Cell injury Flashcards
Requirements for steady state of a cell
- Intact genome - preservation of normal DNA templates
- Integrity of metabolic pathways - normal enzyme content
- Intact membranes and transmembrane proteins
- Adequate metabolites – adequate supply of substrates and oxygen
Types of injury -Acquired
- Hypoxia / anoxia
- Reoxygenation injury due to free radical formation
- Physical agents, e.g. mechanical trauma, thermal injury (burns and deep
- cold), ionising radiation, sudden changes in atmospheric pressure, electric shock
- Drugs, chemicals, poisons
- Immunological reactions
- Infectious organisms and their products
- Nutritional imbalances
Types of Injuries - Congenital
Inborn errors of metabolism
Chromosomal defects e.g. Down’s syndrome, sickle cell anaemia
Target sites for injuries
Cell membranes
Nucleus
Metabolic pathways
Essential metabolites
What agents can cause destruction to the cell nucleus?
Injurious agents
Free radicals
Radiation
Cytotoxic agents/toxins
What is the result of damage to the nucleus
What is in the nucleus and what will happen to it
DNA damage or loss
What injurious agents target metabolic pathways or enzymes?
What damages them?
Toxins or poisons
What happens if metabolic pathways are disrupted?
Disruption in protein synthesis
What is a common cause of membrane damage?
Free radicals
3 Examples of metabolites that can be deficient and cause cell injury
Oxygen
Glucose
Hormones
4 cellular adaptations
Hypertrophy
Hyperplasia
Atrophy
Metaplasia
Hypertrophy
increase in size of cells
Hyperplasia
increase in number of cells
Atrophy
acquired diminution in size of organ or tissue due to decrease in size and number of cells
Metaplasia
reversible change where one adult cell type (epithelial or mesenchymal) changes to another adult cell type
