hypertonus vs tonicity

hypertonus and tonicity both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypertonus	Yes	No	No	No
tonicity	Yes	No	No	No

As nouns, tonicity is a hypernym of hypertonus; that is, tonicity is a word with a broader meaning than hypertonus:

hypertonus: (of muscular tissue) the state of being hypertonic
tonicity: the elastic tension of living muscles, arteries, etc. that facilitate response to stimuli

Other hypernyms of hypertonus include tone, tonus.

hypertonus (noun)	tonicity (noun)
(of muscular tissue) the state of being hypertonic	the elastic tension of living muscles, arteries, etc. that facilitate response to stimuli