptive capacity: Injury.
  4. Adaptation Reversible Injury Irreversible injury Cell Death Normal cell Cellular Response to Stress
  5. Adaptations It is modification of cell morphology and function to achieve a new steady but altered state, preserving the viability of cells, which include 1- Hypertrophy 2 –Atrophy 3- Hyperplasia 4- Metaplasia
  6. Hypertrophy - Hypertrophy is an increase in the size of organ by + size of its individual cells, in response to a stimulus or injury. -RNA synthesis.
  7. Types  Physiological  Hormonal: pregnancy  Adaptive: athletes  Pathological  Hormonal: Gigantism  Adaptive: LVH  Compensatory: paired organs
  8. Hyperplasia -Is an increase in organ size by increase of number of its cells, in response to a stimulus or persistent cell injury. -DNA synthesis -Imp:  C/p: mass - bleeding  Reversible  Precancerous
  9. Types  Physiological  Hormonal: Lactation (breast)  Adaptive: puberty (thyroid)  Pathological  Hormonal: endometrial  Irritative: epithelium  Compensatory: hepatoctes
  10. Hyperplasia Normal adult breast Lactating breast Prostatic Hyperplasia
  11. Atrophy - Shrinkage in the size of organ by decrease size &/or number of its cells - Atrophied cells are smaller than normal but they are still viable.
  12. Atrophy Physiologic  General:senility  Local:Tissues / structures present in embryo or in childhood. Pathologic  General: starvatin –toxic-hormonal  Local Disuse Neurogenic Ischaemic Hormonal Thermal Immune pressure
  13. Atrophy, Myocytes are thinner and less colorful than normal, due to severe iron deficiency anemia.
  14. Morphology N/E  General Skin: wrinkled Fat: exhausted Muscles: wasted Lung: atrophic emphysema Bone: osteoporosis Heart: brown atrophy  Local: decrease size & weight. M/E  Cytoplasm: reduced  Nucleus: normal  Intercellular spaces: fibrous or fibrofatty tissue.
  15. Metaplasia -A reversible change in which one mature/adult cell type (epithelial or mesenchymal) is replaced by another mature cell type of the same category. - A/E: Chronic irritation- avitminosis A- genetic - Types: Epithelial, C.T, Mesothelial
  16. Epithelial metaplasia  Causes: It is an adaptive mechanism by which the cells less sensitive to stress are replaced by other cell type more capable to withstand the adverse enviroment.  Types: - Squamous metaplasia. - Glandular metaplasia. - Mesothelial metaplasia.  It may be precancerous especially epithelial metaplasia although it is reversible
  17. Barrett’s oesophagus