Cell Injury Flashcards
3 causes of cell injury
Acquired (after birth via enviro)
Genetic (genetic base sequence)
Congenital (during foetal development)
Hypoxia-Inducible Factor 1
Released during Hypoxic Stress
New blood vessel formation
Stimulates cell survival
Ischaemia-reperfusion Injury
Blood flow is returned
Leads to oxidative damage
What type of cells replicate continuously?
Squamous
What type of cells replicate on demand
Liver
What type if cells never replicate
Nerve cells
Increased cellular activity leads to what two things?
Hypertrophy
Hyperplasia
Decreased cellular activity leads to what?
Atrophy
What 4 proteins causes the increase in synthesis of contractile proteins?
TGF-B
IGF-1
endothelial-1
Angiotensin-2
What type of cells can enlarge due to TGF-B?
Skeletal / Cardiac
Name the 3 types of hyperplasia
Pathologic (excess hormones or GF)
Compensatory (regeneration of liver from hepatectomy)
Physiologic (hormonal)
Name two types of atrophy
Physiologic - decreased size of uterus after birth
Pathologic - degeneration of muscle/Blood supply
What pathway does the atrophy go through?
Ubiquitin-Proteasome
Metaplasia refers to what substitution?
One cell type for another
What are lost during metaplasia?
Protective mechanisms
Columnar—> squamous in smokers
Where does dysplasia often occur?
Metaplastic epithelium
Coagulatative Necrosis
Dead tissue preserved
No proteolysis occurs
Ischaemia
Liquefactive Necrosis
Digestion of dead cells —> liwuid viscous agent
Accumulation of leukocytes / Pus
Caseos Necrosis
Collection of fragmented /Lysed cells
Foci of TB infection
Gamgrenous Necrosis
Loss of limb
Due to lack of BS
Fat Necrosis
Damage to pancreas
Lipases released which convert fat —>glycerol + FA
Cell death in fatty tissue
Name the two situations of apoptosis
Physiologic-eliminates cells which are no longer needed (embryogenesis)
Pathologic -DNA damage + Accumulation of miss folded proteins
Deficient apoptosis
Mutations on p53
Excess apoptosis
Alzheimers
Whats leaked out of mitochondria during intrinsic apoptosis?
Cytochrome C
What stops intrinsic Apoptosis from occurring?
Growth factor binding to cell membrane
Name the 4 stages of apoptosis
DNA fragments
Cytoplasm shrinks and membrane Blebs
Contents packed apoptotic bodies
Phagocytes engulf
What causes hypertrophy in terms of work?
Increased functional demand
What causes DNA damage this pathologic apoptosis?
Free radicals / radiation / hypoxia
What do chaperones do?
DNA repair
What type of virus can degrade p53 function
HPV type 16
