Final answer:
A muscle twitch graph shows three phases: latent period without tension, followed by a contraction phase with increased tension, and concluding with a relaxation phase where tension decreases.
Step-by-step explanation:
A graph of a muscle twitch (from a strip chart recorder) would have three distinct phases: a latent period, a contraction phase, and a relaxation phase. During the latent period, the muscle is preparing for contraction but no tension is produced. Next, the contraction phase occurs when Ca++ ions in the sarcoplasm bind to troponin, causing tropomyosin to move from actin-binding sites allowing cross-bridges to form and sarcomeres to shorten, leading to an increase in muscle tension. Eventually, during the relaxation phase, tension decreases as Ca++ ions are pumped out of the sarcoplasm and cross-bridge cycling stops, leading to muscle relaxation.