Cell Injury Flashcards
Three causes of hypoxia
Reduced flow to organs (ischaemia)
Decreased oxygenation of the blood
Decreased oxygen carrying capacity
Define necrosis
Changes that occur after cell death in living tissue for 4-24 hours
Define apoptosis
Programmed cell death
What is ischaemia
An inadequate blood supply or part of body
What four things happen in necrosis
Denaturing of intracellular proteins
Cells unable to maintain membrane integrity
Enzymatic digestion by lysosomes
Host response takes hours to develop
What are the five main types of necrosis
Coagulative Liquefactive Fat Caseous Fibrinoid
In structure, What are the 5 reversible and 2 irreversible changes that occur
Swelling Chromatin clumping Autophagy Rinosome dispersal Blebs
Nuclear changes
Lysine rupture
Define infarct
Necrosis due to ischaemia
What is the difference between white and red infarct
Depends on the amount of haemorrhage
White is occlusion of the end artery, no peripheral blood supply leaving the area with no blood - eg kidney
Red is occlusion of blood vessel leading to build up of blood which all haemorrhages at once. Eg bowel
Describe features of coagulative necrosis
Commonest form Occurs in most organs Result in protein denaturation White appearance - texture firm and then soft later Nuclear and cytoplasmic detail lost Neutrophil can infiltrate
Describe features of liquefactive necrosis
Usually seen in brain
Seen in infections resulting in abscess formation
Degradation of tissues by enzymes
Material is dreamt yellow due to dead leukocytes - pus
Features of caseous necrosis
Cheese like appearance
Amorphous debris surrounded by histocytes resulting in granulomatous inflammation
Give features of fat necrosis
Destruction to adipocytes as consequence of trauma or secondary release of kinases from damaged pancreatic tissue
fatty acids react with ca to form white deposits in fatty tissue
Seen in breast tissue and can mimic breast Tumour in radiology
Give features of Fibrinoid necrosis
Usually seen in immune reactions involving blood vessels
Deposits of immune complexes together with fibrin that has leaked out of vessels
Bright pink and amorphous appearance in HE
Name three types of gangrene and their differences
Wet -
Dry -
Gas -
