Body Walk was a program we did in Champaign County for 6 years. We had a number of interactive displays starting with the mouth, esophagus, stomach, intestines, heart, lungs, and bones. It was likely similiar to the ones you say about Missouri and Kansas. However, we only did it here for 5th grade and homeschooled children and we no longer do it. It became to expensive for the schools to drive busses to the exhibits and participation started lessening. We held ours in the National Guard Armory in Urbana.
I am sure there's still organizational information around here if you would like more information about how we put on the program. Contact our 4-H secretary at our office number for more information.
I am not sure if other counties are doing something like this or not. You can always see the Extension office closest to you by looking on www.extension.uiuc.edu/state and clicking on the "Find a County" or "Find a staff person" for more information.