Something that you might not realize about your immune system is that it’s actually made up of two distinct categories, each with their own functions and their own purposes. These two categories are known as innate immunity and adaptive immunity, and they’re both very important to preventing and fighting diseases in your body. Understanding them is key to realizing how exactly your body fights off disease.
Innate immunity is your absolute first line of defense. It prevents diseases by making their way into your body in the first place and doesn’t really go after anything in particular. It’s often described as being “non-specific,” because it fights off anything that it finds that shouldn’t be there, instead of going after a specific virus or bacteria. Part of your innate immunity that you see all the time is your hair and skin. Your skin of course acts as a barrier between the outside world and the rest of your body, keeping anything that wants to get in out. Your hair helps trap various forms of microorganisms, so you should wash it regularly to consistently keep it clean. This is also why you shouldn’t bite or chew your hair if you have long hair, because it is very much there to keep things out of your body. Your innate immune system also consists of many internal components, such as mucus.
Mucus provides a very similar function to hair, by trapping microorganisms. Mucus traps these bacteria and diseases before they can make it down into your respiratory system, which is why you develop a cough as you start to get sick. There are also many cells that will attack anything they find in your body to be out of place. The adaptive immune system is fairly different, because it responds when a threat has been found and is starting to become a problem. This part of the immune system typically specializes in taking out the illness in various ways, whether it be opening up the membrane or carting it off to be flushed out of the system.
Your T and B cells are the most common examples of the adaptive immune system. These cells retain memories, in a way, of viruses and bacteria that they’ve fought before, so that they know how to fight them again. When a threat is detected, they go to identify it and then take the proper course of action that they need in order to get rid of it.