If a pathogen manages to penetrate the body, further innate defensive mechanisms await: bactericidal enzymes, inflammation, and phagocytosis.
Mast cells are remarkably similar to basophils, which are a type of white blood cell. While mast cells play their role in innate immunity, white blood cells are a primary agent in acquired immunity.
Mast cells reside in tissues surrounding blood vessels and nerves and are particularly prominent near the boundaries between the world outside and the body within: the skin, mouth, nose, eyes, lungs, and digestive tract.
Mast cells are a key actor in inflammation, promoting wound healing and pathogen defense. Mast cells carry an arsenal of bioactive chemicals to assist healing. Mast cells also mediate allergic reaction.