Immune System, Part 2: Crash Course Anatomy & Physiology #46

In the penultimate episode of Crash Course Anatomy & Physiology, Hank explains your adaptive immune system. The adaptive immune system’s humoral response guards extracellular terrain against pathogens. Hank also explains B cells, antibodies, and how vaccines work. Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: Download it here for Android Devices: Chapters: Introduction: Adaptive Immune Responses 00:00 How B Cells Identify Antigens 2:14 B Cells Become Effector Cells & Memory Cells 4:05 How Antibodies Fight Antigens 5:22 Active and Passive Humoral Immunity 6:03 How Vaccines Work 6:27 Review 8:30 *** Crash Course is on Patreon! You can support us directly by signing up at Thanks to the following Patrons for their generous monthly contrib