Definitions Flashcards
Define Apoptosis.
Cell death induced by a regulated intracellular program where a cell activates enzymes that degrade is own nuclear DNA and proteins.
Define Necrosis.
The morphologically changes that follow cell death in living tissue, largely due to progressive degeneration action of enzymes. Cell death is due to disease, injury or failure of blood supply.
Define regeneration.
The replacement of dead or damaged cells by functionally differentiated cells derived from stem cells.
Define haemostasis.
Natural ability to arrest bleeding, e.g. by vascular spasm and blood coagulation, or by artificial means such as ligating a blood vessel. This system prevents death from minor bleeds.
Define thrombosis.
Solid mass of coagulated blood formed within the circulation.
Define embolism.
Fluid or solid mass mobile within a blood vessel and capable of blocking its lumen.
Define atheroma.
Accumulation of lipid in the intima of the artery. Causes narrowing of the lumen and weakened vessel walls.
Define atherosclerosis.
Atheroma causing hardening of arteries.
Define arteriosclerosis.
Hardening of the arteries caused by any condition.
Define hypertrophy.
An increase in tissue/organ size by an increase in cell size. Cells become bigger as they contain more structural components.
Define hyperplasia.
An increase in tissue/organ size by an increase in cell number. Note, there is also a decrease in cell loss by apoptosis.
Define atrophy.
Physiological or pathological cellular/organ shrinkage. Often involves apoptosis.
Define hypoplasia.
Decrease in the development of an organ due to a decrease in the number of cells.
Define metaplasia.
A reversible change in the character of a tissue from one mature cell type to another.
