definition of death, signs of death, necrosis, apoptosis

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Definition of death, signs of death, necrosis, apoptosis

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PowerPoint bemutatóClinical death - temporary cessation of
circulation/oxygen supply
(loss of oxygen < 4-5 min)
Biological death - irreversible
Determination of death is a task of medical doctor
Obligatory administrative tasks:
(DNA-fragmentation)
Two major mechanisms: - death receptors
- mitochondrial route
The same agent may produce either apoptosis or necrosis, depending on its concentration
Necrosis
Circumscribed death of tissue/organ within a living organism
Cause: The strength of the harmful factor exceeds the compensatory capacity of the given tissue
a./ endogeneous causes:
- hypoxia (brain, centers of malignant tumors)
- neural effects (Raynaud-phenomenon, diabetes mellitus)
- immunological causes (immune complexes, C3-activation)
- mechanical causes (prolonged compression) – decubitus
b./ exogeneous causes:
Variable
- depends on the given tissue/organ
irreversible damage: brain 4-5 min
myocardium 20-30 min
limbs 2-3 hours
Site of damage:
- production and accumulation of free radicals (ROS)
- increased membrane permeability
- resorption of the membrane between fingers syndactyly
APOPTOSIS INDUCTION IS AN IMPORTANT THERAPEUTIC GOAL IN CASES OF MALIGNANT TUMORS
Necrosis and apoptosis sometimes