Name: Linda Aulia Hia Aspara
Exercise 2: Skeletal Muscle Physiology: Activity 1: The Muscle Twitch and the Latent Period Lab Report Pre-lab Quiz Results
You scored 100% by answering 5 out of 5 questions correctly.
1. Skeletal muscles are connected to bones by You correctly answered: b. tendons.
2. Skeletal muscles are composed of hundreds to thousands of individual cells called You correctly answered: c. fibers.
3. The term motor unit refers to
You correctly answered: c. one motor neuron and all of the skeletal muscle fibers it innervates.
4. The motor neuron and muscle fiber intersect at what is called You correctly answered: d. the neuromuscular junction.
5. A twitch is
You correctly answered: a. one contractile response to a single action potential.
04/14/23 page 1
04/14/23 page 2 Experiment Results
Predict Question:
Predict Question: Will changes to the stimulus voltage alter the duration of the latent period?
Your answer : b. No, changing the stimulus voltage will not change the latent period duration.
Stop & Think Questions:
What is the period of time that elapses between the generation of an action potential and the start of muscle tension development in a muscle fiber?
You correctly answered: c. the latent period
What occurs during the latent period of these isometric contractions?
You correctly answered: b. All the steps of excitation-contraction coupling occur.
Experiment Data:
Voltage Length Active Force Passive Force Total Force Latent Period
0.0 75 0.0 0.0 0.0 ----
3.0 75 1.04 0.0 1.04 ----
4.0 75 1.32 0.0 1.32 2.40
6.0 75 1.65 0.0 1.65 2.80
8.0 75 1.81 0.0 1.81 2.40
10.0 75 1.82 0.0 1.82 2.80
04/14/23 page 3
04/14/23 page 4
04/14/23 page 5 Post-lab Quiz Results
You scored 100% by answering 6 out of 6 questions correctly.
1. An action potential in a motor neuron triggers the release of which neurotransmitter?
You correctly answered: b. acetylcholine 2. The term skeletal muscle fiber refers to
You correctly answered: a. an individual skeletal muscle cell.
3. The graded depolarization in the skeletal muscle fiber that is elicited in response to one action potential from the motor neuron is called
You correctly answered: c. an EPP (end-plate potential).
4. Which of the following is not a phase of a skeletal muscle twitch?
You correctly answered: b. hyperpolarization phase 5. A skeletal muscle twitch is
You correctly answered: a. one contractile response to a single action potential.
6. Which of the following correctly matches the twitch phase with its definition?
You correctly answered: d. the contraction phase: the time between the end of the latent period and peak muscle tension
04/14/23 page 6 Review Sheet Results
1. Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period.
Your answer:
serat otot rangka merupakan kumpulan jaringan serat otot rangka yang terorganisir yang disebut juga miofibril yang mengandung beberapa miofibril.
- unit motorik : merupakan kombinasi neuron motorik individu dan semua serat otot yang dipersarafi.
- kedutan otot rangka : merupakan periode kontraksu dan relaksasi otot setelahh satu rangsangan.
- stimulus listrik : yaitu ketika intensitas arus yang diberikan cukup untuk menginduksi konntraksi kontraksi otot.
- periode laten : yaitu penundaan singkat dari waktu ketika potensial aksi mencapai otot sampai ketegangan dapat diamati di otot.
2. What is the role of acetylcholine in a skeletal muscle contraction?
Your answer:
aseetilkoline dalam kontraksi otot rangka digunakan untuk memicu neuron motorik dan mengaktifkan kontraksi otot.
3. Describe the process of excitation-contraction coupling in skeletal muscle fibers.
Your answer:
coupling eksitasi-kontraksi merupakan proses dimana ion kalsium yang dilepaskan dari tangki terminal retikulum sarkoplasma mengubah peristiwa depolarisasi dalam sarkolema menjadi awal pemendekan mekanis miofibril di dalam miofiber.
4. Describe the three phases of a skeletal muscle twitch.
Your answer:
A. periode laten : merupakan penundaan singkat waktu ketika potensial aksi mencapai otot sampai ketegangan dapat diamati di otot.
B. faase kontraksi : yaitu ketika otot menghasilkan ketegangan dan dikaitkan dengan siklus siklus jembatan silang.
C. fase relaksasi : merupakan waktu bagi otto untuk kembali ke panjang normalnya.
5. Does the duration of the latent period change with different stimulus voltages? How well did the results compare with your prediction?
Your answer:
no, changing the stimulus voltage will not change the latent period duration.
6. At the threshold stimulus, do sodium ions start to move into or out of the cell to bring about the membrane depolarization?
Your answer:
iya betul, natrium akan bergerak masuk atau keluar dari sel untuk menghasilkan depolarisasi membran.
