Cell Injury and Cell Death Flashcards
Cell Injury
- Can be reversible (which allows the cell to recover)
- Can be irreversible (which causes cell death)
Morphologic characteristics include:
- Blebs and excessive cell swelling
- Disruption of organelles
- Autophagy by lysosomes
- Karyolysis or karyorrhexis
Calcium Influx
Hallmark of irreversible cell injury or cell death is massive calcium influx
Necrosis
Cell death due to injury
Apoptosis
Cell death due to physiological turnover of cells
Cellular Adaptation
- Ability of cell to respond to stress
- Intended to preserve cell viability
- Improve the functional capacity of the cell
- Can stress cells if homeostasis isn’t returned quickly
- Usually reversible at least initially
Atrophy
Physiological Atrophy
Comes from changes to the functional demands on a cell
Pathologic Atrophy
-Comes from pathologic stimuli
Disuse Atrophy
Decreased workload
Denervation Atrophy
Loss of nerve connectiom
Ischemic Atrophy
Loss of blood supply
Hypertrophy
- Increase in cell size due to stress
- Increase of cell components
- Caused by hormonal stim. (pregnancy)
- Increased functional demand (muscle)
- Initially increases functional capacity of the affected organ
- Results in eventual inability of the organ to compensate for the increased workload
Hyperplasia
- Increase in number of cells
- May be caused by pathologic or physiological stim
Non Dividing Cells
- Cardiac Myocytes
- Cannot undergo hypertrophy
Dividing Cells
- Epithelial Cells
- Can divide and may undergo hyperplasia and hypertrophy
Metaplasia
- Reversible process in which mature cell types are replaced by less mature cell types
- Most often found in epithelial cells and connective tissue
- Associated with the predisposition to cancer
- Seen in smokers: columnar ciliated epithelial cells are replaced with flat squamous epithelial cells
Dysplasia
-Disordered growth and maturation of the cellular components of a tissue
-Associated with potential cancer
-Disrupts the homogenous appearance of tissue by causing:
*Change in cell size and shape
*Nuclear enlargement, irregularity, and hyperchromatism
*A disarray in the arrangement of cells within the
epithelium
-most often associated with hyperplastic squamous epithelium (e.g., epidermal actinic keratosis)
-Ulcerative Colitis
-If curbed, can regress and go back to a healthier state
