Cell Adaptation Flashcards
What can cause a cell to become injured?
Free radicals
Ionising radiation
Trauma
Thermal
Drugs
Poisons
Infectious organisms
Ischaemia and reperfusion
What is hypoxia and what is it caused by?
Reduced oxygen delivery to the tissues
Caused by:
- ischaemia
- hypoxemia
- reduced oxygen carrying capacity of the blood
What does hypoxia do to cells in terms of pumps?
ATP required for Ca2+ pump and Na+/K+ pump
Reduced oxygen –> reduced ATP
Na+ retained in cell –> swollen cell
Ca2+ accumulates in cytosol –> activates enzymes and increases mitochondrial membrane permeability –> swollen
How do free radials cause cell damage?
Free radicals have an unpaired electron in the outer shell, so its highly reactive
Causes damage to cell membranes and DNA
How do physical agents cause cell destruction?
Disrupting the membrane
- freezing
- blast injuries
Impairing the function of the cell
- proteins can be denatured by heat
What causes chemical cell damage?
Poisons or drugs
What are the 2 methods of cell death?
Necrosis and apoptosis
What is necrosis?
Pathological cellular death in a living organism
What is apoptosis?
Form of normal or pathological individual cell death characterised by activation of endogenous endonucleases
What is pyknosis?
Shrinkage of the nucleus in a necrotic cell
What is karyorrhexis?
Fragmentation of nuclear material
What is atrophy?
Decrease in size of a tissue/organ/cell
What is hypertrophy?
Increase in cell size without division
What is hyperplasia?
Increase in the number of normal cells
What is metaplasia?
Replacement of one fully differentiated cell type with another
