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Definition

noun

(1) The muscle in a steady partially contracted state caused by the successive flow of nerve impulses.

(2) The amount of tension or resistance to movement in a muscle.

Supplement

Muscle tonus helps in maintaining body posture. For instance, the muscles holding the jaw keep it in position with a continuous and partial contraction. When a person sleeps or loses consciousness, the muscle tonus declines.

Word origin: tonus » Greek tónos (tone)

Synonyms:

• muscular tonus
• muscle tone
• residual muscle tension
• tonus

See also: hypotonia, hypertonia.