Function of the Bladder and the Role of Pelvic Support

By Michelle Y. Morrill, MD, Director of Urogynecology at Kaiser San Francisco

Dr. Morrill has disclosed that she has no financial interests related to this topic.

In order to understand what has occurred when a woman has a pelvic floor disorder, such as incontinence or prolapse, it is useful to take a step back and examine the anatomy and normal function of pelvic organs. The pelvic bones provide a bony, solid frame for the pelvis like the rim of a bowl. The bottom of the bowl is made of the pelvic floor muscles – the muscles squeezed to do a Kegel exercise. Those muscles support the pelvic organs like the bladder, uterus, and rectum. Passing through the pelvic floor muscles in order from front to back are the urethra (the tube where urine comes out from the bladder), vagina, and anus. When the pelvic floor muscles contract they squeeze the urethra and anus closed.

If the pelvic floor muscles are damaged or weak, they do not support the pelvic organs, and these structures will stop functioning properly. If the urethra or anus cannot be squeezed closed tightly then they can leak or cause incontinence. If the uterus or the walls of the vagina are not well supported then they can relax down toward the opening of the vagina. This is called pelvic organ prolapse. Damage to the pelvic floor muscles occurs when the muscles are stretched or torn or when the nerves to these muscles are damaged. Factors that affect the risk of this happening are genetics, age, pregnancy and childbirth, obesity, chronic coughing, and neurologic diseases.


About the Author:

Dr. Michelle Morrill is director of Urogynecology at Kaiser San Francisco. She has particular interest in issues that concern improving the standards of urogynecologic care. Dr. Morrill has also published research on healthcare seeking and quality of life aspects of pelvic floor disorders.