Omitting ',' or not in the case of ', from the cellular level to the organ-system level,'

Question

I read through my textbook and encountered this quote 'Homeostasis is a dynamic condition. In response to changing conditions, the body's parameters can shift among points in a narrow range that is compatible with maintaining life... Each structure , from the cellular level to the organ-system level, contributes in some way to keeping the internal environment of the body within normal limits'

I don't believe I should omit ',' as I am sure all of the structures in the human body can range actually from the cellular level to the organ-system level. So ', from the cellular level to the organ-system level,' is actually a non-relative clause phrase. But I can be wrong. I tried to write the original sentence in its full form and make 1 example to make it more clear. Could anyone help me with the 2 sentences?

1. Original sentence: Each structure , which are from the cellular level to the organ-system level, contributes in some way to keeping the internal environment of the body within normal limits

2. My own sentence: All of the structures in the human body, which range from the cellular level to the organ system level, contributes in some way to keeping the internal environment of the body within various normal limits

Thank you!

Answer 1

I believe you have simply misunderstood what the original sentence means. (P.S. Note the positioning of the comma - it should be right next to 'structure')

Each structure, from the cellular level to the organ-system level, contributes in some way to keeping the internal environment of the body within normal limits.

I interpret this to mean:

Each structure, from cellular level structures (e.g. mitochondria) to organ-system level structures (e.g. kidneys), contributes in some way to keeping the internal environment of the body within normal limits.