Nervous, curious, worried, excited—these were some of things 7th grade students were feeling before their first dissection of cows’ hearts earlier this year. Now, four dissections later, they are pros. One student commented, “Dissections are really interesting, creepy, and full of information.”
The dissections were part of a unit on anatomy, which builds on the 4th grade introduction to human systems. When the 7th graders revisited the circulatory/cardiovascular, nervous, digestive, and reproductive systems, they already had a baseline understanding of the various systems and were ready to study them in more detail. Students also learned how these systems work together. For their test they had to be able to answer questions like How does the small intestine (digestive system) play a role in the circulatory system? After dissecting the cows’ hearts, students tackled cows’ eyes and sheep’s brains, and these hands-on opportunities in the lab enriched and informed their classroom studies.
The final dissection of frogs (pictured at right) was a study in comparative anatomy, and it was the first time students were able to see how all the systems function together. There was much to investigate and some students were surprised by what they found, including eggs and the remains of the frogs’ last meals. Students were also challenged to locate the brain and spinal cord, which are small and hard to find. Several enthusiastic students were even able to identify the left and right hemispheres of the brain.
Every student in the 7th grade decided to participate in the dissections, although they were given the option of participating in a virtual dissection or completing an alternate project. In the end, students said that they learned things during the dissections that they couldn’t have learned from a book (for example, how heavy a cow’s heart feels). While enthusiasm for doing more dissections in future science classes was not unanimous, at least one student decided that she might just be “a dissection type of person.”