Dr Chris and Dr Xand reveal the surprising secret behind the speed of your nerves, and Dr Xand finds out what happens if you don't wash your hands.
This week Dr Chris and Dr Xand are looking at blood; what's in it, and where does it come from?
The Doctors reveal what happens when you get diarrhoea, Dr Xand gets his skates on when he meets Alexia and Kloe from CBBC's 'Ice Stars' to investigate how they spin without getting dizzy, and there's a hidden camera experiment in 'Mind-Benders'. Meanwhile the 'Ouch Mobile' is open for more medical mysteries, and in Accident & Emergency one patient needs surgery for a broken arm, and another gets help with a painful toe
The doctors reveal how kidneys work, while in A&E one patient has an unusual leg injury and another has a stone stuck in his ear
The Doctors find out what happens when you eat with the help of a miniature Xand doll, test your ears and eyes in a baffling mind-bending trick, and join Dr Chris at work fighting infectious diseases. Meanwhile there's an unusual 'itis' in the 'Ouch-Mobile', and over in Accident & Emergency one patient has cut their head and another has a very wonky finger
The Doctors reveal the amazing organs that keep you alive before you're born, Dr Xand meets patients undergoing treatment at a burns clinic, and Dr Chris hits the high street to test another mind-bending trick. Meanwhile, there are more medical mysteries in 'Ouch & About' and over in Accident & Emergency one patient has broken her ankle, and another has been hit on the head with a cricket bat
Chris and Xand choose their favourite moments from the series, including an experiment to find out what happens when someone coughs.
Dr Chris and Dr Xand take a look at what happens to your body during puberty and why.