目的    为大鼠迷走神经移位膈神经重建高位颈髓损伤大鼠的膈肌功能提供显微解剖学依据。  方法　10只健康雌性SD大鼠在10倍手术显微镜下解剖双侧膈神经、迷走神经及其分支。用数显卡尺测量迷走神经与膈神经在“膈神经主干起始平面”、“锁骨上平面”、“入膈肌平面”的相对距离，用读数显微镜测量各平面迷走神经和膈神经的直径。   结果　在颈部，迷走神经直径为（0.3284±0.0247）mm，膈神经直径为（0.2267±0.0164）mm，二者的相对距离很接近，无论是在“膈神经主干起始平面”还是“锁骨上平面”，平均都不超过2.5 mm；在“入膈肌平面”平面，迷走神经直径为（0.2912±0.0326）mm，膈神经直径为（0.2794±0.0282）mm，二者的相对距离较颈部远，左侧为（8.71±0.804）mm，右侧为（6.203±0.952） mm。   结论　(1)在颈部，迷走神经与膈神经的直径相差不大，相对距离很接近，二者可直接无张力缝合。(2)在入膈肌平面，迷走神经与膈神经的直径大致相同，相对距离稍远，但将膈神经和迷走神经向上游离一段距离后仍可实现二者的直接无张力缝合。

Objective　To provide micro-anatomical basis for recovering diaphragmatic function after cervical spinal injury by vagus nerve transposition to phrenic nerve.   Methods   10 healthy female SD rats were dissected to free the bilateral phrenic nerves, the vagus nerves and their branches under the surgical microscope. The distances between the vagus nerve and the phrenic nerve were measured by a sliding caliper(precision of 0.01mm) at "the phrenic nerve trunk originated level", "supraclavicula level" and "the level of diaphragma", and then the diameters of vagus nerves and phrenic nerves at the levels mentioned above were measured by microscope (precision of 0.0025mm) respectively.   Results    The diameter of vagus nerves was bigger than that of phrenic nerves by one third at the cervical part [the diameter of vagus nerve was （0.3284±0.0247）mm，phrenic nerve （0.2267±0.0164）mm], and the distance between them was no more than 2.5mm either at "the phrenic nerve trunk originated level" or at "supraclavicula level". At the "the level of diaphragma", the diameters of both nerves were roughly the same [vagus nerve was（0.2912±0.0326）mm，and phrenic nerve （0.2794±0.0282）mm], and at this level, the distance between them was (8.71±0.804) mm and (6.203±0.952) mm on the left and right sides respectively.   Conclusions    The diameters of vagus nerves and the phrenic nerves are not different so much in the cervical part. The two nerves get close to each other, therefore, it is possible to suture them directly without any tension, especially at "the level of diaphragma".