Host Defenses Nonspecific Resistance Specific Resistance (Responses of the Immune System, Chapter 17) First line of defense Second line of defense Third line of defense 。Intact skin ·Phagocytic white Specialized lymphocytes: 。Mucous membranes blood cells B cells and T cells and their secretions 。Inflammation ·Antibodies Normal microbiota ·Fever Antimicrobial substances Figure 16.1 Host Defenses Figure 16.1