"Tegmental" Natural Recordings by Native Speakers
There is no word "tegmental" in the English language. However, the word "segmental" might be close, but I think you might be thinking of the word "integral".
However, I found a word that is somewhat similar, "temperamental" which means having a tendency to have a bad temper, prone to mood swings; but this word is not related to structure or a part of a whole.
Another word "segmental" can refer to consisting of or divided into distinct parts or segments; related to structures that are disjointedly arranged one after the other.
But please note that "tegmental" is not a word in the English language as recognized by dictionaries.