The vertebrate immune response is divided into two broad lines of defense. First, barriers (e.g., skin and mucosal membranes) and internal defenses (e.g., inflammation and phagocytic cells) provide a quick but non-specific defense.
Second, the humoral and cell-mediated responses, both of which provide a slower but more targeted response to specific traits presented by a range of pathogens, operate by recognizing and binding to a vast array of specific foreign receptor molecules.
The hallmark feature of the specific immune response is its ability to maintain dynamic homeostasis in the face of natural or artificial agents that disrupt this balance.
The feedback mechanism that governs this system is best characterized as