Inside the human body. Part 4, Hostile world.

The last in a four-part series, presented by Michael Mosley, in which CGI footage is used to show the workings of the human body. In this part, Mosley looks at the way the body defends itself against accidents and illnesses. Focusing in microscopically on the world of the phagocyte, the CGI animation shows how phagocytes undertake battles to defend the body from invaders. We meet 99-year-old Esther Tuttle from new York and study the fast reflexes of the Cardiff Devils ice hockey team. Bull jumping champion, Christian Serra has developed incredibly strong leg muscles which allow him to bounce from the ground and Johnny Greaves is a professional lifht welterweight boxer who has taken so many knocks, it's hard to see how his body repairs itself continually. Three-year-old Rowan fights the flu and Richard Edwards survives a double hand transplant - Richard's journey before, during and after the surgery is shown.