Cell injury Flashcards
List the EIGHT causes of cell injury
Oxygen deprivation Inflammation Chemical Agents Genetics Infection Nutritional imbalances Physical Agents Ageing
What four intracellular mechanisms are particularly vulnerable to cell injury?
Cell membrane integrity
Protein synthesis
ATP Generation
Integrity of the genetic apparatus
Define Atrophy.
Shrinking in the size of a cell or organ by the loss of cell substance.
Define Hypertrophy.
Increase in the size of cells and, consequently, an increase in the size of the organ
Define Hyperplasia
Increase in the number of cells in an organ
Define Metaplasia
A REVERSIBLE change in which one adult cell type is replaced with another
Define Dysplasia.
Pre-cancerous cells which show the genetic and cytological features of malignancy but not invading the underlying tissue
Define Ulcer.
A local defect, or excavation of the surface, of an organ or tissue, produced by sloughing of necrotic inflammatory tissue
What are the two physiological causes of hyperplasia?
Hormonal (e.g. oestrogenic wave of proliferation)
Compensatory
What are two light microscopic changes associated with reversible injury?
Fatty change
Cellular swelling
Define Necrosis
Confluent cell death associated with inflammation
What are the four types of necrosis?
Coagulative, Liquefactive, caseous and fat
What disease is fat necrosis associated with and why?
Acute pancreatitis - release of lipases that break down triglycerides into free fatty acids and glycerol. Free fatty acids associate with calcium deposits
Describe some uses of apoptosis
Embryogenesis - lumen of intestine
Removal of auto-reactive T and B cells
Cell deletion in proliferating populations
Describe three differences between apoptosis and necrosis.
Apoptosis is an active process (required energy) Apoptosis can be physiological Apoptosis is not associated with inflammation
