Flashcards in Lecture 2 Injuries to cells Deck (36)
Increase in number of cells.
Physiological example of hyperplasia?
Pathological example of hyperplasia?
Endometrial hyperplasia if hormone stimulus persists
Increase in the size of cells
Physiological example of hypertrophy?
Pathological example of hypertrophy?
Heart in hypertension
When one adult cell type is replaced by another adult cell trype
Example of metaplasia?
Chronic gastro-oesophageal reflux
Shrinkage of cell size by loss of substance
Why atrophy happens?
↓ workload. ↓blood supply. Inadequate nutrition. ↓hormone stimulation. Ageing.
Morphology of reversible cellular injury?
Cellular swelling and fatty change.
Damage to membrane allowing enzymes to digest cell.
Necrosis pathological or physiological
4 types of necrosis
Coagulation, liquefactive, caseous, fat.
Programmed cell death pathway. Both pathological and physiological.
How does apoptosis occur?
Cells activate enzymes that degrade cells own DNA and proteins -> death/deprived growth factors. Membrane remains intact, no leaks, phagocytosis removes bits of cell.
Physiological or pathological apoptosis? Embryogenesis
Physiological or pathological apoptosis? Involution of hormone dependent tissues when deprived of hormone.
Physiological or pathological apoptosis? Elimination of cells who have served their purpose.
Physiological or pathological apoptosis? Killing ?harmful cells
Physiological or pathological apoptosis? DNA damage
Physiological or pathological apoptosis? Accumulation of misfolded proteins
Physiological or pathological apoptosis? Atrophy in parenchymal organs after duct obstruction.
Physiological or pathological apoptosis? Cell death induced by cytotoxic T cells
Apoptosis results from the activation of
Fas (death) receptor pathway...
Cell injury by ATP depletion
Occurs from: ↓oxygen and nutrient supply, mitochondrial damage, poisons. Effects: ATP dependent Na2+ pumps, ^lactic acid, Xcalcium pumps& protein damage.
Occurs from: hypoxia, chemical poisons, radiations. Effects: Fail to produce ATP & free radicals
Influx of Ca2+
Occurs from: ischaemia & poisons. Effects: ^intracellular Ca2+ -> enzyme activation -> damage to cellular components. APOPTOSIS.
Occurs from: ^free radicals. Removed by antioxidants. Effects: damage proteins, fat, DNA & create more of themselves.
DNA protein damage
Occurs from: radiation injury/oxidative stress. APOPTOSIS.
Defects in membrane permeability
Effects: ↓phospholipid synthesis (↓ATP). O2 free radicals and lipid breakdown. NECROSIS
Intracellular accumulation of abnormal material examples
Fat in hepatocytes (liver cells) from alcohol use. Cholesterol in SM in atherosclerosis. Protein in alzheimer's and parkinson's disease.
Damage to genes controlling DNA repair ->
susceptible to further change