There are two versions of this set of worksheets in this file. The first is for adults because it includes reproductive organs. The worksheet toward the end is for children/adolescents or more conservative students/countries (it excludes reproductive organs). There is a basic organ and vocabulary matching exercise, a body that students can label to revise, a verbs section which helps them use the correct verbs for the functions of the body and a question/discussion section. You can pick and choose what suits your class best. I did this after some pre-intermediate science students wanted to learn the basics of what is inside! This should take 40 mins - 1.5 hours depending on how you use it. It is fairly straight forward and could work for a good adult elementary class - intermediate. I am not a medic, just have a humble Arts degree, but I hope this can help some of you!