2 - Cellular Damage & Necrosis Flashcards
5 ways cells adapt to change
- Atrophy
- Hyperplasia
- Dysplasia
- Hypertrophy
- Metaplasia
- neoplasia (malignancy)
Change in cell size or #
Hyperplasia, hypertrophy, atrophy
Change in cell type
Metaplasia, dysplasia
Atrophy
Decrease in the size of an organ or body part due to the shrinkage in the size of its cells. Caused by reduced use, insufficient nutrition, aging
Hypertrophy
Increase in the size of an organ/tissue mass due to an increase in the size of the existing cells. Caused by increased workload on the organ/body part.
Hyperplasia
Increase in the size of an organ/mass due to an increase in the number of cells.
Metaplasia
Reversible change when one adult cell type is replaced by another adult cell type. Usually in response to: chronic irritation/inflammation/infection
or may be a precancerous change
Dysplasia
Tissue in which cells vary in size & shape. Usually in response to: chronic irritation/inflammation/infection
or may be a precancerous change
Anaplasia
Refers to cells that are undifferentiated - associated with malignancy
Hypoxia caused by…
- Ischemia - decreased blood supply to a part
- ⇊ O₂ in the air - altitude
- ⇊ O₂ of blood - respiratory disease
- ⇊ O₂ carrying capacity of blood - anemia
Physical agents of cellular injury
Mechanical forces, temperature extremes, electrical forces, radiation injury, chemical toxins, nutritional imbalances
Outcomes of cellular injury
- Reversible: if factor causing damage is removed quickly the cell may be able to recover
- Irreversible: if noxious factor remains, damage becomes irreversible → cellular death (necrosis)
Events after cellular death
- nucleus disintegrates
- cells undergo lysis or dissolution
- release enzymes
- enzymes can cause inflammation and damage
- enzymes can diffuse into blood
Infarction
An area of cell death resulting from lack of oxygen
Necrosis + types
Death of cells/tissue within a living body
- liquefaction
- coagulative
- caseous
