Editing Immunology (section)

=== Cellular Responses and Inflammation ===
If a pathogen breaches these barriers, innate immune cells deploy to the site of infection. 
* '''Phagocytes:''' Cells such as macrophages and neutrophils patrol tissues. They recognize broad molecular patterns common to many pathogens (Pathogen-Associated Molecular Patterns, or PAMPs) using specialized surface receptors. Once bound, they engulf and digest the microbe through a process called phagocytosis.
* '''Inflammation:''' Injured cells and local immune cells release chemical signals like histamine, causing local blood vessels to dilate and become permeable. This brings a rush of blood, fluid, and additional white blood cells to the area, resulting in the characteristic heat, redness, swelling, and pain of inflammation.