Résumé
The anatomy, structure and innervation of the posterior cricoarytenoid muscle [PCA] were investigated in the goat as an animal model. The results revealed that the PCA muscle was composed of three bellies with distinct attachments and different angles of convergence of the muscle fibers onto the arytenoid cartilage with thin facial lamina in between the bellies. The nerve supply of the muscle arose as a single branch from the recurrent laryngeal nerve and entered the muscle through its lateral border and directed upwards and medially to end in the horizontal belly from the main nerve and branches sprouted to other bellies. SO, each belly was composed almost completely of dark muscle fibers, whereas the oblique and vertical bellies were formed of a mixture of pale and dark fibers. Silver impregnated sections illustrated simple and single motor endings supplied with relatively thin nerve fibers