Our most vital part of the human body is the immune system, responsible for protecting against infections and foreign invaders; exacly like a castle and the immune system is the army protecting the castle.
The first line of defence, is for the immune system to prevent the invaders, entering the castle. This is done through the use of physical and chemical barriers. The castle is protected by the skin and mucous membranes. to keep the castle healthy you need to exercise, food and relaxing time
