Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. To finish this series, they're in the brain getting acquainted with the amygdala.

Is the amygdala really the home of fear? Kimberley and Xand meet someone who has had theirs removed, discovering the true nature of this part of the brain, and how it can give us a roadmap to dealing with our everyday anxieties.

Producer: Georgia Mills

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. This time, they examine the wrist, and its role as the hub where technology meets the body.

Kimberley and Xand meet a man whose life was saved by his smartwatch, examine the potential pitfalls of devices that don't work for everyone equally, and learn how much data our wrists can truly give away.

Producer: Georgia Mills

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. This time, the ovaries go under the microscope.

Kimberley and Xand hear from someone whose ovaries have caused them to hurtle through major life stages in the course of a few years, meet a scientist who thinks we may have female fertility all wrong, and examine the unresolved mysteries of the menopause.

Producer: Georgia Mills

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about how we live in the world. In this episode, they find out there's much more to tears than meets the eye.

What is the purpose of tears, does crying actually make you feel better, and what happens when you lose your ability to make them at all?

Producer: Georgia Mills

A Whistledown production for BBC Radio 4

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. In this episode, they take on the social media pariah - dopamine.

They examine this tiny chemical's wide roles in the brain and body, and question whether we should make cognitive enhancers available for general use. There's also a dive into some intriguing research which suggests your breakfast could influence your most fundamental decision-making ability.

Producer: Georgia Mills

A Whistledown production for BBC Radio 4

Psychologist Kimberley Wilson and Dr Xand van Tulleken continue their journey around the human body, asking what our insides can reveal about our lives and the world around us.

The knee is one of the most complicated joints in the human body, but also one of the most prone to failure. In this episode, Kimberly shares the story of someone with a rare genetic disorder that results in poorly developed kneecaps, while drilling into the gory detail of knee replacements. Later, Xand explores osteoarthritis and the exciting research that could change how we think about joint injury.

Producer: James Tindale

Psychologist Kimberley Wilson and Dr Xand van Tulleken continue their journey around the human body, asking what our insides can reveal about our lives and the world around us.

This week, it's Sphincters' turn. While the one in our bottoms tends to claim the most mindshare, we’re absolutely full of sphincters, and they’re critical to our lives.

In this episode, Xand explores the inability to burp, meeting a 27-year-old who was unable to belch until an American Doctor’s revolutionary procedure changed his life forever. Meanwhile, Kimberly investigates urinary sphincter failure and the innovative implants that can help restore continence.

Producer: James Tindale

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. In this episode, Kimberley and Xand are looking at our kidneys, and the enormous societal problems caused by this fist-sized organ.

Together they bust some detoxing myths, hear about the dangers of the billion dollar illegal organ trade, and whether an artificial kidney might be on the way.

Also - how many glasses of water do we really need in a day?

Producer: Georgia Mills

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, to find out what it can tell us about our innate capacity for change. In this episode, Kimberley and Xand head up the rebranding of an organ with terrible PR - fat.

They hear why fat is intrinsically linked with being human, how it's doing a lot more for us than just sitting there, and why having a bit more fat can help us take the plunge.

Producer: Georgia Mills

Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, asking what it can tell us about ourselves and the world around us. In this episode, Kimberley and Xand get to the root of our hair problems.

From the race to grow hair in a dish, to the vast inequalities that have resulted in permanent hair loss, Xand and Kimberley explore the enormous significance we impart on a string of dead cells on our heads.

Producer: Georgia Mills