What is metaplasia?
Reversible change in which one differentiated cell type is replaced by another
What are the two branches of constitutitonal disease? 3 branches of environmental disease?
Hereditary vs non-hereditary
Dietary, Living external agents, non-living external agents
Compare hypoxia and ischemia
- hypoxia: oxygen deficiency
- ischemia: lack of oxygen delivery due to lack of blood flow
Why is depleted levels of ATP problematic for cells?
- Decrease in membrane transport affecting electrolyte balance (Na/K ATPase, Ca/Mg ATPase)-> Swelling of cell
- Decrease in protein synthesis (ribosomal detachment)
- Increase in anaerobic glycolysis (decreased pH, decreased glycogen) -> (decreased pH causes: ) clumping of nuclear chromatin
How does excess cytosolic calcium affect the cell?
increases activities of ATPase (decreased ATP), phospholipase (decreases phospholipids), proteases [ these first 3 lead to membrane damage], and induces endonuclease release by ER (chromatin damage)
What is necrosis? What are the 2 essential concurrent processes that are involved?
premature death of cells caused by infection/interruption of blood supply
requires enzymatic digestion of cells, and denaturation of proteins
What are the four types of necrosis?
coagulative necrosis, liquefactive necrosis, caseous necrosis, fat necrosis
What is coagulative necrosis?
- dead tissue is preserved for a span of time (ex. myocardial infarction)
- characterized by: intracellular acidosis (which results in denaturation of proteins and enzymes but NOT proteolysis)
essentially: cells are dead but remain undigested
localized area of coagulative necrosis is called an infarct (thus MI)
what is liquefactive necrosis
- often associated with bacterial or fungal infections
- accumulation of inflammatory cells as well as digestion of dead cells, and the presence of pus (white goop)
- gross appearance alteration (white and cheesy) in necrotic area
- tissue structure obliterated
- granulomatous inflammation seen microscopically