Injuries to cells Flashcards
What is hypertrophy?
Increase in the size of cells, resulting in an increase in the size of the organ
What is hyperplasia?
Increase in the number of cells, resulting in a larger organ
What is atrophy?
Shrinkage of the size of the cell by loss of cell substance
What is necrosis?
Damage to membranes that allows enzymes to digest the cell. Causes local inflammation and is always pathological
What is apoptosis?
Programmed cell death. Causes irreparable damage to the cells protein/DNA or deprives the cell of growth factors.
What is neoplasia?
Mild damage to the DNA (gene mutation). Damage to genes controlling DNA repair making them more susceptible to further change. Damage to genes that control cell division leads to excess division. Mutations accumulate and eventually lead to abnormal cells and eventually into cancer.
What causes cell injury?
Hypoxia, ischaemia, chemical exposure, infection, radiation, lack of nutrients, immunological reactions, ageing
Where does coagulative necrosis occur?
Common in the lungs (from pneumonia) and after a heart attack.
Where does liquefactive necrosis occur?
Most commonly occurs in the brain (post-stroke) cells in part of the brain die and turn into a cyst.
Where does caseous necrosis occur?
TB and caseating granulocytes
Which mechanisms does apoptosis use?
Mitochondrial pathway (intrinsic pathway) Fas (death) receptor pathway (extrinsic pathway)
