<Ul> <Li> Alpha motor neurons (α - MNs) innervate extrafusal muscle fibers, the most numerous type of muscle fiber and the one involved in muscle contraction . </Li> <Li> Beta motor neurons (β - MNs) innervate intrafusal fibers of muscle spindles with collaterals to extrafusal fibers (type of slow twitch fibers). </Li> <Li> Gamma motor neurons (γ - MNs) innervate intrafusal muscle fibers, which together with sensory afferents compose muscle spindles . These are part of the system for sensing body position (proprioception). </Li> </Ul> <Li> Alpha motor neurons (α - MNs) innervate extrafusal muscle fibers, the most numerous type of muscle fiber and the one involved in muscle contraction . </Li> <Li> Beta motor neurons (β - MNs) innervate intrafusal fibers of muscle spindles with collaterals to extrafusal fibers (type of slow twitch fibers). </Li> <Li> Gamma motor neurons (γ - MNs) innervate intrafusal muscle fibers, which together with sensory afferents compose muscle spindles . These are part of the system for sensing body position (proprioception). </Li>

Where do the lower motor neurons supplying the skeletal muscle of the head arise