The nature and mechanism of inflammation

THE NATURE AND MECHANISM OF INFLAMMATION Inflammation may be defined as a series of localized tissue responses to foreign stimuli, which may be biological (e.g. bacteria, fungi, viruses), chemical (e.g. croton oil) or physical (e.g. X-rays, ultra-violet light). Apart from external stimuli, it now appears than an endogenous factor, the autoimmune reaction, may initiate an inflammatory response. 

A considerable amount of research has been aimed at the identification of these intermediate factors. Several naturally occurring substances such as histamine, 5-hydroxytryptamine, bradykinin and certain plasma globulins have been shown to have appropriate pharmacological properties. To prove that such substances have a role in producing inflammatory changes is, however, difficult and the likelihood of their doing so must be decided by a careful assessment of the evidence. A detailed analysis of the mechanism of 

Chronic inflammation is essentially a reparative process in which various types of cell, other than the polymorphonuclear leucocyte, invade the area and in which connective tissue is laid down to replace necrosed parenchymal tissue. 

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