Page 30 - Veterinary Immunology, 10th Edition

VetBooks.ir The Defenders

The defenses of the body, collectively called the immune system,
consist of interacting networks of cells and molecules. For

descriptive purposes, it is convenient to divide these networks into
discrete pathways (Fig. 1.1). Nevertheless, the reader should be
aware that these biochemical and cellular pathways are extensively
interlinked. No immune response is restricted to a single
biochemical mechanism or pathway. The invasion of the animal

body by microbes alters the behavior of many different cell types
and the production of many different molecules. Understanding
immunity requires an understanding of these dynamic

immunological networks. These networks possess redundancies,
regulatory mechanisms, and multiple simultaneous responses
working together to ensure microbial destruction. In addition, the
immune responses are adaptable and adjust their mechanisms
depending upon the nature and severity of the threat. This of

course maximizes their efficiency and minimizes the chances of any
individual microbe successfully evading those defenses.

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