In reversible Hypoxia, explain; 1. Cellular swelling 2. Decreased pH 3. Decreased protein synthesis

Reduced Oxidative phosphorylation-> Reduced ATP 1. Reduced ATP= Reduced Na Pump activity-> Influx of Ca, H2O, Na-> Swelling of cell 2. Reduced ATP= Increased anaerobic glycolysis-> Increased [lactic acid]—> Reduced pH 3. Reduced ATP= Ribosomes detachment-> Reduced protein synthesis

In irreversible hypoxia, 1. How does cytosolic Ca increase 2. Which 4 enzymes are stimulated and what is their effect

1. Enters from Extracellular space, mitochondria, ER 2. ATPase- Reduced ATP Phospholipase- Less Phospholipids Protease- Disrupted membrane Endonuclease- Damages chromatin

When looking through an electron microscope, Compare Reversible and Irreversible injury in terms of; 1. Cell membrane 2. ER 3. Ribosomes 4. Mitochondria 5. Nucleus

1. Reversible-Blebs. Irreversible- Myelin figures, defects 2. Reversible- ER Swells. Irreversible- ER Lysis 3. Reversible- Dispersion. Irreversible- Rupture 4. Reversible- Swelling, small densities. Irreversible- Swelling, Large densities 5. Reversible- Chromatin clumping. Irreversible- Shrinking, Fragmenting, Dissolving

In caseous necrosis, 1. What is seen under a microscope 2. What it is associated with 3. Appearance by the eye

1. Amorphous debris 2. Infections, especially TB 3. Cheesy

In fat necrosis; 1. Describe the appearance 2. When and how does it occur

1. Melted candle-like 2. Often, acute pancreatitis causes pancreatic lipase release

Cell Injury And Death Flashcards by Ronit Hardasani

What 4 things does the degree of injury depend on

Type of injury
Severity of injury
Duration of injury
Type of tissue

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What 7 things can cause cell injury

Hypoxia
Chemical agents 
Physical agents 
Micro-organisms
Immune mechanisms 
Dietary deficiencies/ excesses
Genetic abnormalities

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Name 5 physical agents that can cause cell injury

Direct trauma 
Extreme temperatures 
Pressure changes 
Electric currents
Radiation

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Compare Hypoxia and Ischaemia

Hypoxia- Low O2

Ischaemia- Low O2 AND other substances

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Compare the 4 types of Hypoxia

Give one example of each

Hypoaxemic Hypoxia: Low O2 in arteries
High altitude

Anaemic Hypoxia: Decreased ability of Hb to carry O2
Anaemia or CO poisoning

Ischaemic Hypoxia: Interruption to blood supply
Vessel blockage

Histiocytic Hypoxia: Unable to use O2, due to disabled Oxidative phosphorylation enzymes
Cyanide poisoning

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Explain 2 ways in which immune system can damage the body

Hypersensitivity reactions: Overly vigorous immune reaction damages tissue
Autoimmune reactions: Immune system fails to distinguish self from non-self

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Which 4 cell components are most susceptible to injury

Membranes (Plasma + Organellar)
Nucleus (DNA)
Proteins (Structural)
Mitochondria (Oxidative phosphorylation)

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In reversible Hypoxia, explain;

Cellular swelling
Decreased pH
Decreased protein synthesis

Reduced Oxidative phosphorylation-> Reduced ATP

Reduced ATP= Reduced Na Pump activity-> Influx of Ca, H2O, Na-> Swelling of cell
Reduced ATP= Increased anaerobic glycolysis-> Increased [lactic acid]—> Reduced pH
Reduced ATP= Ribosomes detachment-> Reduced protein synthesis

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In irreversible hypoxia,

How does cytosolic Ca increase
Which 4 enzymes are stimulated and what is their effect

Enters from Extracellular space, mitochondria, ER
ATPase- Reduced ATP

Phospholipase- Less Phospholipids

Protease- Disrupted membrane

Endonuclease- Damages chromatin

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Give 5 ways free radicals can be made in the body

Normal metabolic reactions
Inflammation
Radiation
Reaction with unbound metals
Drugs/ chemicals

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How do heat shock proteins protect the cell

Give on example of one of these

When damaged, these proteins ‘mend’ mis-folded proteins and maintain cell viability

Ubiquitin

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What is Ischaemia-Reperfusion injury

Explain 3 causes

If blood flow is returned to a damaged, but not necrotic, damage can be worse than if blood flow wasn’t retuned

Possible causes;

Increased production of free radicals with reoxygenation
Increased neutrophil number-> More inflammation and tissue injury
Delivery of complement proteins

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In injured/ dying cells appear under a light microscope in hypoxia, explain the visible changes

Cytoplasm swells, becomes more pink and watery

2. 
Nucleus shrinks ( Pyknosis)
Nucleus fragments (Karyorrhexis)
Nucleus dissolves (Karyolysis)

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In hypoxia, what are the 3 cellular changes in order

Cytoplasmic changes
Nuclear changes
Abnormal cellular accumulations

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When looking through an electron microscope, Compare Reversible and Irreversible injury in terms of;

Cell membrane
ER
Ribosomes
Mitochondria
Nucleus

Reversible-Blebs. Irreversible- Myelin figures, defects
Reversible- ER Swells. Irreversible- ER Lysis
Reversible- Dispersion. Irreversible- Rupture
Reversible- Swelling, small densities. Irreversible- Swelling, Large densities
Reversible- Chromatin clumping. Irreversible- Shrinking, Fragmenting, Dissolving

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Define Oncosis
Define Necrosis
When is necrosis seen

Oncosis: Cell death with swelling, changes prior to death

Necrosis: Morphologic changes in a living organism, after a cell has been dead some tome

seen after 12 to 24 hours

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Name the 4 types of Necrosis

Where do the main 2 types occur, Give 2 examples

Coagulative Necrosis: In solid organs (Heart, Liver)

Liquefactive/ colliquitive Necrosis: In loose tissues (Brain, lungs)

Caseous Necrosis

Fat Necrosis

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Define Liquefaction

Compare Coagulative and Liquefactive

Liquefaction= enzymatic digestion

Coagulative: Protein denaturation, Ghost outline of cells remains
Liquefactive: Tissue digestion by enzymes

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In caseous necrosis,

What is seen under a microscope
What it is associated with
Appearance by the eye

Amorphous debris
Infections, especially TB
Cheesy

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In fat necrosis;

Describe the appearance
When and how does it occur

Melted candle-like

2. Often, acute pancreatitis causes pancreatic lipase release

Define Apoptosis
Does it use ATP
What are the 2 types

Cell death with shrinkage, induced by a regulated intracellular program

Yes
Pathological and Physiological

When does Physiological Apoptosis occur

Give 3 examples

To maintain a steady-state
Hormone controlled involution
Embryogenesis

when does pathological Apoptosis occur

Graft VS Host disease
Damaged cells (Especially DNA)
Virus-infected OR Neoplastic cells

Name the 4 visible stages in apoptosis

Normal cell
Shrinkage, chromatin Condensation
Fragmentation/ budding
Apoptic bodies

Name the 3 PHASES in apoptosis

Initiation Execution Degradation and Phagocytosis

Compare the 2 mechanisms for apoptosis and which phases they trigger What do they both result in

Intrinsic- Initiating signal from within cell Extrinisc- Extracellular initiating signals Initiation and execution Activation of caspases (enzymes than mediate apoptosis)

# Define Gangrene Compare Dry and Wet gangrene What type of necrosis are these What is Gas gangrene

Necrosis visible to the naked eye Dry: Necrosis modified by exposure to air- Coagulative Necrosis Wet: Necrosis modified by infection- Liquefactive Necrosis Gas: Wet gangrene where the infection is with anaerobic bacteria that produce gas

Define an Infarction | Define Infarct

Infarction: Necrosis caused by reduction in arterial blood flow Infarct: An area of necrotic tissue which is the result of loss of an arterial blood supply

What are the 2 most common causes of infarction

Thrombosis | Embolism

What is a white Infarct called Where does it happen What shape are they

Anaemic Infarct In solid organs, at end artery Wedge shaped

What is a red Infarct called | Where does one occur

Haemorrhagic Infarct | Loose tissue

What is the range of consequences of an infarction | What 4 factors does this depend on?

None to death Alternative blood supply Ischaemia speed Tissue involved Oxygen content of blood

What 3 molecules are released by injured cells

Potassium Myoglobin Enzymes

What 5 types of molecules can accumulate in injured cells

1. Water and electrolytes 2. Lipids 3. Carbs 4. Proteins 5. Pigments

When fluid accumulates in cells, 1. What the type of swelling 2. When does it occur 3. What enters cell

1. Hydropic swelling 2. When Energy supplies cut off 3. Na and H2O flood into cell

What is triglyceride accumulation called, where is it most often What are 4 causes of lipid accumulation in cells If mild, what are the symptoms

Hepatic Steatosis Alcohol (Reversible) Diabetes Mellitus Obesity Toxins None

In what 2 conditions do proteins accumulate in a cell | Explain these

- Alcoholic liver disease, Mallory’s hyaline accumulates | - Alpha1 anitrypsin deficiency. Incorrectly folded “” protein (A protease inhibitor)

Name 2 exogenous pigments that accumulate in cells How do phagocytes play a role

Carbon/ coal dust/ soot- Phagocytosed by alveolar macrophages Tattoos- Phagocytosed by macrophages in dermis and remains

Inhalation of carbon leads to which 2 conditions

Anthracosis Pneumoconiosis

Name 2 endogenous pigments that accumulate in cells

Haemosiderin (Iron storage molecule) Bilirubin (breakdown product of heme)

When does Haemosiderin accumulate in a cell Give one way this can occur What is Haemosiderosis

When there is systemic or local excess of Iron Bruising Systemic Iron overload, so Fe deposited in organs

What is hereditary Haemochromatosis Name 2 organs other than endocrine organs where Fe is deposited Name 3 symptoms

A genetic disorder caused increased Fe absorption in intestine Skin, Heart Liver damage, Heart dysfunction, endocrine failures

Compare Dystrophic/ Metastatic calcification | Which is more common

Dystrophic: Abnormal localised deposition of Ca salts in tissues Metastatic: Abormal systemic deposition of Ca salts in tissues More common- Dystrophic

Where does Dystrophic calcification occur, give 3 examples?

Area of dying tissue, aging/ damaged valves, TB Lymph nodes

Why does Dystrophic calcification occur

No abnormality in Ca metabolism Local change favours nucleation of hydroxyapatite crystals

Why does Metastatic calcification occur | Compare normal symptoms and lethality

Due to hypercalcaemia, secondary to disturbances In Ca metabolism usually no symptoms, can be lethal

What are 2 causes of hypercalcaemia

- Increased secretion of PTH causing Bon resporption | - Destruction of bone tissue

Why can cells not keep diving forever

Telomere is shortened each division | When telomere is at critical length, cell can’t divide anymore

How do germ cells have the capability to keep dividing Name 2 other cell types which can do this

Contain telomerase, which maintains original length of telomeres Stem cells, Cancer cells