Which of the following best describes muscle B compared with muscle A?
Muscle B is characteristic of a slow-twitch muscle (type 1) composed of predominantly slow-twitch muscle fibers. These fibers are smaller in size and are innervated by smaller nerve fibers. They typically have a more extensive blood supply, a greater number of mitochondria, and large amounts of myoglobin, all of which suppo high levels of oxidative phosphorylation.
Adapted for rapid contraction
Composed of larger muscle fibers
Fewer mitochondria
Innervated by smaller nerve fibers
Muscle