Cell Injury Flashcards

1
Q

What is the main reason of cell death

A

Oxygen deprivation
Hypoxia
Ischemia

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2
Q

What is Hypoxia

A

Loss of blood supply from impeded blood flow or reduced venous drainage in a tissue

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3
Q

What is Ischemia

A

Compromises the availability of metabolic substrates including glucose, tends to injure tissues faster than hypoxia

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4
Q

Other causes of Cell injury

A

Physical agents: mechanical trauma, burns,cold
Chemical agents and drugs: glucose, salt, hypertonic concentration, poisons, environmental pollutants
Infectious agents
Immunologic reactions: endogenous self ag, autoimmune disease,reaction to foreign protein or drug.
Genetic rearrangements: genetic injury, chromosomal abnormality
Nutritional imbalance: anorexia nervosa, obesity, atherosclerosis.

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5
Q

The cellular response to injurious stimuli depends on

A

Type of injury
Duration
Severity

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6
Q

The consequences of cell injury depend on the

A

Type
State
Adaptability of the injured cell

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7
Q

Which essential cellular components with an abnormality results with cell injury

A

Aerobic respiration involving mito oxidative phosphorilation and production of ATP
Maintenance of the integrity of cell membranes
Protein synthesis
Preservation of the integrity of the genetic apparatus of the cell

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8
Q

Which structure is responsible for turning injury reversible to irreversible

A

Integrity of cell membranes

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9
Q

Effects of degradation in ATP to Na pump

A

Na pump activity decreases— Ca+, H20 and Na+ influx and K+ efflux increases— ER swelling, Cellular swelling, Loss of microvilli, BLEBS

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10
Q

Effects of ATP decrease to Anaerobic glycolysis

A

Anaerobic glycolysis increases— glycogen and pH decreases — clumping of nuclear chromatin

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11
Q

Most common types of cellular injury

A

Ischemic
Hypoxic

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12
Q

Reperfusion injury

A

When blood flow is restored to cells that have been previously ischemic, injury can be excerbated.

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13
Q

What is the first effect of Hypoxia

A

Loss of oxidative phosphorylation and ATP generation by mitochondria

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14
Q

When the changes in the cell caused by Hypoxia can reverse

A

When oxygenation is restored

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15
Q

What happens when ATP depletion continuous

A

Membrane dysfunction
Mitochondrial membrane damage

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16
Q

What causes the release of cytochrome c

A

ATP depletion

17
Q

What is the result effect of loss of the membrane integrity

A

Massive influx of Ca
Which will inhibit the cellular enzymes denaturation of proteins and cytologies alterations characteristic of coagulation necrosis.

18
Q

Effects of Free Radicals to cell to cause injury

A

Lipid peroxidation of membranes
Oxidative modification of proteins
Damage to DNA

19
Q

Which series of enzymes act as a free radical scavenging systems

A

Catalase
Superoxide dismutase
Glutathione peroxidase

20
Q

How does chemicals cause cellular injury

A

1- Directly by binding to critical molecular component
2- Indirectly by conversion to reactive toxic metabolites
Sometimes: CCL4, Acetaminophen

21
Q

Which mechanisms remove free radicals and minimize cellular injury

A

Antioxidants
Binding of the ions to storage and transport proteins

22
Q

What are the marks of the irreversible injury

A

Mitochondrial vacuolization
Extensive damage to cell membranes
Swelling of lysosomes
the appearance of large amorphous densities in mitochondria

23
Q

Injury of lysosomal membranes result with

A

Leakage of enzymes into the cytoplasm and by their activation to enzymatic digestion of cell and nuclear components

24
Q

What are the processes that cause the basic morphological changes of necrosis

A

Denaturation of proteins
Enzymatic digestion of organelles and other Cytosolic components

25
Pyknosis
Small dense nuclei
26
Karyolysis
Faint dissolved nucleus
27
Karyrrhexis
Nucleus broken up into many clumps
28
Dystrophin Cacification
Necrotic cells may attack calcium salts in the form of glandular basophilic deposits
29
What are the types of necrosis
Coagulation necrosis Liquefaction necrosis Caseous necrosis Fat necrosis Fibrinoid necrosis
30
What is Coagulation necrosis
Most common type Characterized by denaturation of cytoplasmic proteins with preservation of the framework of the coagulated cell Occurs in myocardium, kidney, liver…
31
What is Liquefaction necrosis
Occurs when autolysis and heterolysis prevail over protein denaturation Necrotic area is soft and filled with fluid Mostly seen in localized bacterial infections and in brain(?)
32
Caseous necrosis
Characteristics of TUBERCULOSIS lesions Appears grossly as soft friable material Microscopically as amorphous eosinophilia material with cell debris
33
Fat necrosis
Necrosis in adipose tissue Induced by the activation of lipases then complex with Ca to create Ca soaps
34
What is Fibrinoid Necrosis
Special form of necrosis seen in immune reactions involving BV Occurs when compexes of ag and ab are deposited in the walls of arteries Fibrin leakage