How does your immune system work

Explore how your immune system’s vast network of cells, tissues, and organs coordinate your body’s defenses against bacteria, viruses and toxins. -- The immune system is a vast network of cells, tissues, and organs that coordinate your body’s defenses against any threats to your health. Without it, you’d be exposed to billions of bacteria, viruses, and toxins that could make something as minor as a paper cut or a seasonal cold fatal. So how does it work? Emma Bryce takes you inside the body to find out.