COPR Advanced Care Paramedic (ACP) Practice Exam

Adaptive immunity has two main arms: humoral immunity and cellular (cell-mediated) immunity. Humoral immunity is driven by B cells that become plasma cells and produce antibodies circulating in the blood and extracellular fluids. These antibodies bind pathogens or toxins, neutralize them, mark them for destruction, and can activate complement. Cellular immunity is led by T cells, including helper T cells that orchestrate the response and cytotoxic T cells that destroy infected or abnormal host cells. This division captures how the adaptive system handles pathogens in different contexts: antibodies mainly tackle extracellular threats, while T cells deal with infected cells and coordinate the overall response.

Other terms don’t describe subdivisions within adaptive immunity. Innate and adaptive describe broad, first-line versus learned defenses, not internal compartments of the adaptive system. Passive and active refer to how immunity is acquired (transferred vs. produced by the individual) rather than how the adaptive response is organized. Humoral and immunogenic pairs a functional arm with a property (immunogenic) rather than a true subdivision.