存储和尿定期消除依赖于在两个功能单元的下泌尿道,即一个贮存器(膀胱)和组成的电源插座中的膀胱颈,尿道的协调活动的光滑和横纹肌和尿道sphincter1,2。这些器官之间的协调是一个复杂的,位于脑,脊髓和外周神经节的神经网络控制系统介导的。
The storage and periodic elimination of urine depend on the coordinated activity of smooth and striated muscles in the two functional units of the lower urinary tract, namely a reservoir (the urinary bladder) and an outlet consisting of the bladder neck, the urethra and the urethral sphincter1,2. The coordination between these organs is mediated by a complex neural control system that is located in the brain, the spinal cord and the peripheral ganglia.
下尿路在几个方面不同于其他内脏结构。首先,它依赖于中枢神经系统的控制结构,保持水平的功能区分开来,即使输入外源性神经已经被淘汰。这是不寻常的活动模式和其在组织中的神经控制机制。
The lower urinary tract differs from other visceral structures in several ways. First, its dependence on CNS control distinguishes it from structures that maintain a level of function even after the extrinsic neural input has been eliminated. It is also unusual in its pattern of activity and in the organization of its neural control mechanisms.
For example, the bladder has only two modes of operation: storage and elimination. Thus, many of the neural circuits that are involved in bladder control have switch-like or phasic patterns of activity, unlike the tonic patterns that are characteristic of the autonomic pathways that regulate cardiovascular organs. In addition, micturition is under voluntary control and depends on learned behaviour that develops during maturation of the nervous system, whereas many other visceral
https://www.51lunwen.org/ygjylw/
functions are regulated involuntarily.
Owing to the complexity of the neural mechanisms that regulate bladder control, the process is sensitive to
various injuries and diseases. This Review summarizes the results of recent studies in animals and humans that have provided new insights into the sensory and motor
mechanisms that underlie voluntary and reflex micturition,the changes in neural pathways that occur following disease or injury that alters lower-urinary-tract function,and new therapies for the treatment of neurogenic bladder dysfunction.
Peripheral innervation of the urinary tract The requirement for voluntary control over the lower urinary tract necessitates complex interactions between
autonomic (mediated by sympathetic and parasympathetic nerves) and somatic (mediated by pudendal nerves)efferent pathways1,2 (FIG. 1a). The sympathetic innervation arises in the thoracolumbar outflow of the spinal cord, whereas the parasympathetic and somatic innervation originates in the sacral segments of the spinal cord.
Afferent axons from the lower urinary tract also travel in these nerves.Sympathetic postganglionic nerves — for example,the hypogastric nerve — release noradrenaline, which activates β‑adrenergic inhibitory receptors in the detrusor muscle to relax the bladder, α‑adrenergic excitatory receptors in the urethra and the bladder neck, and α‑ and β‑adrenergic receptors in bladder ganglia3,4 (FIG. 1b).Parasympathetic postganglionic nerves release both cholinergic (acetylcholine, ACh) and non-adrenergic,non-cholinergic transmitters. Cholinergic transmission is the major excitatory mechanism in the human bladder4 (FIG. 1b). It results in detrusor contraction and consequent urinary flow and is mediated principally by the M3 muscarinic receptor, although bladder smooth
muscle also expresses M2 receptors5. Muscarinic receptors are also present on para
本论文由英语论文网提供整理,提供论文代写,英语论文代写,代写论文,代写英语论文,代写留学生论文,代写英文论文,留学生论文代写相关核心关键词搜索。