In the dissection lab on the third floor of The Anlyan Center, first-year student Rachel Nelson guides a small group of her classmates through the anatomy of the shoulder. Nelson’s gloved hands point out muscles and nerves, and some students move their arms to mimic the motions these muscles were made to make. This is a peer teaching session, an educational innovation added to Yale’s gross anatomy course this year. Half of the 104 students in the class dissect their donors’ arms and shoulders, while the others master the hips and legs. An hour later, the groups switch—those who studied the upper limb teach those who had studied the lower limb. Each student needs to teach, and each needs to be taught.

“I enjoy peer teaching,” says Nelson. “It can be valuable to solidify information. When I am teaching others, I hold myself even more accountable for being on top of the information and presenting it accurately.”

As the students work, William B. Stewart, Ph.D., who leads the course with Lawrence J. Rizzolo, Ph.D., stands back, looking on. “I try to observe rather than participate,” says Stewart, associate professor of surgery (gross anatomy), but it is clear that after 38 years of teaching anatomy, he would like to “get in there” and examine along with the students. Instead, he walks from group to group, listening.

“The Latin root of the word ‘doctor’ is ‘teacher,’ ” Stewart says. As physicians, students will be teaching for the rest of their lives; they will teach their colleagues as well as their patients. “It’s a lifelong commitment. Teaching is a skill that has to be practiced. There are no natural-born teachers.”

Formalized peer teaching is a core aspect of the redesigned gross anatomy course, launched as part of the medical school’s curriculum rebuild in the 2015-2016 academic year. The new curriculum has gross anatomy, traditionally taught in the first semester of the first year, beginning in January of the first year and running through December of the second year. It has also been reduced from approximately 110 hours to 75 hours. Fifteen hours were cut entirely, Rizzolo said, while the remaining hours were redistributed to such courses as radiology or pathophysiology, in which there has been an overlap of material.

As with the new curriculum, emphasis has shifted from the classroom to the clinic. “Our philosophy has always been to make the lab as much like the clinic as possible, and as little like college as possible,” says Rizzolo, professor of surgery (gross anatomy) and director of medical studies.

Rizzolo watches as students grapple with the intricacies of the brachial plexus, drawing on a chalkboard a diagram of the complex system of nerves that runs through the neck and shoulder. He sees a mistake—what they are sketching is not reflected in the donor, but he holds off. In the peer teaching process, “there’s a real desire to jump in and fix it, when the best way is to allow students to discover and correct their mistakes,” he notes. “Mistakes are teaching opportunities. Celebrate them. In the anatomy lab, we make all the mistakes we want. And then the knowledge gained will stick.”