Final answer:
Innate immunity involves the secretion of mucus, lysozyme, and immune factors such as intestinal gastrin, as well as antibodies IgA and IgM from activated B cells to combat pathogens.
Step-by-step explanation:
Innate immunity features several types of secretions that play a crucial role in the body's first line of defense against pathogens. The secretion of mucus, which acts as a physical barrier, traps microbes and contains immunoglobulins like IgA that can neutralize pathogens. Another important secretion is the bactericidal enzyme lysozyme, found in tears and saliva, which has the capacity to break down bacterial cell walls, contributing to phagocytosis. Additionally, the gastrointestinal tract secretes immune factors like the hormone gastrin, which stimulates the secretion of gastric acid and serves to decrease the pH in the stomach, thus inhibiting the growth of many bacteria.
Within the mucosal immune system, activated B cells differentiate into plasma cells, which then synthesize and secrete the antibodies IgA and IgM. IgA is abundant in tears, saliva, breast milk, and in secretions of the gastrointestinal and respiratory tracts. The main function of these antibodies is to prevent infection of the mucosa by binding to and neutralizing pathogens, a process that is enhanced by vaccinations targeting diseases like influenza.