Responses to Cell & Tissue Injury Flashcards
Induction of Apoptosis
Physiological
Pathological
Induction of Necrosis
Pathological
Extent of Apoptosis
Affects single cells
Extent of Necrosis
Affects cell groups
Biochemical events in Apoptosis
Energy dependent, fragmentation of DNA
Biochemical events in Necrosis
Abnormal ion homeostasis
Cell membrane integrity state in Apoptosis
Maintained
Cell membrane integrity state in Necrosis
Lost
Morphology of Apoptosis
Cell shrinkage and fragmentation
Morphology of Necrosis
Cell swelling and lysis
Inflammatory response in Apoptosis
None
Inflammatory response in Necrosis
Usual
Fate of dead cells in Apoptosis
Phagocytosed by neighbouring cells
Fate of dead cells in Necrosis
Phagocytosed by inflammatory cells
Causes of cell death
Sublethal injury
Hydrophobic change
Lethal injury
Normal cell death - discrete
Causes of reduced apoptosis
Neoplasia
Autoimmune disease
Virus infection
Causes of increased apoptosis
Neurodegenerative disorders
HIV infection of T lymphocytes
Coagulative necrosis
Most common type
Initially firm then soft
Colliquative necrosis
Liquefaction with formation of cystic spaces
Caseous necrosis
Characteristic of TB
Gangernous necrosis
Gangrene
Fibrinoid necrosis
The death of cells in small blood vessels.
Associated with severe, accelerated hypertension.
After injury what 3 categories can cells be divided into ?
Labile
Stable
Permanent
Which 2 cell types can be replaced once lost ?
Labile and Stable
