Control of Urinary Drainage and Voiding

摘要: Urine differs greatly in ion and solute composition from plasma contains harmful noxious substances that must be stored for hours then eliminated when it is socially convenient to do so. The urinary tract handles this output composed of a series pressurizable muscular compartments separated by sphincteric structures. With neural input, these structures coordinate the delivery, collection, and, ultimately, expulsion urine. Despite large osmotic chemical gradients waste fluid, bladder maintains highly impermeable surface face physically demanding biomechanical environment, which mandates recurring cycles area expansion increased wall tension during filling, followed rapid compression voiding. Afferent neuronal inflow mucosa submucosa communicates sensory information about fullness, voiding initiated consciously through coordinated central spinal efferent outflow detrusor, trigonal internal sphincter, external urethral sphincter after periods relative quiescence. Provocative new findings suggest some cases, lower symptoms, such as incontinence, urgency, frequency, overactivity, pain may viewed consequence urothelial defects (either barrier breakdown or inappropriate signaling cells underlying afferents potentially interstitial cells). This review describes physiologic anatomic mechanisms urine moved kidney bladder, stored, released. Relevant clinical examples dysfunction are also discussed.