How does acute inflammation differ from chronic inflammation?
Acute Inflammation Acute inflammation is a normal process that protects and heals the body following physical injury or infection. Acute inflammation involves local dilation of blood vessels as well as increased vessel permeability to improve blood flow to the injured area. At the site of an infection or injury, mast cells, platelets, nerve endings, endothelial cells, and other resident cells release signaling molecules and chemoattractants that recruit leukocytes to the affected area. Neutrophils, a type of granulocyte, are the first leukocytes to appear at the injured site. These cells phagocytose (engulf) and kill invading microorganisms through the release of non-specific toxins, such as superoxide radicals, hypochlorite, and hydroxyl radicals; these reactive oxygen species (ROS) kill pathogens as well as adjacent cells, sick and healthy alike. Neutrophils also release cytokines, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-alpha, gamma interferon (INF-gamma), an
