ABSTRACT

This chapter summarizes clinical and experimental data to describe the complexity of the peripheral and central nervous systems controlling urine storage and elimination in the lower urinary tract. The urinary bladder and its outlet, the urethra, serve two main functions: storage of urine without leakage and periodic release of urine. Parasympathetic preganglionic neurons innervating the lower urinary tract are located in the lateral part of the sacral intermediate gray matter in a region termed sacral parasympathetic nucleus. Sympathetic outflow from the rostral lumbar spinal cord provides a noradrenergic excitatory and inhibitory input to the bladder and urethra to facilitate urine storage. The pelvic, hypogastric, and pudendal nerves also contain afferent axons that transmit information from the lower urinary tract to the lumbosacral spinal cord. The central pathways controlling lower urinary tract function are organized as on–off switching circuits that maintain a reciprocal relationship between the urinary bladder and urethral outlet.