Coordinated activities between bladder, urethra, pelvic muscles and surrounding connective tissues.
Urine storage under voluntary control and modulated by the pontine micturition center.
The bladder is compliant through the range of physiological bladder filling, up to 500-600 ml and accommodates increasing urinary volume without increasing the pressure in the bladder.
The distension of the bladder related to detrusor smooth muscle and neurologic modulation.
Infants empty their bladder when fullness prompts detrusor contraction and with bladder training children respond to sensation of urge at volumes of 2-300 ml and void at appropriate time.