The third episode looks at anxiety and explores why it is so common. It talks to neuroscientists who explain the physiological and evolutionary basis of anxiety. Although it can help animals escape predators, anxiety can cause serious problems for human beings. It talks to sufferers of anxiety and examines the different types of anxiety people can feel. It also looks at how social media can cause anxiety.

The final episode of this series looks at what happens to the brain when someone uses psychedelic drugs. It looks at how psychedelic drugs may be useful in dealing with anxiety in cancer survivors and serious depression. It explores the history of psychedelics and examines early medical experimentation with the drug. It also discussed why psychedelics were banned and examines how they affect the brain.

What's behind a pulse? The second episode dives into the world of an ice climber, a bus driver, a woman in labor, and a senior dance club to show how the human heart and the circulatory system power our physical and emotional lives, and create the pulsing rhythm of our world.

The episode is a journey through the human gut and the process of turning food into energy to keep the body going. Humans have turned eating into culture, a way to celebrate our roots, to bring us together. But food is really just one thing: Fuel. It's where you get the power to live your life. Even when you're sitting completely still, your body needs a lot of energy to stay on. But nowhere is the need for fuel more apparent than when you push yourself to the absolute limit. And the microbiome, the bacteria living in our gut, plays a great role in all this.

A look into how the body defends itself against all odds through the stories of a nature survivalist, rancher twins, a doctor who survived Ebola and a cancer therapy recipient. The Immune System, essential to our survival every second, is the most complex and least understood piece of our biology.

How do the five senses really work? In fact, there are many more than five, and they all work together to create our own version of reality. We dive into the stories of a pairs figure skating team, a perfumer, a cave explorer, and a musician to decipher how different ways of sensing the world all create their own vivid, and unique, picture.
This episode explores the world of human sensation and how it defines reality.