Figure 5.

Non-selective reinnervation of muscles after peripheral nerve surgery. The diagrammatic representation of the innervation of the intrinsic abductor (AB) and adductor (AB) muscles of the vocal cords by inspiration and phonation (speaking) in normal (A), denervated (B), and reinnervated (C) intrinsic muscles. The large and small motoneurons innervating the AB and AD muscles, respectively, represents the 4:1 ratio of the number of the motoneurons innervating the AB and AD muscles. After bilateral denervation, the vocal cords do not close during phonation so that speech is severely impaired (B). After surgical repair of the laryngeal nerve, the axotomized motoneurons randomly reinnervate the AB and AD muscles (C) with the result that the vocal cords are effectively paralyzed in a position of openness that disallows effective speech. Adapted from [104].