URINE RETENTION AND URINE LEAKAGE DISORDERS

摘要

Micturition is the normal process of storage and voiding of urine. Disorders of micturition encompass problems with urine storage (i.e., leakage or kicontinence) and bladder emptying (i.e., urine retention). Micturition is controlled by a combinationof autonomic and somatic innervation. Sympathetic innervation to the bladder via the hypogastric nerve is composed of preganglionic fibers exiting the lumbar spinal cord from the LI-4 spmal cord segments and synapsmg in the caudal mesenteric ganglion. Beta-adrenergic fibers terminate m the detrusor muscle; stimulation results in detrusor muscle relaxation and facilitates bladder filling. Alpha-adrenergic fibers innervate the smooth muscle fibers in the trigone and urethra, resulting in contraction of these muscle fibers to form a functional internal urethral sphincter. The normal storage phase is created by sympathetic autonomic domination, which results in detrusor muscle relaxation and urethral sphmcter confraction created by alpha-adrenergic stimulation. Voiding is consciously inhibited by voluntary contraction of striated urethral muscles and is reflexly inhibited by a spinal reflex, which tightens the external urethral sphincter when there is a sharp increase in intra-abdominal pressure (e.g., barking, coughing, sneezing, or retchmg).