Structure and function of the external urethral sphincter (EUS)

1)对人男性尿路进行了电子显微镜观察，发现前列腺叶周围叶间质内有丰富的自主肾上腺素能神经供应。这些肾上腺素能纤维更多地作为自主神经传出下降到EUS，在那里它们形成所谓的表面连接，表明肾上腺素能参与人类EUS的功能。2)从超微结构上看，似乎有三种类型的横纹肌-两种类型的红肌和一种类型的白肌。3)在神经源性排尿功能障碍中，EUS的肌电活动与膀胱输尿管发热的严重程度和相关的肾脏狭窄相关。4)神经源性膀胱EUS的α-肾上腺素能激活似乎部分地与逼尿肌括约肌功能障碍(DSD)的发生有关这是这些受试者排尿功能障碍的主要原因。5)根治性TURP通过与壁内交感神经节切除术相当的效果缓解DSD，从而缓解排尿功能障碍。

1) On electron microscopic study of human male urethra there was a rich supply of autonomic adrenergic nerves in the interstitium of peripheral lobe of the prostatic urethra. These adrenergic fibers descended further more as autonomic efferents to the EUS, Wherein they formed so called surface junctions, suggesting adrenergic involvement in the function of human EUS.2) Ultrastructurally there seem to be three types of striated muscle - two types of red muscle and one type of white muscle.3) In neurogenic voiding dysfunction the activity of EUS as assessed by its electromyography was correlated ot the severity of vesicoureteral feflux and associated renal scarring.4) Alpha-adrenergic activation of EUS in neurogenic bladder seems to be partially responsible for the genesis of detrusor-sphincter-dyssynergia(DSD), a leading cause of voiding dysfunction among these subjects.5) Radical TURP relieves voiding dysfunction by relieving DSD through ist effects equivalent to intramural surgical sympathetectomy.