Nate is learning about human body systems, and in this episode he finds out about how important the immune system is. The leucocyte army explains that bacteria, viruses, fungi, and parasites can pose a threat. The nose serves as the location of first defense, where invaders are identified,and the immune system is activated. Consider assigning this as homework for a flipped classroom approach to your health or biology curriculum. For extra health-focused enrichment, consider the additional resources available through links on the "Your Immune System" article webpage.