You've answered your own question.
I cannot think of more specific terms for any of those body parts, although I'm sure there are such terms. They're probably very technical and not used in day-to-day English. For example, one of the butt muscles is the gluteus maximus, but regular people wouldn't say such a thing, unless perhaps they wanted to poke fun at your behind.
I don't know what a "bellum" is. Did you mean to say "belly"? If so, most people would say "abs" or "ab muscles."
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