Qualitative changes in electrical reactions of muscle tissue are best described as:

• A. Sluggish contraction
• B. Hyperexcitability or hypoexcitability
• C. Maximal contraction
• D. A contraction which continues

Answer: (B)

Qualitative changes in electrical reactions of muscle tissue relate to excitability—the ease with which muscle fibers reach threshold and respond to stimulation. When tissue becomes hyperexcitable, it responds to weaker stimuli and fires more readily; when it becomes hypoexcitable, responses require stronger stimuli or are diminished. This concept focuses on the electrical readiness of the tissue, not just how fast or how strong a contraction is. The other phrases describe aspects of the contraction itself (speed, strength, or persistence) rather than changes in the electrical responsiveness of the muscle. Therefore, the best description is hyperexcitability or hypoexcitability.