Pacheco P, Camacho M A, García L I, Hernández M E, Carrillo P, Manzo J
Instituto de Neuroetología, Universidad Veracruzana, Xalapa, México.
Brain Res. 1997 Jul 25;763(2):202-8. doi: 10.1016/s0006-8993(97)00408-3.
Surgical microscopy and electrophysiological techniques were used to standardize the nomenclature for the pudendal nerve and sacral plexus according to their somatic axonal composition in the male rat. We conclude that the pudendal nerve is the segment running from the L6-S1 trunk to the sacral plexus, carrying efferent fibers to the coccygeus, internal obturator, ventral and dorsal bulbospongiosus, ischiocavernosus, external anal sphincter, and external urethral sphincter muscles, and afferent fibers from the penis, prepuce, scrotum, and ventral-proximal tail. The sacral plexus is the complex formed by the bridge-like structure connecting the pudendal nerve with the lumbosacral trunk, and two nerve branches emerging from it, one innervating the proximal half of the scrotal skin, and the other innervating the muscles at the base of the penis known as the motor branch. These branches are only considered as a part of the sacral plexus because they integrate axons from both the lumbosacral trunk and pudendal nerve. The gross anatomy of the pudendal nerve and sacral plexus has a main organization that was observed in 70% of cases, whereas the remaining 30% occurred in two variants. This nomenclature is appropriate to describe the pudendal nerve and sacral plexus in studies that involve them being lesioned or electrophysiologically analysed. A main additional finding was that two large afferent branches innervate the scrotum, one the proximal half and the other the distal half. As mentioned above, the proximal branch belongs to the sacral plexus, whereas the distal branch belongs to the pudendal nerve because all its axons travel to the cord via this nerve. Since stimulation or even manipulation of the scrotal branches resulted in the secretion of semen containing spermatozoa, it is suggested that scrotal afferents are involved in some way in the ejaculatory process, a topic that deserves further research.
采用手术显微镜和电生理技术，根据雄性大鼠的躯体轴突组成，对阴部神经和骶丛的命名进行标准化。我们得出结论，阴部神经是从L6 - S1干延伸至骶丛的节段，它携带传出纤维至尾骨肌、内收肌、腹侧和背侧球海绵体肌、坐骨海绵体肌、肛门外括约肌和尿道外括约肌，以及来自阴茎、包皮、阴囊和尾腹侧近端的传入纤维。骶丛是由连接阴部神经与腰骶干的桥状结构以及由此发出的两个神经分支形成的复合体，其中一个分支支配阴囊皮肤的近端一半，另一个分支支配阴茎基部的肌肉，即运动支。这些分支仅被视为骶丛的一部分，因为它们整合了来自腰骶干和阴部神经两者的轴突。阴部神经和骶丛的大体解剖结构在70%的病例中具有主要的组织形式，而其余30%则出现两种变异形式。这种命名法适用于在涉及阴部神经和骶丛损伤或电生理分析的研究中对它们进行描述。另一个主要发现是，有两个大的传入分支支配阴囊，一个支配近端一半，另一个支配远端一半。如上所述，近端分支属于骶丛，而远端分支属于阴部神经，因为其所有轴突都通过该神经传至脊髓。由于刺激甚至操作阴囊分支会导致含有精子的精液分泌，因此提示阴囊传入神经在射精过程中以某种方式发挥作用，这一话题值得进一步研究。
