While I'm biased—being the OP of the question in question—I think the question is only broad but not too broad.
I'm not asking how an alien language could look (or sound) like—that would indeed lead to "really endless [..] possibilities". On the contrary, I'm precisely asking about features in human languages that are based on our anatomy. A reasonable restriction about the anatomical parts is not very helpful—if I had restricted it to our ears or eyes of number of limbs it would void the usefulness of the question, which is to find out which are concepts I hadn't thought about myself. It is also to be kept in mind that all might be a correct answer to somehow open questions.
Furthermore, the overall setting does set certain barriers, the amount of language concepts is certainly a limited number and not necessarily a very high one of that. Moreover, the focus on anatomy does restrict the influence vectors on language quite considerably. It excludes for example more environmental, societal and cultural factors which we are also discussing on this site.
Finally, the already given answer shows that the question is indeed answerable.