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Updated: Jun 7, 2026

Retrograde Neuroanatomical Tracing of Phrenic Motor Neurons in Mice
Published on: February 22, 2018
[Anatomic research on the transposition of accessory nerve to phrenic nerve]
Ce Wang1, Wen Yuan, Xu-hui Zhou
1Department of Orthopaedics, Changzheng Hospital, Second Military Medical University, Shanghai, China.
Objective:
To comprehend the anatomic characteristics and correlations between the accessory nerve and the phrenic nerve in the adult corpses.
Methods:
The bilateral accessory nerves, phrenic nerves, and their branches of 20 adult corpses (38 sides) were underwent exposure. The morphologic data of the accessory nerves and the phrenic nerves above clavicle were measured. In addition, the minimal and maximal distances from several points on the accessory nerve to the full length of the phrenic nerve above clavicle were measured. Then, the number of motor nerve fibers on different locations of the nerves utilizing the method of immunohistochemistry were counted and compared.
Result:
The accessory nerves after sending out the sternocleido-mastoid muscular branches were similar in the morphologic data with the phrenic nerves. Meanwhile, the accessory nerve had a coiled appearance within this geometrical area. The possibly minimal distance between the accessory nerve and phrenic nerve was (3.19 ± 1.23) cm, and the possibly maximal distance between the starting point of accessory nerve and the end of the phrenic nerve above clavicle was (8.71 ± 0.75) cm.
Conclusions:
The accessory nerve and the phrenic nerve are similar in the anatomic evidences and the number of motor nerve fibers. And the length of accessory nerve is sufficiently long to connect with phrenic nerve as needed. It is possible to suture them without strain directly.
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