hypotonus vs tonus

hypotonus and tonus both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypotonus	Yes	No	No	No
tonus	Yes	No	No	No

As nouns, tonus is a hypernym of hypotonus; that is, tonus is a word with a broader meaning than hypotonus:

hypotonus: (of muscular tissue) the state of being hypotonic
tonus: the elastic tension of living muscles, arteries, etc. that facilitate response to stimuli

Other hypernyms of hypotonus include tone, tonicity.

hypotonus (noun)	tonus (noun)
(of muscular tissue) the state of being hypotonic	the elastic tension of living muscles, arteries, etc. that facilitate response to stimuli