The three major functions of the immune system are: defending the body against invaders, destroying those invaders once inside, and limiting the harm caused by invaders.
Here's a more detailed breakdown:
- Defense Against Invaders: The immune system acts as a barrier, preventing harmful pathogens (bacteria, viruses, fungi, parasites) from entering the body. This includes physical barriers like skin and mucous membranes, as well as chemical barriers such as enzymes in tears and saliva.
- Destruction of Invaders: If invaders breach the initial defenses, the immune system actively works to eliminate them. This involves a complex network of cells (e.g., macrophages, T cells, B cells) and molecules (e.g., antibodies, cytokines) that identify, target, and destroy pathogens.
- Limiting Harm: Even when the immune system successfully destroys invaders, the process can cause damage to the body's own tissues. Therefore, a crucial function is to regulate the immune response to minimize this collateral damage and promote healing. This involves mechanisms to dampen inflammation and repair damaged tissues.
In simpler terms, the immune system functions like this:
- Keeping Out: Preventing germs from getting into your body.
- Killing: Destroying germs that do get in.
- Coping: Limiting the damage germs can cause and helping you heal.
These functions are essential for maintaining health and protecting us from disease.
