Muscle Physiology Lab: Muscle Twitch Study

Muscle Physiology Lab Assignment Part I: Muscle Twitch Study the Data

Muscle Physiology Lab Assignment Part I: Muscle Twitch Study the data for the three muscles in Tables 1A, 1B, and 1C. Make a scatter plot graph in Microsoft Excel® using these data tables that show the twitch tension timelines of the eye, rectus femoris, and plantaris muscle fibers. Connect the data points sequentially for each muscle. Refer to the section in the Introduction of the lab manual titled “Computer Graphing Using Microsoft Excel®” for assistance with this process. Additionally, graph the rectus femoris muscle, labeling the latent period, contraction phase, and relaxation phase.

Part II involves analyzing muscle fatigue by plotting the total time it took for fatigue to set in during each trial, following the procedure on page 220 of the lab manual.

Part III requires recreating a chart in Excel to display data on isometric and isotonic contractions, based on the procedure on page 222. The chart should include the following data table:

| Tension | Length | Type of Contraction |

| --- | --- | --- |

| Trial 1 | | |

| Trial 2 | | |

| Trial 3 | | |

---

Paper For Above instruction

The objective of this lab assignment is to analyze different aspects of muscle physiology, focusing on twitch responses, fatigue, and contractions. By creating detailed graphs and charts using Excel, students develop a comprehensive understanding of muscle behavior under various conditions.

The first part of the assignment emphasizes the visualization of muscle twitch responses in three different muscles: the eye, rectus femoris, and plantaris. Using data provided in Tables 1A, 1B, and 1C, students should generate scatter plots depicting the tension timeline for each muscle. This process involves plotting individual data points representing tension over time and connecting these sequentially to illustrate the muscle's response. Connecting the dots in sequence makes it easier to observe the characteristic features of twitch responses, such as the latency, contraction, and relaxation phases.

Particularly, attention must be given to the rectus femoris muscle, where students are tasked with identifying and labeling the latent period — the time between stimulus application and the beginning of contraction, the contraction phase itself — when tension increases, and the relaxation phase — when tension returns to baseline. Properly labeling these phases enhances understanding of the muscle’s electrical and mechanical responses.

The second segment of the lab explores muscle fatigue. Following a specified protocol, students will analyze how long it takes for fatigue to establish during repeated stimulations. This involves plotting the total time for fatigue onset across multiple trials, providing insight into how different factors influence muscle endurance and recovery. This data can reveal differences based on muscle type, intensity of stimulation, or experimental conditions.

Finally, in Part III, the focus shifts to the comparison between isometric and isotonic contractions. Students are expected to recreate a data chart in Excel showing tension generated during different types of contractions across multiple trials. The data table must include the tension produced, the length of the muscle during contraction, and the type of contraction (either isometric, where muscle length remains constant, or isotonic, where muscle length changes). Such visualization allows for analysis of how contraction types influence muscle strength and behavior.

Throughout this laboratory exercise, proficiency in Excel graphing techniques is essential. Proper labeling, data representation, and clear presentation of phases within the graph strengthen interpretive skills and provide clearer insights into muscle physiology.

In conclusion, this lab assignment integrates data analysis, graphing, and interpretation of muscle responses to stimuli, fatigue, and contraction types. These skills are foundational for understanding muscular function and form the basis for more advanced studies in physiology and biomechanics.

References

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  • McArdle, W. D., Katch, F. I., & Katch, V. L. (2015). Exercise Physiology: Nutrition, Energy, and Human Performance (8th ed.). Lippincott Williams & Wilkins.
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