Part 2/14:
Huberman begins with a simplified yet comprehensive overview of the immune system, emphasizing its elegance and efficiency. The body's primary defense is a physical barrier—the skin—which acts as the frontline shield against potential invaders. Breaches, such as cuts, temporarily compromise this boundary, introducing vulnerability.
Beyond the skin, openings like the eyes, ears, nostrils, and mouth serve as critical entry points for pathogens. These open portals are lined with mucus, which acts as a biological filter—trapping bacteria and viruses and even possessing mechanisms to neutralize or destroy these invaders. The respiratory and digestive tracts are similarly equipped with mucus linings, which are crucial to preventing infection.