A number of software packages provide students with excellent introductions to mammalian anatomy. These programs can supplement our work with the animals, but an image on a screen cannot help you appreciate the texture of the lung which is so essential to that organ's function. If you decide that an animal system is essential to your work, then you need to select an appropriate system. In this case ethical considerations focus on minimizing the amount of pain and suffering experienced by the animal. Other considerations include selection of an animal model that will satisfy your research objectives at the lowest cost and with the most efficient use of laboratory space.
Fetal pigs make a good choice for introductory biology dissection exercises.
Fetal pigs provide a dissection subject sufficiently large for manipulation by those unskilled at dissection, but small enough to store and ship easily. For its size, the fetal pig represents a rather economical d issection subject. For some reason, the public becomes much more concerned over the use of warm blooded vertebrate animals then over the use of invertebrates and cold blooded vertebrates. Most of the cold blooded specimens we will use were captured in the field, killed, and preserved. Ethical decisions regarding the use of animals for research and teaching are highly personal matters.