This video gives an overview of the immune system of our bodies including the topics of barrier immunity, innate immunity, adaptive immunity and the contrast between innate and adaptive immune systems. Timeline: 0:00 - Introduction and objectives 0:56 - Introduction to immune system and its basic structure 2:13 - Barrier Immunity 5:00 - Innate Immunity 15:03 - Complement system 16:25 - Adaptive Immunity 22:13 - Innate vs adaptive immunity