The CVM anatomy lab is chocked full of models, including full-sized llama and horse skeletons, several cow rumen, and, of course, a stuffed beaver in an orange bandana. Many of the models were constructed by students.
This year, some of the models assigned by Dr. Fikru Nigussie, Associate Professor of anatomy, were a bit different; they required movable parts and paint.
Dr. Nigussie is creating a display of the limbs of many different animals, so students Ben Ulrich and Laura Macintyre constructed dog, cat and cougar limb skeletons, then painted each bone a different color and labeled it with a number.
“Carpal and tarsal bones are really complicated and can vary between species,” says Ulrich. “Dr. Nigussie wanted a comparative limb display where you can look across the species, and the colors correlate to specific bones. The beetles are still working on horse, cow, sheep and goat limbs.”
Beetles?
Many of the skeletons that students assemble for use in the anatomy lab arrive as loose pieces in a box ordered from a supplier, but the limbs for the new comparative display arrived as meat. Rachael Cunningham took on the task of turning them into clean bones.
“We set up a colony of beetles in a wooden box, with a grate at the bottom where the bedding is; that’s where they live and hang out,” she says. “It seals tightly, and has a filter and fan at one end. Beetles are pretty particular about the temp they live in; you have to keep them cool in the summer, and warm in the winter, in order to keep them alive.”
Once Cunningham placed a leg in the box, it took about three weeks for the bugs to strip it. “Before I put the specimens in with the beetles, I would dissect off as much tissue as I could,” says Cunningham. “But there is still a lot of stuff around the joint, and really close to the bone, that is very difficult to remove. The beetle’s job was to clean up everything I couldn’t get off.” When the beetles are done, the bones come out of the box looking dirty, so Cunningham’s last step was to soak the bones in hydrogen peroxide to make them white.
Once the cat limb bones were ready for Macintyre to assemble, she had to figure out how to attach them. “I read through the assembly manual,” she says “but I was trying to incorporate the use of magnets. I wanted something that people could take apart for a closer look. Dr. Nigussie knew somebody at the University of Washington who had used magnets, so I called and asked him for advice.”
Then Macintyre had to pinpoint exactly where each muscle attaches to the bone and mark it. “I had to go back and review the PowerPoints [from first year anatomy class],” she says. “None of us had experience doing this, and it was pretty hard. There was a lot of trial and error,” she says. “But now I have a really solid idea of where everything is.”
Ulrich faced similar challenges on his assignment to build a dog skeleton. “It came as a box of bones,” he said. “Everything was already articulated, which should have made it easy, but I had to break down a lot of the joints, because Dr. Nigussie wanted half of the body to have movable joints.” Ulrich had to figure that on his own. “They didn’t give me directions,” he says, “so I had to use trial and error.” He tested out a few ideas; rubber bands definitely didn’t work. “I realized they would dry out and deteriorate, and I needed something that would last.” He ended up in a store that doesn’t normally supply anatomy labs: JoAnn Fabric. “I finally went there and got elastic bands.”
Jackie Houser also tackled a full skeleton, a ferret, and her biggest challenge was size. “All the pieces are really tiny, and my fingers are pretty fat,” she said. “The little ribs are very fragile and one of them actually broke in half, so I had to repair that before I could glue it to the spine.” She also struggled with getting all those ribs attached perfectly parallel. “The ribs were the hardest part of the whole skeleton,” she said. “I’m kind of a perfectionist and it still bothers me that the ribs aren’t perfectly laid out.”
All the students building models this summer needed persistence and problem-solving skills. They also relied on their class notes. “For some things, especially the dissection, what I started doing didn’t work so well. I found that it helped a lot when I went back and reviewed my anatomy, then changed my strategy based on that.”
Ulrich adds: “I finally figured out a good strategy for putting things together on my last project. So if students need advice next summer, I can help.”