Necrosis & Heat Shock Proteins Flashcards
What is necrosis?
Pathological, unregulated cell death in living tissue causing the release of intracellular contents leading to inflammation
What two processes are involved in necrosis of a cell?
Denaturing of proteins and enzymatic digestion of organelles
What is apoptosis?
Regulated, programmed physiological cell death where the cells own enzymes degrade proteins and the cell is removed by phagocytosis
What are the causes of apoptosis?
Embryogenesis
Hormone-dependent involution in the adult
Cell deletion in populations of cells with normal turnover (eg. Skin, uterine lining)
What is the morphological pattern of death by apoptosis?
Cell shrinkage
Chromatin condensation
Apoptotic bodies (blebbing)
Phagocytosis of apoptotic cells
What form of cell death plays a role in the pathogenesis of neoplasms?
Apoptosis
What are the major differences between necrosis and apoptosis?
Apoptosis = Regulated, normal cell death, Membrane remains intact
Necrosis = Pathological, unregulated cell death
- Membrane bursts leading to release of intracellular contents
- CAUSES INFLAMMATION
What is coagulative necrosis?
Cell death due to ischemia where the outline of the cell remains for days as organelles fade
What is the only form of infarct or ischemia that causes liquefactive necrosis?
Cerebral infarct (stroke)
What is liquefactive necrosis?
- Cell death due to a microbial infection such as a bacterial or fungal infection
- often causes abscesses and high PMNs (Neutrophils) and results in loss of cell architecture
What pathologies does liquefactive necrosis occur in?
Bacterial pneumonia, cerebral infarct (Stroke), acute bacterial meningitis
Liquefactive necrosis is often associated with what morphological pattern of inflammation?
Suppurative
What is an abscess?
A walled off area of liquefactive necrosis by fibrous connective tissue
What type of white blood cell is commonly present in liquefactive necrosis?
Neutrophil (PMNs)
What is gangrenous necrosis?
- Death of body tissue due to loss of blood flow commonly followed by a bacterial infection (wet gangrene) usually in the extremities (feet, hands, legs, arms)
- characterized by conspicuous colour change