THE INTRAMUSCULAR INNERVATION OF THE HUMAN INTERARYTENOID MUSCLE

The nerve supply of the human interarytenoid (IA) muscle has been cont roversial for more than a century. In this study the contribution of t he recurrent and superior laryngeal nerves to the IA was investigated in 10 adult human larynges. The larynges were obtained from autopsies and processed with the modified Sihler's technique which clears soft t issue while staining nerve. The LA muscles were dissected off the spec imens and transilluminated to demonstrate their nerve supply. The resu lts demonstrated that all 10 IA muscles were bilaterally innervated by both recurrent laryngeal nerves (RLNs) as well as branches of both su perior laryngeal nerves (SLNs). These nerves combined within the IA mu scles to form a dense anastomotic plexus which was highly variable bet ween specimens. The exact nature of the internal SLN neurons, whether motor or sensory, their innervation targets, or their function, were n ot discernible. Additional anatomic findings were the presence of larg e neural communications directly between the SLN and RLN, and smaller neural connections from side to side. All of these results disagree wi th currently accepted descriptions of laryngeal neuroanatomy.