PHYSIOLOGY
SYNAPTIC PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a bundle of nerve muscle fibers.
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a group of muscle fibers controlled by one nerve.
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the elongated contractile threads found in striated muscle cells.
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None of the above
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Detailed explanation-1: -A motor unit, the functional unit of muscle contraction, is a single motor nerve and the associated muscle fibers that are innervated upon stimulation from the nerve. A collection of motor units is referred to as a motor pool .
Detailed explanation-2: -A single motor neuron, however, can innervate many muscle fibers. The combination of an individual motor neuron and all of the muscle fibers that it innervates is called a motor unit.
Detailed explanation-3: -In muscles involved with fine, coordinated control, the motor units are very small with 3-5 muscle fibers per motor neuron. Muscles that control eye movement and muscles in our hands have relatively small motor units.
Detailed explanation-4: -Each skeletal muscle fiber has one neuromuscular junction. A motor unit consists of a neuron plus the muscle fibers it supplies. There are many motor units in a nerve that collectively provide electrical input to a muscle to generate a muscle contraction.
Detailed explanation-5: -The combination of a single motor neuron and all of the muscle fibers it controls is called a motor unit (see the figure below).