10/11/22 page 1 Nama : Naili Mumtazati
NIM :4111211025 Kelompok : B (B.1)
Name: Naili M, Raissa I
Exercise 2: Skeletal Muscle Physiology: Activity 7: Isotonic Contractions and the Load-Velocity Relationship Lab Report
Pre-lab Quiz Results
You scored 100% by answering 5 out of 5 questions correctly.
1. During an isotonic concentric contraction, the
You correctly answered: b. force generated by the muscle is greater than the weight of the attached load.
2. During an isotonic concentric contraction
You correctly answered: b. the latent period increases with heavier loads.
3. During the latent period for an isotonic concentric contraction
You correctly answered: c. cross bridges cycle and, when muscle tension exceeds the load, muscle shortening occurs.
4. Muscle shortening velocity
You correctly answered: a. decreases with heavier loads.
5. An isotonic contraction of a muscle is one in which You correctly answered: a. the length of the muscle changes.
10/11/22 page 2 Experiment Results
Predict Question:
Predict Question: As the load on the muscle increases, what will happen to the latent period, the shortening velocity, the distance that the weight moves, and the contraction duration?
Your answer : c. The latent period will decrease, the shortening velocity will decrease, the distance will increase, and the contraction duration will increase.
Stop & Think Questions:
What kind of contraction did you observe when you attached the 2.0 gram weight to the skeletal muscle and stimulated a contraction?
You correctly answered: c. isometric Experiment Data:
Voltage Length Weight Velocity
(mm/msec)
Twitch Duration (msec)
Distance Lifted (mm)
8.5 75 0.5 0.100 78.00 4.0
8.5 75 1.0 0.057 49.00 2.0
8.5 75 1.5 0.022 30.00 0.5
8.5 75 2.0 0.000 0.00 0.0
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10/11/22 page 5 Post-lab Quiz Results
You scored 100% by answering 6 out of 6 questions correctly.
1. Which of the weights allowed the fastest muscle shortening velocity?
You correctly answered: a. 0.5-g weight
2. Which of the weights induced the longest latent period of the muscle contraction?
You correctly answered: c. 1.5-g weight
3. Which weight did the muscle contraction move the greatest distance?
You correctly answered: a. 0.5-g weight
4. Which of the weights allowed the longest duration of muscle contraction?
You correctly answered: a. 0.5-g weight
5. An isotonic contraction of a muscle is one in which You correctly answered: a. the length of the muscle changes.
6. When lifting a heavy load
You correctly answered: d. the muscle shortening velocity is decreased in comparison with lighter loads.
10/11/22 page 6 Review Sheet Results
1. If you were using your bicep muscles to curl a 7-kg dumbbell, when would your muscles be contracting isotonically?
Your answer:
saat saya mengangkat tangan dari posisi lurus kebawah lalu keatas, dan saat mengembalikan lengan ke posisi bawah
2. Explain why the latent period became longer as the load became heavier in the experiment. How well did the results compare with your prediction?
Your answer:
prediksi saya dan hasil percobaan terkait berbeda, saya memprediksi periode laten akan berkurang, tetapi periode laten meningkat karena butuh lebih banyak waktu untuk mengumpulkan kekuatan baru
3. Explain why the shortening velocity became slower as the load became heavier in this experiment. How well did the results compare with your prediction?
Your answer:
prediksi saya berbeda dengan jawaban, karena periode laten meningkat, jarak bertambah, dan cepat pemendekan membutuhkan waktu lebih lama (meningkat) untuk mengangkat benda yang lebih berat, dan dengan demikian kontraksi membutuhkan waktu lebih lama (meningkat)
4. Describe how the shortening distance changed as the load became heavier in this experiment. How well did the results compare with your prediction?
Your answer:
prediksi saya benar, kecepatan pemendekan berkurang dengan peralatan yang lebih berat.
5. Explain why it would take you longer to perform 10 repetitions lifting a 10-kg weight than it would to perform the same number of repetitions with a 5-kg weight.
Your answer:
dengan peningkatan berat datang peningkatan waktu periode laten, sementara kecepatan pemendekan berkurang.
6. Describe what would happen in the following experiment: A 2.5-g weight is attached to the end of the isolated whole skeletal muscle used in these experiments. Simultaneously, the muscle is maximally stimulated by 8.5 volts and the platform supporting the weight is removed. Will the muscle generate force? Will the muscle change length? What is the name for this type of contraction?
Your answer:
kontraksi isometrik, otot akan menghasilkan kekuatan saat otot merenggang. berat alat berat akan menarik panjang otot kebawah, tetapi perubahan panjang otot ini bukan dari kontraksi, tetapi dari berat itu sendiri.
