MoD Flashcards
What is Hypoxia?
Oxygen Deprivation
What happens in Reversible Hypoxic injury?
Reduced O2 reduces ATP production, this slows the Na+ pump, Cell swelling by osmosis, increase in Glycolytic pathway which increases Lactic acid, decreased pH causes clumping of nuclear chromatin, Ribosomes detach due to lack of energy, build up of fat + denatured proteins
What happens in Irreversible Hypoxic injury?
Ca2+ enters through damaged plasma membrane, Ca2+ conc. rises, activates ATPases, Phospholipases, Proteases, Endonucleases, this reduces ATP and damages membrane and DNA
What is the marker for Cell damage in the Liver?
Transaminase
How does Cyanide work?
Blocks Oxidative Phosphorylation by binding to Mitochondrial cytochrome oxidase
What is the Fenton reaction and why is it important?
Fe2+ + H2O2 -> Fe3+ + OH- + OHr, Its important in bleeding as when blood is around iron is availible to make FR’s
Which enzyme is involved in the conversion of Hydroxyl groups to Hydrogen Peroxide?
Superoxide Dismutase
Which enzymes are involved in the removal of H2O2?
Catalases and Peroxidases
What are the Free Radical Scavangers?
Vitamines A, C and E, Glutathione
Which storage proteins sequester Iron and Copper?
Transferrin and Ceruloplasmin
What do Heat Shock Proteins do?
Recognise any misfolding of proteins and repair them, if they cant they destroy the misfolded protein
What changes can you see of cell injury under a light microscope?
Swelling (reduced pink staining due to increase in water), Increased staining due to ribosome detachment. Chromatin clumping, Shrinkage, fragmentation, dissolution of nucleus
What cell changes do you see under an electron microscope in Reversible cell injury?
Swelling, Blebbing, Clumping chromatin, Seperation of ribosomes
What cell changes do you see under an electron microscope in irreversible cell injury?
Shrinkage, fragmentation, dissolution of Nucleus, Rupture of Lysosomes, Membrane defects, Lysis of ER, swollen Mitochondria
What is Oncosis?
Cell death by swelling
What is Necrosis?
Morphological changes that occur after cell death
When does Coagulative Necrosis happen?
When there is more protein denaturation than active proteases being released, cell proteins uncoil and become less soluble
When does Liquifactive Necrosis take place?
When the release of active Proteases is greater than the protein denaturation
When is Caseous Necrosis commonly seen?
TB in the Lungs
What is fat Necrosis and when is it commonly seen?
Destruction of adipose tissue, commonly seen in acute Pancreatitis as lipases are released in inflamation
What is Gangrene?
Necrosis visible to the naked eye
Whats the difference between Red and White infarcts and when do they both occur?
There is no Haemorrhaging into white infarcts, these are typically found in solid organs. There is Haemorrhaging into red infarcts and they are found in organs with poor stromal support
What does the severity of an infarct depend on?
Alternate blood supply, How quickly ischemia takes place, how venerable the tissue is to hypoxia, O2 content of the blood
Which molecules can be released from injured cells?
Potassium, Enzymes, Myoglobin