Gacek R R, Malmgren L T, Lyon M J
Ann Otol Rhinol Laryngol. 1977 Nov-Dec;86(6 Pt 1):771-6.
Knowledge of the location of motor nerve fibers to the adductor and abductor muscles of the larynx may be useful in the diagnosis and treatment of innervation disorders in this organ. Anterograde degeneration and retrograde tracer anatomical techniques have demonstrated the central and peripheral positions of these two groups of motor nerve fibers in the cat. Traditional nerve fibers degeneration methods applied following intracranial transection of the vagus nerve rootlets indicated that: 1) Most of the fibers in the recurrent laryngeal nerve (RLN) are motor; 2) Almost all of these motor fibers leave the brain stem in the most rostral rootlet(s) of the vagus nerve; and 3) Motor fibers to the larynx form a discrete bundle within the trunk of the vagus nerve before forming the RLN. A tracer (horseradish peroxidase) of retrograde axoplasmic flow in motor neurons has been employed to demonstrate: 1) Dorsoventral division of the adductor and abductor neurons in the nucleus ambiguus; and 2) Diffuse arrangement of both adductor and abductor nerve fibers in the vagus nerve but collection of these fibers into abductor and adductor halves of the RLN prior to entering the larynx. These findings dispel theories of differential cord paralysis (Semon's law) based on a vulnerable position of abductor fibers at the periphery of the RLN. Furthermore, the diffuse arrangement of these fiber groups explains the usually mixed functional results obtained following reimplantation of the RLN into a laryngeal muscle.
了解支配喉内收肌和外展肌的运动神经纤维的位置，可能有助于诊断和治疗该器官的神经支配紊乱。顺行性变性和逆行示踪解剖技术已在猫身上证实了这两组运动神经纤维的中枢和外周位置。在颅内切断迷走神经根后应用传统的神经纤维变性方法表明：1）喉返神经（RLN）中的大多数纤维是运动性的；2）几乎所有这些运动纤维都从迷走神经最靠前的神经根离开脑干；3）支配喉部的运动纤维在形成喉返神经之前，在迷走神经干内形成一个离散的束。一种用于运动神经元逆行轴浆流示踪剂（辣根过氧化物酶）已被用于证实：1）疑核内收肌和外展肌神经元的背腹划分；2）内收肌和外展肌神经纤维在迷走神经中呈弥散分布，但在进入喉部之前，这些纤维聚集在喉返神经的外展肌和内收肌两半中。这些发现消除了基于喉返神经外周外展肌纤维易损位置的不同声带麻痹理论（塞蒙定律）。此外，这些纤维组的弥散分布解释了将喉返神经重新植入喉肌后通常获得的混合功能结果。
