Anatomy & Physiology

Anatomy & Physiology Study Guide

Specific Defenses Specific defense, or immunity, is provided by the coordinated activities of T cells and B cells, which respond to the presence of specific antigens. In general, T cells are responsible for cell-mediated immunity (or cellular immunity), which defends against abnormal cells and pathogens inside cells, and B cells provide antibody-mediated immunity (or humoral immunity), which defends against antigens and pathogens in body fluids.

©2018 Achieve Page 286 Another way of classifying immunity is to categorize it as either innate or acquired. Innate immunity is genetically determined; it is present at birth and has no relationship to previous exposure to the antigen involved. Innate immunity stays intact unless broken down by conditions such as AIDS that depress all aspects of specific resistance. Opposite innate immunity, acquired immunity is not present at birth. Acquired immunity creates specific antigens as you become exposed to them. This type of immunity can be active or passive, and these forms can be further divided, depending on whether the immunity is naturally acquired or induced (i.e., you catch a cold or get a flu shot). of 368