[C] 1.16 Degenerative changes of cells and tissues Flashcards Preview

Pathology A - General Pathology > [C] 1.16 Degenerative changes of cells and tissues > Flashcards

Flashcards in [C] 1.16 Degenerative changes of cells and tissues Deck (21)
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1
Q

Cell injury was defined by…

A

Rudolf Virchow

2
Q

Mechanisms of cell injury: General considerations

A
  • Cellular response depends on:
    • Type, duration, severity of harm
  • Consequences depend on:
    • Type, condition, adaptability of the cell
3
Q

Cellular injury results from functional, and biochemical abnormalities in one or more of which essential cell components?

A
  • Oxidative phosphorylation (ATP)
  • Membrane integrity
  • Protein synthesis
  • Cytoskeleton
  • DNA integrity
4
Q

ATP synthesis as a mechanism of cell injury: Steps

A
  1. ATP decrease
  2. Rise in IC Ca2+
  3. Mitochondrial damage
  4. ROS levels rising
  5. Membrane permeability defects
5
Q

ATP decrease as a mechanism of cell injury

A
  1. ↓ Na+/K+ ATPase pump activity
  2. IC [Na+] rise → Water influx → Cell swelling

or

  1. Anaerobic glycolysis: Glycogen depletes
  2. ↑ Lactic acid → ↓ pH
  3. ↓ Enzyme activity

or

  1. ↓ Ca2+,Mg2+ ATPase pump activity
6
Q

Rise in IC Ca2+ as a mechanism of cell injury

A

Enzyme activation:

  • ATPases:
    • Phospholipases
    • Proteases
    • Proteases
    • Endonucleases
    • Mitochondrion degeneration
7
Q

Mitochondrial damage

A
  1. ↑ Ca2+, phospholipases, ROS
  2. Cytochrome C leakage
  3. Apoptosis
8
Q

ROS levels rising (free radicals)

A
  1. Lipidperoxidation of the membranes
  2. Oxidative damage of proteins
  3. DNS damage
  • Antioxidant systems:
    • Glutathione peroxidase, superoxide dismutase, vitamin E, C
9
Q

Membrane permeability defects

A
  1. Mitochondrial damage
  2. ER-damage → Damaged protein synthesis
  3. Cytoskeletal abnormalities
  4. Leakage of lysosomal enzymes
10
Q

Title the figure

A

The effect of injury on cell injury

11
Q

Reperfusion injury

A

Restoration of blood flow after ischaemia → Severe cell damage

12
Q

Give the effects of reperfusion injury

A
  • Large oxygen influs, ROS
  • Mitochondrial damage
  • Compromised antioxidant system
  • Inflammation → Adhesion molecules expressed
    • These recruit neutrophils from restored blood flow
  • Complement pathway
13
Q

Degenerative cell and tissue damage cause

A

Altered function

14
Q

Altered cell function as a cause of degenerative cell and tissue damage

A

Not always visible

  • Detectable changes are needed
    • Deposition of certain materials
    • Enzymatic changes
    • Decreased function, metabolism
  • Most severe outcome: Cell death
15
Q

Degenerative/regressive changes of cells

A
  • Degeneration → Regressive changes
  • Metabolic disorders
    • Water metabolism
    • Fat
    • Protein
    • Mineral salts
    • Accumulation/deposition of different materials
16
Q

Forms of degeneration

A
  • Acquired - Congenital
  • Results from enzyme defects
    • Incomplete decomposition of a material
    • Same end product
    • Different end product
    • Accumulation of intermediate metabolites
      • Thesaurismosis
17
Q

Intracellular changes

A
  • Damage of the cell organelles
    • ER, mitochondrion
  • Deposition or accumulation
  • Depletion
  • Nuclear damage
  • Cell death
18
Q

Damage of the cell organelles

A
  • Membrane lined organelles
  • The membrane tears up
    • Enzyme leakage
    • SER dilation
    • Circumscribed necrosis
19
Q

Nuclear changes

A
  • Nuclear membrane hyperchromatosis
  • Karyopycnosis
  • Karyorhexis
  • Karyolysis
20
Q

Regressive tissue changes

A
  • Cell degeneration
  • Degeneration of the ECM
    • Deposition
    • Accumulation
    • Depletion of different molecules
    • Damage of the terminal blood system
21
Q

Regressive changes in the organs

A
  • Cell degeneration +
  • ECM degeneration +
  • Fibrovascular system degeneration
    • Not only the blood circulation
  • Atrophy

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