Cellular Pathology Flashcards
Causes of cell injury
-Physical trauma
-Ischemia/hypoxia
-Chemical agents
>poisons
-Infectious agents
-Immunological reactions
-genetic defects
-nutritional imbalances
Adaptive responses to cell injury ;reversible changes
• Number
• Size
• Phenotype
• Metabolic Activity
• Function
Two types of adaptive responses
Physiological
Pathological
Physiological adaptations
e.g. hormone-induced enlargement of
breast during pregnancy
Principal adaptive responses are:
• Hypertrophy • Hyperplasia • Atrophy
• Metaplasia
Hypertrophy
- Increased size of cells
- Increased size of organ
-happens when cells are used more(mechanical signals)
Hyperplasia
-Increased number of cells
-Increased organ size
-epithelial cells over prelipilating
-can be caused by drug called phenytoin used to treat epilepsy
Atrophy
-Reduced size of Cells
-Reduced size of Organ
-Diminished function but not dead, caused by decreased work load through: Loss of innervation; Diminished blood supply; Inadequate nutrition; Loss of endocrine stimulation; Ageing; Reduced protein synthesis (due to reduced metabolic activity), increased protein degradation
-
Metaplasia
• Reversible change in phenotype
• Replaced by a cell type which can better
withstand the adverse environment
Reversible Cellular changes in injury
• Cell swelling
• Swelling of organelles
• Lipiddeposition
• Detachmentofribosomes • Lossofmicrovilli
• Clumpingofchromatin
• Surface blebs
Irreversible cellular changes In injury
• lysosomalenzymerelease • Proteindigestions
• Severe cell swelling
• Membranedamage
• Mitochondrial vacuolation • Nuclear changes
Cellular changes in injury
• fattychange
• vacuoles
• cloudyswelling
• Membraneblebbing
• Necrosis
• Nuclear changes
• ERswelling
• lossofribosomes
• loss of specialised membrane structures
• myelinbodies
• condensation of mitochondria
• vacuolisation of mitochondria
