Student Achievement Comparisons
A study that surveyed Ontario science teachers on their beliefs about animal dissection found that over half of teachers indicate that they use dissection for pedagogic reasons; that dissection helps solidify student’s knowledge and reinforce concepts; and that it is the “best” way to learn about anatomy and physiology (Oakley, 2012). However, many studies have demonstrated that non-animal alternatives can also provide effective educational learning opportunities. Alternatives can typically be used multiple times, are cost effective, align with the 3Rs, and do not harm animals.

Graph from Society for Humane Science
In a 2022 article in The American Biology Teacher, researchers conducted a systematic review of studies published between 2005 and 2020 that evaluated the pedagogical value of non-animal models versus animal dissection. They found that non-animal alternatives performed as well as, or better than, dissection in 95% of the studies.
Alternatives
There are numerous alternative resources for teaching about body systems that continue to be improved upon.
Here are a few: human anatomy links, online dissection simulators, apps and other alternatives.
References:
Oakley, J. (2012) Science teachers and the dissection debate: Perspectives on animal dissection and alternatives. International Journal of Environmental & Science Education Vol 21(4). pp. 360-267. PDF