专业术语—口腔生理学术语I2(英文详解)
Inflammation - is a whole complex of events which occur in sequence, in response to injury. Tissue damaged by bacteria, chemicals, heat, trauma etc, release histamine and bradykinin and serotonin which cause an increase in capillary permeability and vasodilation. Both these factors contribute to the formation of a fluid exudate in the damaged tissue, which includes fibrinogen and therefore soon clots into a firm gel. This process has the effect of walling off the bacteria or toxic substances causing the damage, or at least it slows down their spread into surrounding tissues. Local macrophages, begin their phagocytic activity but their numbers are small. Damaged tissues also release interleukin, messengers which are transported all the way to the bone marrow, where millions of leucocytes are stored.. These stores now release leucocytes, mostly neutrophils into the blood. The neutrophils gather at the site of damage because the endothelial cells of the local capillary walls have become sticky to leucocytes. This stickiness is specific for leucocytes and is the work of selectins expressed on the cell membrane of the endothelial cell. The leucocytes begin to catch and roll along the endothelium until they are brought to a standstill. The increased permeability of the endothelial cells allows leucocytes to wriggle out of the capillary and migrate into the damaged area. This migration is also dependent on a process know as chemotaxis, in which cytokine messages from the damaged cells attract the leucocytes to come to their aid. After several days the battle zone is filled with dead bacteria, dead tissue cells, dead neutrophils and macrophages. This dead mass of tissue is called pus. The end of the event may be the gradual resorption of pus by fresh macrophages, or the pus, now under some pressure, may force its way somewhere else. Pus from the apex of a tooth may escape laterally through the alveolar bone and mucosa, where it is recognisable as a "gum boil".Ten days after a foreign protein is detected for the first time, the bodies immune system has mounted a more specific defense. Antibodies are produced by B lymphocytes and T lymphocytes have been alerted to the invasion.
