Schrøder H D
Anat Embryol (Berl). 1981;162(4):443-53. doi: 10.1007/BF00301870.
The first, second and third sacral segments of 59 human spinal cords were examined in order to localize and describe Onuf's nucleus X. The nucleus was found to be situated in the ventral horn of the segments S2 and S3; only in very few spinal cords did it extend into S1. A significant variation in the length of the nucleus was observed. Based on the cytoarchitecture the nucleus could be divided in three parts, a cranial, a dorsomedial and a ventrolateral. All parts of the nucleus consisted of chromatin-rich medium-sized neurons, and apparent direct appositions between different cells bodies as well as between cell bodies and large dendrites were observed. Characteristic findings in the neuropil surrounding the nucleus were the sparsity of myelinated fibers and the presence of dendritic bundles. The present observations are compared to the descriptions of a morphologically similar nucleus in experimental animals and a high degree of resemblance is found. As this nucleus in the experimental animals has been demonstrated to innervate muscles of the pelvic floor, including the striated sphincters of the urethra and the anus, it is suggested that the human Onuf's nucleus X has the same function.
为了定位并描述奥努夫核X，对59例人类脊髓的第一、第二和第三骶节段进行了检查。发现该核位于S2和S3节段的腹角；仅在极少数脊髓中它延伸至S1。观察到该核的长度存在显著差异。基于细胞结构，该核可分为三个部分，即颅侧部、背内侧部和腹外侧部。该核的所有部分均由富含染色质的中等大小神经元组成，并且观察到不同细胞体之间以及细胞体与大树突之间明显的直接并置。该核周围神经毡的特征性发现是有髓纤维稀少以及存在树突束。将本观察结果与实验动物中形态学相似核的描述进行比较，发现有高度相似性。由于已证明实验动物中的这个核支配盆底肌肉，包括尿道和肛门的横纹括约肌，因此提示人类奥努夫核X具有相同功能。
