Pathology

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"Great people are great because they solve
countless seemingly unsolvable problems you can
too.. if you choose to." Mark Victor Hansen
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Cellular Injury Ageing

• Dr. Venkatesh M. Shashidhar
• Senior Lecturer in Pathology
• Fiji School of Medicine

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Disease

• Dis Ease Disease.
• Discomfort due to Structural or functional
  abnormality
• Disease is caused by an agent.
• Causes (etiology) can be
• External / Environmental. E.g.. Heat, Bacteria.
• Internal E.g. stress, genes, ageing.

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Cellular Injury Adaptation

• Normal cell is in a steady state Homeostasis
• Change in Homeostasis due to stimuli - Injury
• Injury - Reversible / Irreversible
• Adaptation / cell death

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Response to Injury

• Adaptations (reversible)
• Hydropic degeneration
• Hypertrophy
• Hyperplasia
• Atrophy
• Accumulations - hyaline, fat, etc.
• Necrosis (irreversible) cell death.

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Terminology

• Necrosis Morphologic changes seen in dead cells
  within living tissue.
• Autolysis Dissolution of dead cells by the cells
  own digestive enzymes. (not seen)
• Apoptosis Programmed cell death. Physiological,
  for cell regulation.

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Types of Necrosis

• Coagulative Eg. Infarction
• Liquifactive - Brain, abscess
• Caseous - Bacterial / Tuberculosis
• Gangrene - With infection

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Sequels of Necrosis

• Cell Death
• Necrosis
• Autolysis
• Phagocytosis
• Organization fibrous repair.

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Hydropic change in ischemic - kidney
Microvilli
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Cerebral atrophy - Alzheimers
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Heart hypertrophy in hypertension
Left Ventricle
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Muscle ischemic atrophy
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Extensive Caseous necrosisTuberculosis
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Caseous necrosis - Tuberculosis
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Gangrene - Amputated Diabetic foot
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Gangrene Intestine - Thrombosis.
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Stroke- Liquifactive necrosis
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Liver abscess Liquifactive necrosis
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Renal Infarction - Coagulative
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Splenic Infarction - Coagulative necrosis
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Infarction - Adrenal gland
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Ageing
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Ageing

• Progressive time related loss of structural and
  functional capacity of cells leading to death
• Senescence, Senility, Senile changes.
• Ageing of a person is intimately related to
  cellular ageing.

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Factors affecting Ageing

• Genetic Clock genes, (fibroblasts)
• Diet malnutrition, obesity etc.
• Social conditions -
• Diseases Atherosclerosis, diabetes etc.
• Werners syndrome.

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Cellular mechanisms of ageing

• Cross linking proteins DNA.
• Accumulation of toxic by-products.
• Ageing genes.
• Loss of repair mechanism.
• Free radicle injury
• Telomerase shortening.

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Telomerase in ageing
Germ Cells Somatic Cells
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Ageing changes

• Gradual atrophy of tissues and organs.
• Dementia
• Loss of skin elasticity
• Greying and Loss of hair
• BV damage atherosclerosis/bruising.
• Loss of Lens elasticity ? opacity ? vision
• Lipofuscin pigment deposition Brown atrophy in
  vital organs.

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Pathology of elderly
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Factors affecting ageing

• Stress
• Infections
• Diseases
• Malnutrition
• Accidents

• Diminished stress response.
• Diminished immune response.
• Good health.

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Conclusions

• Cellular Injury - Various causes
• Reversible Injury ? Adaptations
• Hypertrophy, Hyperplasia, Atrophy
• Accumulations - Hydropic, hyaline, fat..
• Irreversible Injury - Necrosis
• Coagulative, Liquifactive, Caseous
• Ageing - Causes, Changes, Factors

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"No matter how dark things seem to be or actually
are, raise your sights and see the possibilities
always see them, for they're always there.
Norman Vincent Peale