Questions around the effectiveness of using cat cadavers led this instructor to try a series of experiments. This is how she got from Point A to 3-D.
Lecturer in Anatomy and Physiology, The Sage Colleges, Troy, NY
PhD and MS in Biological Sciences, BS in Biomedical Engineering
Erin Harmon likes figuring out how things work. It shows in her background: Before earning a PhD in biological sciences, Harmon was a biomedical engineer. It also shows in the ideas she brings to her classrooms today as a lecturer in anatomy and physiology at The Sage Colleges in Troy, New York.
“I like creating and inventing things,” Harmon says, gesturing to the 3-D model that takes up a third of her desktop. Comprised of parallel foam discs, the model is one that Harmon helped create to illustrate sliding filament theory for her Human Biology students. The sliding discs represent a model of a sarcomere—a small section of striated muscle whose individual, overlapping filaments slide over one another when muscles contract and relax.
“It helps explain how muscles work,” Harmon says. But the truth is that it does much more than that. It highlights the creative, engineering mind that helped solve an ongoing problem in an anatomy and physiology class and helped students learn about muscle origins and insertions in a new formaldehyde-free format.
Challenge: Cat anatomy is not human anatomy
Cat dissection has long been used in anatomy and physiology courses as a way to teach basic structures, as well as to highlight important concepts such as how and where muscles attach to bone and how muscles create movement.
“A key part [of anatomy] is knowing what each muscle does,” Harmon explains. “You see how a muscle pulls on a bone, how that creates movement. How it creates flexion or extension of your elbow, for example—if it pulls from the front or the back, that will result in different movements.”
Seeing the real structure firsthand is a time-tested way to understand muscle function, but, over time, Harmon and her colleagues wondered whether the cat cadavers were really teaching students what they needed to know.
“There are a lot of similarities between cat muscles and human muscles, and cat bones and human bones, but it’s not identical. If our goal is to get students to learn human anatomy, cats might not be the right choice,” says Harmon. “I saw that [students] were getting really good at learning cat anatomy and not transitioning that over to human anatomy as well as [I would have liked].”
Add in that some students found it emotionally challenging to dissect cats—they were not thrilled by the idea of dissecting what many considered to be pets—and Harmon figured it was time to change. So she developed a new model, both figuratively and literally.
Innovation: Focusing on hands-on creative solutions
After a few semesters of using cat dissections as the primary way in which skeletal muscle anatomy was taught, Harmon stopped using cats altogether. However, she needed to find a new way to bring the material to life in a hands-on way, without the use of the cadavers.
After many failed experiments, Harmon uncovered a solution that she thought would work: a 3-D printing pen called the 3Doodler.
A 3-D printing pen works like a glue gun but is shaped (and held) like a pen. “Instead of glue coming out, it’s a plastic that hardens,” Harmon says. “So you can draw straight up into the air and, as long as you go slowly enough for the plastic to reharden, the structure can stand.”
“The pens are designed for artistic purposes,” Harmon continues. “I had never seen them used for this application.” But she thought it was worth a try.
And it is the manner in which she happened upon this multidimensional solution that is the heart of this story.
“One thing I like is how small my labs are. I get to work with [students] on an individual basis. I love that lightbulb moment when they figure something out. A lot of them come in thinking that science is hard, and it’s great to see them be successful. I like making them feel like they can do it.”— Erin Harmon, PhD
Course: BIO 201 Anatomy and Physiology I
Frequency: Two 80-minute lectures and one 3-hour lab per week
Class size: 32 students (16 per lab)
Course description: First term: Students will investigate the structure and function of the cell, the skeletal and neuromuscular systems, and the proprioceptive and reticular activating systems relative to sensation, perception, and movement. Second term: Studies of the blood, circulatory, digestive, and urinary systems will be included. Laboratory work will include experiments on animals and animal tissue and exercises with human subjects.
See Erin Harmon's teaching resources for BIO 201 Anatomy and Physiology ISee materials
Lesson: A bare-bones plan for innovating in the classroom
The disconnect between cat and human anatomy is what first led Harmon to explore creative alternatives for her class, but her dedication to hands-on learning is what led to her innovation.
Here are the practices that helped her ensure that the new direction would suit her students’ needs—academically and emotionally.
Know your primary goal (and stay focused on it)
The BIO 201 course at The Sage Colleges is about human muscles and human anatomy; the cats had always been a means to an end. By staying focused on that primary goal, Harmon was able to develop a new practice that she has found to be an improvement on cat dissection.
Try new things, but watch for weaknesses
Harmon approached the problem in many different ways before arriving at the 3-D pens. “There was a transition period after we had stopped using the cats, and [the students] were using tables, memorizing origins and insertions, looking at pictures,” Harmon explains. “It wasn’t very exciting. Then I printed out paper skeletons and had students draw the muscles on a 2-D skeleton, but the problem there was that some muscles attach in front and back, or along the side. So it worked for some muscles but not others.”
Ask others for ideas
As she pursued a new solution, Harmon spoke with colleagues about the challenges she was facing. During one such conversation, she heard about an instructor who was using colored tape to mark origin and insertion points of muscles. That thought popped back into her mind when she saw the various colors of plastic available for the 3-D pen.
Keep learning styles in mind
Harmon saw that when her students would memorize the origin and insertion points using a table, this did not help them visualize how the various parts and muscles fit together. “Visualization is key,” she says. “Going from 2-D to 3-D allows them to connect the actions of the muscles to the attachment sites so much better. Before, they weren’t thinking about how the muscles cause movement [and] how that is related to where they attach. Now they memorize less and can visualize how everything fits together.”
Never stop making things better
Harmon kept experimenting with different ways to get her students to visualize human anatomy, eventually landing on the idea of using 3-D printing pens to draw muscles and tendons on plastic (half-size) skeletons to demonstrate their points of attachment. The skeletons can be reused—Harmon says the plastic from the 3-D pens is easily removed.
Both products were purchased online; she currently has one pen for every two students in the lab.
Always maintain your level of rigor
Doing away with cat cadavers was not about making class easier for students—it was about making them more successful. Harmon did not adjust her expectations of students when her initial replacements were not working. Instead, she expected more of herself.
“My classes are pretty rigorous, and I value keeping it that way,” says Harmon. “Science classes are challenging by their nature. I don’t want to dumb anything down, but I do want to make it easier for [my students] to be successful. For me, it’s not about getting the A, it’s about putting in the effort. I am so proud of so many of my C students, because I know they are doing their best.”
Harmon has found that the new approach helps students understand human anatomy rather than cat anatomy.
“The 3-D drawing allows them to connect the actions of the muscles to the attachment sites so much better than memorizing bits of information,” Harmon says. “And visualization is key. Now students are thinking even more about how the muscles cause movement, how that is related based on where they attach. Now they memorize less and can visualize how everything fits together.”
“My hope is that the approach helps with long-term retention,” she continues. “Since they [are] physically drawing the muscle, it should stay in their memory when they go to recall it.”
Here are some quotes from recent student evaluations of the course:
“The pens we used to draw the muscles during that lab were very helpful! It helped with knowing where the muscles originate and where they connect on other parts of the body. It was a very creative, enjoyable lab and I still utilize the information of where each muscle was drawn on the skeleton a year later in other classes! I believe this lab helped with understanding muscle movement and location and is very useful to students as myself in the Physical Therapy tract!”
“The most memorable lab from last year was this lab because it was hands on and a lot of fun to use those pens! Also, the muscles that I personally drew were the ones that I knew the best, and still know to this day (I can’t tell you why but I’ll never forget the sternocleidomastoid muscle!).”
“The muscle drawing lab really helped in visualizing each muscle and where it connects. I definitely was able to understand where each muscle connects by using the 3-D pen and drawing on the muscles by myself. This really helped me in preparing for the lab quiz as well.”
“The 3Doodler pens not only help students learn the structure and shape of the muscles but they also allow the students to review the importance of the bony structures in the body.”