ABSTRACT
The functions of the lower urinary tract to store and periodically release urine are dependent upon neural circuitry in the brain and spinal cord. This dependence on central nervous control distinguishes the lower urinary tract from many other visceral organs that maintain a certain level of activity even after the elimination of extrinsic neural input. The lower urinary tract is also unusual in regard to the complexity of its neural regulation. For example, micturition depends on the integration of autonomic and somatic efferent mechanisms within the lumbosacral spinal cord. This is necessary to coordinate the activity of visceral organs (the bladder and urethra) with that of urethral striated muscles. In addition, micturition is under voluntary control and depends upon learned behavior that develops during maturation of the nervous system, whereas many other visceral functions are regulated involuntarily. This chapter will review the peripheral and central neural mechanisms controlling the lower urinary tract.
