Cell Damage & Cell Death Flashcards
Hyperplasia
Increased number of cells
Hypertrophy
Increased size of cells
Hypotrophy
Decreased size of cells
Hypoplasia
Decreased number of cells [Involution]
Atrophy
Can refer to either decrease in number or size of the cells
During smoking, what happens to the cells in the respiratory tract?
Metaplasia [Reversible] –> Dysplasia [Irreversible and likely to lead to cancer]
Metaplasia: Pseudostratified columnar epithelial cells convert to stratified squamous to withstand the irritation of smoking to the epithelium
Dysplasia: Prolonged irritation causes disordered growth of cells, also likely leading to cancer.
Physiological vs Pathological Response
Physiological response is usually body’s changes to aid itself whereas pathological response is usually when its getting harmed.
Anaplasia
Loss of mature cellular differentiation
4 reversible, EARLY stages when cells undergo stress
- Hydropic changes [swelling of cytoplasm]
- Fatty Changes
- Nuclear chromatin clumping
- Mitochondrial swelling
4 Irreversible, LATE stage changes cells undergo nearing apoptosis
- Pyknosis [Nuclear condensation]
- Karyorrhexis [Nuclear Break up]
- Karyolysis [Dissolution]
Others: lysosomal rupture, amorphous [lack of clear defined shape] densities in MC matrix, disruption of CSM, blebbing of CSM
Late stage apoptotic cells stain more esinophilic or basophilic?
Eosinophilic
due to denatured proteins which are eosinophilic. cancer cells also stain more eosinophilic.
Necrosis vs Apoptosis
Cell Size: Enlarged vs Reduced
Nucleus: Pyknosis, Karyorrhexis, Karyolysis vs Fragmentation into nucleosome size fragments
CSM: Disrupted vs Intact but altered
Cellular contents: Enzymatic digestion + Leakage out of cell vs Intact but released in apoptotic bodies
Adjacent Inflammation: Frequent vs None
Physio/Patho: Invariably Patho vs Usually physio [eliminate unwanted cells] can be patho after some cell injury [dna/protein damage]
No. of cells: More cells [Tissue level] vs Few/Single cells
ATP: passive vs active
8 types of necrosis
liquefactive, caseous, coagulative, suppurative, hemorrhagic, fat, gangrenous, fibrinoid
Autolysis
Death of cells and tissues after the death of the whole
organism
Apoptosis
programmed cell death [either physio or patho]
Necrosis
Defined as death of cells in living tissues characterized
by the breakdown of cell membranes. Always pathological
coagulative necrosis
Form of necrosis secondary to hypoxia or loss of blood supply (ischaemia / infarction). Ghost outlines (cell structure present but with loss of nuclei) of cells seen on light microscopy.
hypoxia –> ischaemia –> infarction –> necrosis
caseous necrosis
“cheesy necrosis” usually occurs after TB infection.
liquefactive necrosis
Used to describe necrosis in the brain post stroke (infarction).
Haemorrhagic necrosis
Used to describe necrosis in organs with dual blood supply eg. Lungs and Liver.
suppurative necrosis
Suppurative necrosis used to describe abscess formation (large collections of neutrophils)
gangrenous necrosis
autoamputation
Makeup of Granuloma [4 cell types]
- epithelioid macrophages
- lymphocytes
- neutrophils
- multinucleated Langhans giant cells
Granulomas are aggregates of epithelioid histiocytes (macrophages) often with central necrosis and seen as multinucleated giant cells surrounded by T lymphocytes and neutrophils.
basis of haemorrhagic necrosis?
occulsion of one blood supply –> ischaemia [lack/reduced blood flow] –> tissue dies –> endothelium lining vessels of 2nd blood supply die even though it has perfusion due to hypoxia –> endothelium ruptures –> loss of vessel endothelial integrity –> haemorrhage
fibrinoid necrosis
Blood vessels.
Fibrin (factor II) is found ONLY in blood, a fibrous protein that is part of the coagulation cascade which helps blood clot.
Fibrinoid necrosis is necrosis with extravascular leakage & agglutination of fibrin.
Appears as a pink ring on histology
