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EXERCISE 2: Skeletal Muscle Physiology
Student Name: Student ID#:
ACTIVITY 1: The Muscle Twitch and the Latent Period
Answers
1. The latent period of the skeletal muscle that was tested in this lab simulation was
a. about 1 second.
b. less than 1 msec.
c. between 2-3 msec.
d. variable, depending on the voltage that was applied to it.
C.
2. True or False: Another name for a muscle cell is “myofibril.”
False
3. The largest active force that could be generated in the muscle is Activity 1 was _______ grams.
1.82
4. Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period.
Skeletal muscle fiber- usually attached to the skeleton, helps humans make voluntary decisions to walk, talk and sit up.
Motor Unit- consists of a motor neuron and all of the muscle fibers it innervates/supplies.
Skeletal muscle twitch- a brief contraction of all the muscle fibers in a motor unit in response to a single action potential in its motor neuron. A twitch has three phases. Latent, contraction, and relaxation phase
Electrical stimulus- used to control muscle contractions
Latent period- the period of time that elapses between the generation of an action potential in a muscle cell and the start of a muscle contraction
5. What is the role of acetylcholine (ACh) in a skeletal muscle contraction?
Acetylcholine diffuses into the muscle fiber’s plasma membrane and binds to receptors in the motor end plate starting a change in ion permeability that results in a graded depolarization of the muscle plasma membrane.
6. Describe the process of excitation-contraction coupling in skeletal muscle fibers.
A shock is sent to thru the muscle, leading into the contraction of the of the muscle
7. Describe the three phases of a skeletal muscle twitch.
Latent period – the period of time that elapses between the generation of an action potential in a muscle cell and the start of a muscle contraction.
Student Name: Student ID#:
ACTIVITY 1: The Muscle Twitch and the Latent Period
Answers
1. The latent period of the skeletal muscle that was tested in this lab simulation was
a. about 1 second.
b. less than 1 msec.
c. between 2-3 msec.
d. variable, depending on the voltage that was applied to it.
C.
2. True or False: Another name for a muscle cell is “myofibril.”
False
3. The largest active force that could be generated in the muscle is Activity 1 was _______ grams.
1.82
4. Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period.
Skeletal muscle fiber- usually attached to the skeleton, helps humans make voluntary decisions to walk, talk and sit up.
Motor Unit- consists of a motor neuron and all of the muscle fibers it innervates/supplies.
Skeletal muscle twitch- a brief contraction of all the muscle fibers in a motor unit in response to a single action potential in its motor neuron. A twitch has three phases. Latent, contraction, and relaxation phase
Electrical stimulus- used to control muscle contractions
Latent period- the period of time that elapses between the generation of an action potential in a muscle cell and the start of a muscle contraction
5. What is the role of acetylcholine (ACh) in a skeletal muscle contraction?
Acetylcholine diffuses into the muscle fiber’s plasma membrane and binds to receptors in the motor end plate starting a change in ion permeability that results in a graded depolarization of the muscle plasma membrane.
6. Describe the process of excitation-contraction coupling in skeletal muscle fibers.
A shock is sent to thru the muscle, leading into the contraction of the of the muscle
7. Describe the three phases of a skeletal muscle twitch.
Latent period – the period of time that elapses between the generation of an action potential in a muscle cell and the start of a muscle contraction.