cell injury Flashcards
The two most important requirements for normal cell functions are?
- Intact membranes
2. Energy
When does cell injury become irreversible??
- When calcium influx further damages membranes
- Necrosis (cell death) causes DYSTOPHIC CALCIFICATION which increases intracellular Ca+
types of necrosis?
Coagulative (firm and swollen) and Liquefactive (neutrophils liquify tissue)`
Define infarciton
Obstruction of the blood supply to an organ or region of tissue typically by thrombus or embolus
What are the special types of necrosis? Explain them briefly
- Caseous (cheese-like)
- Gangrenous which is a combination of ischaemia (related to reduced blood flow) and infection. Dry and wet gangrene exist.
o ‘Wet’ gangrene= liquefactive necrosis
o Can often produce gas
o Dry gangrene= coagulative necoris - Fat necrosis- characterised by white, chalky areas (calcium fatty acids), due to the action of lipases released into adipose tissue eg pancreatic necrosis trauma.
List some morphological differences between oncosis and apoptosis
Oncosis involves groups of cells while apoptosis involves individual cells. There is systemic inflammation in oncosis, not in apoptosis. In Necrosis cells swell and lyse while in Apoptosis cells bud of and keep membrane intact.
Why is meat hanged?
Meat is hanged so that autolysis occurs and meat matures (softens)
List Post Mortem artefacts
- Liver mortis–> Hypostatic congestion
- Blood clots- in heart specially
- Haemoglobin imbibition–>where RBC diffuse and breakdown causing staining
- Bile Staining–>biles escaped glall bladder since no longer any barriers
- Dilated intestines–> Due to gas build up (bacterial fermentation/invasion)
- Barbiturate crystal precipitation- white speckles on heart
Define oedema
Excessive extracellular water in the intertitial fluid space. COngestion can lead to oedema
