What discoveries about the human anatomy have been made during animal testing?

Animal testing has contributed significantly to our understanding of human anatomy, particularly in areas like cardiovascular function, neurobiology, and organ systems. For instance, studies on rodents have revealed insights into the human nervous system's structure and function, helping to identify mechanisms underlying diseases like Alzheimer's. Additionally, animal models have been pivotal in understanding the complexities of human organ systems, such as the heart and lungs, aiding in the development of treatments and surgical techniques. These discoveries have laid the groundwork for advances in medical science and improved health outcomes.