Cell injury Flashcards
what is lethal cell injury?
produces cell death
what is sublethal cell injury?
produces injury not amounting to cell death - may be reversible or may progress to cell death
list the 8 causes of cell injury
1) Oxygen deprivation
2) Chemical agents
3) Infectious agents
4) Nutritional imbalances
5) Physical agents
6) Immunological reactions
7) Ageing
8) Genetic defects
oxygen came into nuts, particularly ice age generation
what does the cellular response to injurious stimuli depend on?
- the type of injury
- the duration
- the severity
what do the consequences of an injurious stimuli depend on?
- the type of cell
- the status of that cell
- its adaptability
- its genetic makeup
what 4 intracellular systems are particularly vulnerable and often interlinked?
1) cell membrane integrity
2) ATP generation
3) protein synthesis
4) the integrity of the genetic apparatus (DNA and RNA)
list the 6 cellular adaptations to injury
1) atrophy
2) hypertrophy
3) hyperplasia
4) metaplasia
5) dysplasia
6) apoptosis
what is atrophy?
shrinkage in the size of the cell (or organ) by the loss of cell substance but the same number of cells are present
give 2 examples of atrophy
- brain atrophy (dementia)
- muscle atrophy
what is hypertrophy?
increase in the size of cells and consequently an increase in the size of the organ, caused by increased functional demand or specific hormone stimulation, which can be physiological or pathological
give examples of physiological hypertrophy
- heart size increasing due to pregnancy
- heart size increasing in athletes
- hypertrophy of the uterus during pregancy
give an example of pathological hypertrophy
- heart size increasing to due to raised BP
what is hyperplasia?
an increase in the number of cells in an organ, which can be physiological or pathological
what is physiological hyperplasia?
hormonal or compensatory
what is pathological hyperplasia?
due to excessive hormonal stimulation or growth factor stimulation