2.11 Cell Injury And Fate Flashcards
What are the two types of cell injury?
Sublethal and lethal
What is lethal cell injury?
One that produces cell death
What is sublethal injury?
Produces injury but not amounting to cell death - may be reversible or even progress to cell death
What are 8 causes of cell death?
- Oxygen deprivation
- Chemical agents
- Infectious agents
- Immunological reactions
- Genetic defects
- Nutritional imbalances
- Physical agents eg trauma or rdiation
- Aging
The cellular response to injurious stimuli depends on…
- type of injury
- duration
- severity of injury
The consequences of an injurious stimuli depend on?
- Type of cell
- Cell status
What are 4 intracellular systems which are particularly vulnerable to cell injury?
- Cell membrane integrity
- ATP generation
- Protein synthesis
- Integrity of genetic apparatus
What is meant by atrophy?
Shrinkage in size of a cell / organ by the loss of cell substance
E.g. shrinking brain in dementia patient or muscle atrophy after denervation
What is meant by hypertrophy?
Increase in the size of the cells
What is a pathological example of hypertrophy?
‘Pathological’ cardiac hypertrophy
Thickening of heart muscle, a decrease in the size of the chambers and the reduced capacity of the heart to pump blood
What is an example of physiological hypertrophy?
Increase in the size of cells of the uterus during pregnancy to accomodate for the foetus
What is meant by hyperplasia?
An increase in the number of cells in an organ
What is the main cause of pathological hyperplasia?
Usually due to excessive hormonal or growth factor stimulation
Describe a physiological example where hyperplasia can occur?
Increased oestrogen stimulation drives the increased proliferation of the endometrial glands leading to increased number of endometrial cells
What is a pathological example of hyperplasia?
Carcinoma – too many cells leading to disease
What is metaplasia?
A reversible change in which one adult cell type is replaced by another
Describe a pathological example of metaplasia?
Barretts Oesophagus - The oesophagus is normally lined with squamous epithelial cells, acid reflux causes these to change to columnar epithelial cells
How can metaplasia in barrets oesophagus be reversed?
Taking antacids