Motor end-plate distribution in the human lateral cricoarytenoid muscle.

Knowledge of the neuromuscular junction distribution in the intrinsic laryngeal muscles has potential clinical application in directing procedures that affect the function of these muscles through their neuromuscular junctions. We used histochemical techniques and computer graphics to determine the three-dimensional distribution of the motor end-plates in the human lateral cricoarytenoid muscle. In contrast to the results that have been reported for the human thyroarytenoid, cricothyroid, and posterior cricoarytenoid muscles, where end-plates are more diffusely distributed, the results of our study indicate that in the human lateral cricoarytenoid muscle, the neuromuscular junctions are generally found within a broad band at the midlength of the muscle. This more focused distribution should be advantageous clinically in facilitating the manipulation of the motor end-plates in this muscle.