The inflammatory response and cell migration.

If a pathogen has successfully invaded a tissue, the macrophages in the tissue may recognise the pathogens with one of the receptors and attempt to phagocytose and kill the pathogens. Often there are not enough macrophages present in a tissue to phagocytose and remove all the pathogens and therefore the tissue macrophages initiate a response that will bring additional phagocytes, together with a variety of proteins, to the site of infection from the blood. These cells and proteins then help to remove the pathogen. This response is known as the inflammatory response. The aim of the inflammatory response is to recruit cells and other factors from the bloodstream into tissues to aid in the remove of pathogens and dead cells or tissue. Leukocytes (white blood cells) are unique in their ability to move throughout the body. They travel through the bloodstream and also have the ability to leave the bloodstream and enter tissue or organs. This ability to move around the body is also referred to as ‘cell migration’.