Assertion: muscle fiber's muscle | /r/HasAspect | motor units
Facets:
Source sentences:
text: The number of muscle fibers within each unit can vary within a particular muscle and even more from muscle to muscle; the muscles that act on the largest body masses have motor units that contain more muscle fibers, whereas smaller muscles contain fewer muscle fibers in each motor unit.
text: Motor units are organized slightly differently in invertebrates; each muscle has few motor units (typically less than 10), and each muscle fiber is innervated by multiple neurons, including excitatory and inhibitory neurons.