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Motor unit

Motor Unit: One nerve fiber (nerve cell axon) and all of the muscles cells (fibers) it innervates.
  • Example - Although a single muscle cell must fire completely or not at all, force output can be calibrated by the number and size of motor units recruited.
  1. Saladin, K. (2012). Anatomy & Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.