title: Motor innervation of the cricopharyngeus muscle by the recurrent laryngeal nerve.
abstract: Patients with recurrent laryngeal nerve (RLN) paresis demonstrate impaired function of laryngeal muscles and swallowing. The cricopharyngeus muscle (CPM) is a major component of the upper esophageal sphincter. It was hypothesized that the RLN innervates this muscle. A nerve branch leading from the RLN to the CPM was found in adult sheep by anatomic dissection. Electrical stimulation of the RLN elicited a muscle action potential recorded by electrodes placed in the ipsilateral CPM. Swallowing was investigated by mechanical stimulation of oropharynx pre- and postsectioning of the RLN. Severing of the RLN resulted in a loss of the early phases of swallow-related CPM electromyographic activity; however, late-phase CPM electromyographic activity persisted. The RLN provides motor innervation of the CPM, which also has innervation from the pharyngeal plexus.
authors.affiliation: Department of Communication Processes and Disorders, University of Florida, Gainesville, Florida 32610, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Hammond
authors.forename: P W
authors.initials: PW
authors.lastname: Davenport
authors.forename: A
authors.initials: A
authors.lastname: Hutchison
authors.forename: R A
authors.initials: RA
authors.lastname: Otto
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003679:Deglutition / Q000502:physiology; D004558:Electric Stimulation; D004576:Electromyography; D009046:Motor Neurons / Q000502:physiology*; D010609:Pharyngeal Muscles / Q000033:anatomy & histology / Q000294:innervation*; D012009:Recurrent Laryngeal Nerve / Q000502:physiology*; D012756:Sheep