If you’re training to become a physician, your first patient is usually dead. In fact, “first patient” is what med students call the human cadavers that they work on in anatomy class — when they first learn to make careful incisions, and lay eyes on the beautiful intricacies of bone, muscle, blood vessels, and organs that make our bodies work.

Human cadavers have long played a crucial role in medicine and science. They not only teach generations of doctors about the human body — they allow researchers to learn valuable lessons about everything from the causes of rare diseases to the effects of how we live our lives. But how do bodies end up on dissection tables in the first place? What can they still teach us? And why do people choose to donate their remains?

On this episode, we explore bodies donated to science — how they’re used, why they’re so important, and why people make this choice for their remains. We hear stories about one woman’s mission to recruit future medical cadavers, and how 19th century medical schools got involved in body snatching. We’ll take a closer look at a program that connects med students to the families of their “first patients,” and find out why one firefighter has opted for a future in the Body Worlds exhibition.

Also heard on this week’s episode: