Beyond the basics: immune response.

The human immune response is arguably among the most difficult processes for an EMS provider to understand. The immune system provides front-line defense to any potentially inflammatory process, with the goal of destroying or inactivating pathogens, abnormal cells and foreign substances. The system includes the thymus, spleen, lymph nodes, lymphoid tissues (as in the GI tract and bone marrow), macrophages, lymphocytes, including B and T cells, and antibodies, among others. On the surface, the skin and stomach acid serve as physical barriers to invasion. This article will primarily concentrate on the immune response to allergies, but will discuss some other immune disorders to illustrate the role of the immune system in common disease processes.