Your body has evolved an exquisite immune system to take down any threat it encounters. This system is made of up two arms:
Innate immunity: like a town’s police force:
- It responds to all threats regardless of their type (non-specific).
- When it finds a threat, it immediately responds with all its might to eliminate it.
- It retains no memory of the intruder after it is cleared up.
- Is found in nearly all life forms.
The innate immunity is composed of much more than just white blood cells. Your skin is also part of this defence system. It acts as both a physical barrier and a chemical one by secreting antimicrobial proteins. Tears, saliva, and breast milk also all contain proteins to fight off infections. There are also proteins in your blood that act to poke holes in foreign cells called the compliment system.
Adaptive immunity: like the special operative forces:
- It attacks specific intruders that it has been educated against.
- There is a small time lag between exposure to the threat and maximal response.
- It retains a memory of the fight so that it can more quickly eliminate it in the future.
- Is found only in animals with a jaw.
The adaptive immune system is specialized. It is made up of lymphocytes that make antibodies and recognize specific threats. Vaccines educate your adaptive immune system so they can respond more quickly to the next threat.
These two systems never work alone, they are always communicating with each other to help keep you safe. Defects in the functioning of these two systems can cause a variety of diseases. Autoimmune disorders are problems with the adaptive immunity. Inflammatory disorders are problems with the innate immunity, often caused by problems turning off inflammation.
Header Image: “Neutrophil with anthrax copy” by Volker Brinkmann