How your body's internal patrols identify and destroy invading pathogens

Science · Published 23 October 2026 Swipe more like this →

In short: Explore the complex layers of human defence, from the physical barriers of your skin to the specialized white blood cells that patrol your bloodstream to hunt foreign substances.

This video breaks down the distinction between our first line of defence—physical and chemical barriers like skin, mucus, and stomach acid—and the active immune system. It examines how the body responds once pathogens bypass these barriers.

You will learn the specific roles of white blood cells, specifically how they use phagocytosis to engulf pathogens and how they produce antibodies to target specific antigens. The session also covers how immune memory and antibody specificity contribute to long-term immunity.

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