Cell injury, degeneration and death Flashcards
Quick overview of causes of cell injury (similar to causes of disease).
- physical agents
- ______ _____
- _______
- ______ and ______
- ________ _____
- ______
- _____ _____
Quick overview of causes of cell injury (similar to causes of disease).
- physical agents
- chemical agents (+drugs)
- infections
- hypoxia and ischaemia
- immunological reactions
- nutrition
- genetic disorders
Cell injury can be _____ or ______.
______:
- changes due to environment stress
- return to normal once stimulus removed
_______:
- permanent
- cell death, usually necrosis, follow
Cell injury can be reversible or irreversible.
Reversible:
- changes due to environment stress
- return to normal once stimulus removed
Irreversible:
- permanent
- cell death, usually necrosis, follow
Cell injury pathogenesis (mechanisms) -
locations cells can be damaged:
- ______: disrupted aerobic respiration/ATP synthesis
- ___ _____: disrupted ion concentrations, esp increased Ca2+
- ______: includes _____, disrupted enzymes and structural proteins synthesis and architecture
- _____: disrupted DNA maintenance and DNA damage
Cell injury pathogenesis (mechanisms)
Damage to:
- mitochondria: disrupted aerobic respiration/ATP synthesis
- cell membrane: disrupted ion concentrations, esp increased Ca2+
- cytoplasm: includes ribosomes, so disrupted enzymes and structural proteins synthesis and architecture
- nucleus: disrupted DNA maintenance and DNA damage
Cell injury pathogenesis (mechanisms) - oxidative stress:
- oxidative stress caused by ______ _____ _____ (___ ____)
- normally in small amounts as byproducts of ______
- formed pathologically by _____, ___ _____, _____ etc
- lack of _______ makes damage more severe
Cell injury pathogenesis (mechanisms) - oxidative stress:
- oxidative stress caused by reactive oxygen species (free radicals)
- normally in small amounts as byproducts of respiration
- formed pathologically by radiation, toxic chemicals, hypoxia etc
- lack of antioxidants makes damage more severe
Changes are same whether reversible or irreversible, but reversible less severe.
Examples include:
- “____ ______” : osmotic distrubances with loss of energy-dependant Na pump causing high Na in cell
- “___ ____” : accumulation of lipid vacuoles in cytoplasm caused by disruption of fatty acid metabolism, esp in liver
- “cytoplasmic blebs”
- “disrupted microvilli”
- “swollen mitochondria”
Pic for this in cell injury, degen and death folder.
Changes are same whether reversible or irreversible, but reversible less severe.
Examples include:
- “Cloudy swelling” : osmotic distrubances with loss of energy-dependant Na pump causing high Na in cell
- “Fatty change” : accumulation of lipid vacuoles in cytoplasm caused by disruption of fatty acid metabolism, esp in liver
- “cytoplasmic blebs” (like sacs of membrane containing cytoplasm hanging out of cell)
- “disrupted microvilli”
- “swollen mitochondria”
Pic for this in cell injury, degen and death folder.
After cell injury, death is usually by _____.
______ is uncontrolled and due to external stimuli, and always pathological.
______ is programmed / controlled, usually physiological. Can be pathological though, eg in a ____ ______.
Main difference between two is in _____ the ___ _____ ___ ___ whereas in _____ they do not.
After cell injury, death is usually by necrosis.
Necrosis is uncontrolled and due to external stimuli, and always pathological.
Apoptosis is programmed / controlled, usually physiological. Can be pathological though, eg in a viral infection.
Main difference between two is in necrosis the cell contents leak out whereas in apoptosis they do not.
_____ = necrosis caused by a loss of blood supply
Infarction
Histological changes in necrosis:
- ___ ______
- vacuolation
- disruption of _______ and organelles
- release of cell contents (enzymes released can cause ______ _____ and thus ___ ______)
- DNA disruption
Histological changes in necrosis:
- cell swelling
- vacuolation
- disruption of membrane and organelles
- release of cell contents (enzymes released can cause adjacent damage and thus acute inflammation)
- DNA disruption
Types of necrosis:
- _______ : firm, tissue maintained. Can be _______ (excess blood) due to venous blockage or ________ (lack of blood supply) which affects larger area.
- ________ : tissue becomes liquid and structure lost. Examples inc cerebral infarct, infective abscess.
- ______ : combination of _______ and _______, appears “cheese like”. Usually for granulomatous inflammation, esp TB in lung.
- ___ : due to action of lipases on ____ ____
Types of necrosis:
- Coagulative : firm, tissue maintained. Can be haemorrhagic (excess blood) due to venous blockage or gangrenous (lack of blood supply) which affects larger area.
- Colliquitive : tissue becomes liquid and structure lost. Examples inc cerebral infarct, infective abscess.
- Caseous : combination of coagulative and colliquitive, appears “cheese like”. Usually for granulomatous inflammation, esp TB in lung.
- Fat : due to action of lipases on fatty tissue
Necrosis causes release of cell contents which activates _______ and causes damage.
- Either ____ with removal of stimulus and then healing+repair
- Or _____ with persistence of stimulus (_____ ________).
Necrosis causes release of cell contents which activates inflammation and causes damage.
- Either acute with removal of stimulus and then healing+repair
- Or chronic with persistence of stimulus (chronic inflammation).
__________ apoptosis:
- __________, deletion of cell populations
- cell deletion in growing cell populations to maintain constant number eg epithelium
- deletion of inflammatory cells after immune response
- deletion of self-reactive _______ in the _____.
________ apoptosis:
- ____ ________, eg cytotoxic T-lymphocytes
- DNA damage
- hypoxia/ischaemia
Physiological apoptosis:
- embryogenesis, deletion of cell populations
- cell deletion in growing cell populations to maintain constant number eg epithelium
- deletion of inflammatory cells after immune response
- deletion of self-reactive lymphocytes in the thymus
Pathological apoptosis:
- viral infection, cytotoxic T-lymphocytes
- DNA damage
- hypoxia/ischaemia
Morphology of apoptosis:
- ___ _____
- _____ ______ (this is when nucleus is packaged up, does not happen in necrosis)
- stages of this^ can be found in pics folder
- __ ______ and _______ remain intact (unlike necrosis)
- _______ ___ form and break off to form apoptotic bodies which are _______ by _______.
Morphology of apoptosis:
- cell shrinkage
- chromatin condensation (this is when nucleus is packaged up, does not happen in necrosis)
- stages of this^ can be found in pics folder
- cell membrane and mitochondria remain intact (unlike necrosis)
- cytoplasmic blebs form and break off to form apoptotic bodies which are phagocytosed by macrophages.
_______ = abnormal accumulation of substances
Location may intracellular, extracellular or in connective tissue.
Composition:
- normal _______ substances (eg CHO/protein/lipid products of metabolism, pigments, mix of both)
- foreign _______ substances (eg pigments, industrial material)
Depositions = abnormal accumulation of substances
Location may intracellular, extracellular or in connective tissue.
Composition:
- normal endogenous substances (eg CHO/protein/lipid products of metabolism, pigments, mix of both)
- foreign exogenous substances (eg pigments, industrial material)
Deposition examples
Endogenous intracellular:
- ______
- _________
- lipid, inc cholesterol
also for endo intra,
- ‘storage disease’ eg alpha-1-antitrypsin in liver
- ‘degeneration products’ eg lipofuscin (a ‘wear-and-tear’ pigment)
Endogenous extracellular:
- ______
- _____
- calcium
Exogenous intracellular:
- _____ _______
- carbon (_______ - carbon in lungs)
- ______
Exogenous can be extracellular too.
Deposition examples
Endogenous intracellular:
- melanin
- haemosiderin
- lipid, inc cholesterol
Endogenous extracellular:
- amyloid
- fibrosis
- calcium
Exogenous intracellular:
- tattoo pigment
- carbon (anthracosis - carbon in lungs)
- asbestos
Exogenous can be extracellular too.
_____ = ____ protein fibrils form ______ aggregates, leads to accumulation of abnormal protein extracellularly. _____ is a pattern which can be produced by multiple proteins. Can be _____ or ______.
Occurs due to production of an ______ _____ or excessive production of a ____ _____.
Resembles fibrosis but without prior inflammation.
____ ___ stain is used as fibrils will stain pink.
Pics in folder.
Amyloid = soluble protein fibrils form insoluble aggregates, leads to accumulation of abnormal protein extracellularly. Amyloid is a pattern which can be produced by multiple proteins. Can be systemic or localised.
Occurs due to production of an abnormal protein or excessive production of a normal protein.
Resembles fibrosis but without prior inflammation.
Congo Red stain is used as fibrils will stain pink.
Pics in folder.
Accumulation of excessive amounts of normal protein:
- __ _____ : immunoglobulin ____ chain, produced in B cell neoplasms (eg ____ _____)
- __ _____ : serum amyloid associated protein (normal acute phase protein made by liver), produced in prolonged ____ _______ (eg rheumatoid arthritis)
These are both examples of _____ deposition.
Accumulation of excessive amounts of normal protein:
- AL Amyloid : immunoglobulin light chain, produced in B cell neoplasms (eg multiple myeloma)
- AA Amyloid : serum amyloid associated protein (normal acute phase protein made by liver), produced in prolonged chronic inflammation (eg rheumatoid arthritis)
These are both examples of systemic deposition.
Accumulation of abnormal protein:
Many types, for example in ______.
These amyloids of abnormal proteins are often ______.
Accumulation of abnormal protein:
Many types, for example in Alzheimer’s.
These amyloids of abnormal proteins are often localised.
Pathological calcification,
aka _______ of calcium salts.
Can be:
- _______, deposition in abnormal tissue with _____ serum calcium
- _______, deposition in normal tissue with _____ serum calcium (often in blood vessels, affects function)
Serum calcium can be raised with raised ________ ____ or may be systemic with _____.
Pathological calcification,
aka deposition of calcium salts.
Can be:
- Dystrophic, deposition in abnormal tissue with normal serum calcium
- Metastatic, deposition in normal tissue with raised serum calcium (often in blood vessels, affects function)
Serum calcium can be raised with raised parathyroid hormone or may be systemic with cancer.
Which of the following statements about cell injury is NOT true?
- Its pathogenesis involves free radicals/reactive oxygen species
- It may be reversible or irreversible
- Mitochondrial damage is rare
- It may lead to cell death
3.
Which of the following statements about necrosis is NOT true?
- It is uncontrolled
- The cell contents leak out
- Necrosis may be physiological
- Infarction is one form
3.
Which of the following is NOT a form of necrosis?
- Apoptosis
- Caseous
- Coagulative
- Colliquitive
1.
Which of the following statements about apoptosis is true?
- It is always physiological
- The cell contents leak out
- It occurs during embryogenesis
- It is rare in normal lymphocytes
3.
