smooth muscle contraction urinary tract smooth muscle contraction GO:0014848 A process in which force is generated within smooth muscle tissue, resulting in a change in muscle geometry. This process occurs in the urinary tract. Force generation involves a chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. The urinary tract consists of organs of the body that produce and discharge urine. These include the kidneys, ureters, bladder, and urethra.