As just described, innate or nonspecific immunity revolves around natural barriers and secretions and activities that protect us in a non-specific way. Consider this to be "zone defense", where any pathogen or invader or foreign substance is equally-capable of activating the process and all are treated in the same way. This is in contrast to adaptive or specific immunity, where the immune reaction is very specific and tailored to the offending invader. This is more like "man-to-man defense" because the overwhelming majority of specific immune cells (T-cells and B-cells) do nothing during an invasion by a pathogen - only the clone of cells whose cell surface receptor is a perfect match for the antigen of the pathogen is going to be responding to the pathogen. Like boys at a 7th grade school dance, most cells sit around and are not engaged in the activities; only the clone of cells with surface receptors perfectly fitting the invading antigen are committed to "getting up and dancing".
The process is really quite intricate, involving the participation of macrophage and "helper cells" and other entities. In the end specific cytotoxic T-lymphocytes (killer T-cells) recognizing that unique foreign antigen find cells exhibiting the antigen and destroy them (a video at Howard Hughes Medical Institute website shows this). The process of first exposure to the antigen resulting in ultimate production of abundant antibodies can take 10-14 days (the reason why your immunizations for things like the flu do not provide protection for a couple of weeks). And just as there are signals and cells involved in ramping up adaptive immunity, there are also those that slow down the process when the infection is no longer a problem. All this is to say adaptive immunity is very focused on a single antigen, involves only the small number of cells able to recognize that antigen, and in doing so produces antibodies and other responses that focus on ridding the body of anything exhibiting that antigen.
To go a little deeper in the study of adaptive immunity, complete Micro Digital Media Exercise 24.
Your instructor will alert you to the documentation s/he expects from this work, whether VUMIEtm 2012 Virtual Lab Report, or MDM Exercise 24, or other.
When you are done, you may be asked to take the quiz over this material.