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General Pathology – Seminar 2. Necrosis Atrophy - causes. Jaroslava Dušková Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague http://www1.lf1.cuni.cz/~jdusk/. Death. irreversible damage of the morphological & functional integrity of. cells. organism. Cell Death. apoptosis
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General Pathology – Seminar 2 Necrosis Atrophy - causes Jaroslava Dušková Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague http://www1.lf1.cuni.cz/~jdusk/
Death irreversible damage of the morphological & functional integrity of cells organism
Cell Death • apoptosis • necrosis
Apoptosis • induced (from outside) or • genetically programmed cell death (cell execution / suicide) • logical and functional contrary to mitosis • a system for the removal of unnecessary, aged, or damaged cells
Apoptosis -1 • Triggered by a wide range of stimuli. • Cell surface receptors like Fas or tumor necrosis factor receptor 1 (TNFR1). • Interplay of proapoptotic (Bax, Bad, Bid, Bik, and Bim) and antiapoptotic(Bcl-2 and Bcl-XL)proteins
Apoptosis Morphology • chromatin condensation • cell shrinkage • budding and forming of apoptotic bodies (emission of pseudopodia) • karyorrhexis (not pathognomonic for apoptosis)
Apoptosis Meaning • physiological process necessary for right organ formatting and life course • pathological process leading to organism damage - e.g. atrophy
Apoptosis Ontogenesis intestinal mucose, genit. tract, immune system - T lymphocytes Regeneration of tissues and organs intestinal mucose, blood Physiological involution neonatal adrenal cortex, thymus, breast after lactation period Atrophy preassure, hyperplasia regression, slight ischemia
Necrosis cell deathcaused from external insult
Necrosis Biochemistry • no expression of genes de novo • energy dependent membrane systems damaged hypoxia, toxins • changes in concentrations of ions • increased water volume (oncosis) • autolysis
Necrosis Morphology • pyknosis, karyorhexis, karyolysis • denaturation of proteins - eosinophilia • cell swelling • cell budding (cytoplasmic protrusions)
Necrosis Meaning pathological process leading to a temporary organism damage or death
Necrosis Classification according to the tissue macroscopy: • simple • liquefaction • coagulation + special types: caseation, Zenker´s of waxy appearance
Necrosis - further development: • no death of organism • gangrene sicca (dry g.) humida (wet g.) emphysematosa (gas g.) • demarcation, sequestration regeneration repair
Necrosis - Causes: • chemical • chlorinated hydrocarbons, heavy metal compounds, ethyl- alcohol, aphlatoxins, ... • physical • mechanical trauma, UV light, ionizing radiation, heat, cold, …. • biologic • bacteria, viruses, fungi...
Atrophy diminution of organ or tissue after full development has been attained (versus hypoplasia, aplasia) • simple (x hypertrophy) • numerical(x hyperplasia)
vascular pressure inactivity inanition neurogenic ionizing radiation involution senile postinflammatory endocrine unknown cause Atrophy - causes:
Atrophy - meaning: • may be reversible • loss of specialised structures & hypofunction • clinically silent or unimportant (involution) • clinically apparent • metaplasia, increase of the supportive tissues - pseudohypertrophy