1 Flashcards
What is cell injury defined as?
A variety of stresses a cell encounters as a result of changes to its internal and external environment
What are the two types of cell injury?
- Reversible (sublethal damage)
- Irreversible (lethal damage)
What is hypoxia?
Not enough oxygen going to the brain
What is ischemia?
Reduced flow of blood to certain tissues, leading to hypoxia
Name a toxin that can cause cell injury.
- Ethanol
- Cigarette smoking
What are some infectious agents that can lead to cell injury?
- Bacteria
- Virus
- Parasites
What are some genetic abnormalities that can lead to cell injury?
Aging and changes in metabolism
What are some physical causes of cell injury?
Trauma
What are the changes to the nucleus during cell injury?
- Pyknosis
- Karyorrhexis
- Karyolysis
What happens to ATP levels during cell injury?
ATP levels are reduced, leading to decreased Na+/K+ ATPase activity
What is anaerobic glycolysis and its consequence in cell injury?
Increased anaerobic glycolysis leads to glycogen depletion and increased lactic acid
What is the main characteristic of irreversible cell injury?
Severe membrane damage in cell and organelle membranes
What is cellular adaptation?
Reversible changes in size, number, phenotype, metabolic activity or function of cells in response to changes in their environment
Define hyperplasia.
Increase in the number of cells in a tissue or organ
Define hypertrophy.
Increase in tissue or organ size owing to increase in the size of cells, without the increase in the number of cells
What is atrophy?
Acquired loss of size due to reduction of cell size or number of parenchyma cells in an organ
What is metaplasia?
Reversible change in differentiation from one type of fully differentiated cell type to another
What is dysplasia?
Abnormal maturation of cells resulting in change in shape, size, and organization
What are two examples of metaplasia?
- Squamous metaplasia in the bronchus due to smoking
- Columnar metaplasia in Barrett’s esophagus
What are the types of cell death?
- Programmed
- Non-programmed
What is necrosis?
Unprogrammed death of cells or tissue in a living organism, inciting an inflammatory reaction
What characterizes coagulative necrosis?
Dead tissue initially swollen and firm, but later becomes soft due to digestion by macrophages
What is liquefactive necrosis?
Occurs in the CNS where necrotic neural tissue undergoes liquefaction following stroke or trauma
What is caseous necrosis?
Tissue appears soft, white, and friable, resembling cottage cheese, often associated with tuberculosis
