Overview: Dr Chris and Dr Xand reveal how your bones grow to make you taller, while in Operation Takeover they take on the role of midwives for the day. Plus Dr Chris investigates how scientists are studying people in low oxygen conditions to help seriously ill patients, and we catch up with Ouch Patients Kaden and Maisie. Meanwhile in accident and emergency, one patient has cut their head falling off a wall and another needs help fishing a pencil out of his ear.