Tackling the serious topic of stress in his famously entertaining manner, Professor Sapolsky sets the stage on a Kenyan savannah, with a hungry lion in hot pursuit of a terrified zebra. As he explains, the zebra's fight-or-flight response channels essential energy to its survival effort by shutting down and even damaging nonessential biological functions- in a temporary, short-term response. Unfortunately, humans can generate the same response simply...

The development of a child from conception to birth, using both microimagery and the story of a young couple preparing for their first child.

The course concludes with an exploration of other potentially addictive behaviors. Professor Polk argues that some artificial stimuli - junk food, pornography, and video games to name three - are "supernormal," meaning that they actually activate the brain's reward circuit more strongly than natural stimuli do, leading to some of the same neurological effects as drug use.

Caffeine and nicotine are two of the most common psychoactive drugs in our society. How do they work? How dangerous are they? After reviewing how each of these drugs affects the brain - and why nicotine in particular is so addictive - Professor Polk offers several strategies to quit tobacco use.

Take a deep-dive into the universe that's inside each one of us, by exploring shared biology that people often don't take the time to appreciate, or understand. Heart, brain, eyes, blood, tears; uncover not only the science behind how the bodies work but how what's inside powers every moment of what is done out in the world. Personal profiles of people from around the globe become entry points into deeper stories about how the body's many systems...