Lines Of Defense In The Immune System
In a healthy body, the immune system utilizes 3 lines of defence for protecting the body.
The first line of defence consists of non-specific, predominantly physical defences; such as intact skin, mucus and ear wax, cilia, acidic environments, salty environments and urine flow. Should the threat pass the first line of defence, the second line of defence will be the next challenge for the pathogen to face. The second line of defence, while still more of a blanket defence, is much more cellular inclined than the predominantly physical first line of defence. The second line of defence uses Phagocytes to consume and destroy pathogens, fevers to denature pathogens, transferrins to starve pathogens, Dendritic cells to spot pathogens and Natural killer cells to blast the pathogen with deadly chemicals. If the first two lines of defence fail, that means two things: 1, this pathogen is hard as nails. And 2, its time to bring out the bug guns. The third line of defence is the last line of defence. It uses a team of cells to kill the pathogen; the team of b cells scour the body for specific antigens, while T cells search for appropriate MHC markers to target. Should the third line fail, the body will die unless there is a medicine that can specifically take out the pathogen. If there isn’t, then its curtains. |