Shefchyk Susan J
Department of Physiology, University of Manitoba, Winnipeg, MB R3E 3J7, Canada.
Prog Brain Res. 2002;137:71-82. doi: 10.1016/s0079-6123(02)37008-0.
The storage and elimination of urine requires the coordination of activity between the autonomic nervous system (thoracolumbar sympathetic and sacral parasympathetic divisions) controlling the urinary bladder and urethra and the lumbosacral somatic motoneurons innervating the striated sphincter and pelvic floor muscles. These three efferent systems involved in the control of lower urinary tract function receive segmental sensory information from various visceral organs and the perineum, as well as inputs from supraspinal regions. Ascending and descending connections between the various spinal segments levels and supraspinal regions provide the reflex substrates participating in normal bladder continence and micturition reflexes. Many of the actions of descending and segmental reflexes are mediated by excitatory and inhibitory sacral spinal interneurons located within the region of the parasympathetic preganglionic autonomic neurons and the sphincter ventral horn motoneurons. This review will: (1) discuss the basic organization and spinal elements of the reflex pathways subserving continence and micturition; (2) describe features of the identified sacral interneuronal circuitry contributing to the control of the bladder and sphincter function; and (3) discuss how changes in the control of these reflex pathways and neurons may contribute to abnormal patterns of bladder and sphincter function commonly observed following spinal cord injury.
尿液的储存和排出需要自主神经系统（胸腰段交感神经和骶段副交感神经）之间的活动协调，自主神经系统控制膀胱和尿道，而腰骶部躯体运动神经元支配横纹肌括约肌和盆底肌肉。这三个参与控制下尿路功能的传出系统接收来自各种内脏器官和会阴的节段性感觉信息，以及来自脊髓上区域的输入。不同脊髓节段水平与脊髓上区域之间的上下行连接提供了参与正常膀胱节制和排尿反射的反射基础。下行和节段性反射的许多作用是由位于副交感神经节前自主神经元区域和括约肌腹角运动神经元内的兴奋性和抑制性骶段脊髓中间神经元介导的。本综述将：（1）讨论维持节制和排尿的反射通路的基本组织和脊髓成分；（2）描述已确定的骶段中间神经元回路对膀胱和括约肌功能控制的特征；（3）讨论这些反射通路和神经元控制的变化如何导致脊髓损伤后常见的膀胱和括约肌功能异常模式。
