01 - Cell injury and Cell death Flashcards
(25 cards)
2 types irreversible cell injury
necrosis + apoptosis
Process creating more cells
hyperplasia
Process creating bigger cells
hypertrophy
Transformation one type differentiated cell into another type
Metaplasia
How does smoke affect columnar cilia cells
paralyses stopping mucous clearance
Columnar epith. –> squamous epith.
what causes mechanical disruption to cells
Trauma + Osmotic pressure
what causes energy failures to cells
Oxygen lack + glucose lack + Mitochondrial failure
what causes membrane damage to cells
free radicals
what causes DNA damage or loss to cells
ionising radiation + chemotherapy + free radicals
what causes blockage of metabolic pathways to cells
interruption of protein synth. + resp. poisons + hormone/growth factor lack
what causes issues to membrane integrity to cells
damage to ion pumps + Complement or perforin + bacterial toxins
What are free radicals
VERY reactive mol.
How are free radicals produced
by products from other biochemical reactions
Mechanism of injury by free radicals
damages proteins and nucleic acid by apoptosis
What detoxifies free radicals
superoxide dimutase and antioxidase e.g Vit. A, C & E
how do infectious organisms affect cells
hijacking cell machinery by viral infection –> cell lysis
Then collateral damage by inflammation
Physiological signals inducing apoptosis
embryogenesis
Involution
Elimination of self-reacting lymphocytes
Pathologyical signals inducing apoptosis
DNA/protein damage
Viral infections
Cell killing by cytotoxic T-cells
CHEMO/radiotherapy
What is over expressed in Follicular lymphoma
anti apoptotic BCL-2
inhibits apoptotic cell death causing cells to accumulate
Distinct morphological types of Necrosis
COAGULATIVE - most common
CASEUOUS - tuberculosis
COLLIQUATIVE - brain
GANGRENE - wet and dry
Description coagulative necrosis
denaturation intracytoplasmic protein where dead tissue becomes firm and slightly swollen
(typical of ischaemic injury)
Description colliquative necrosis
neural tissue little supporting tissue thus liquefies upon cell death –> marked by CYST
Brain not have a collagenous tissue framework
Description Caseous Necrosis
charasteric tuberculosis + Cheese like
granulomatous inflammation = dead tissue lacks any structure
Dry gangrene
applies gradual hypoxic coagulative necrosis of lower limbs
