The Urinary System

The different parts of the urinary system are the kidneys, ureters, bladder, and the urethra.

The function of the kidneys is to filter water and waste from the blood. They excrete urine, which passes through the ureters and then into the bladder. The bladder retains the urine until you are ready to pass it.

On the average, the kidneys excrete about 1 to 1-1/2 quarts of urine every 24 hours.

The bladder, a hollow and muscular organ varies in size, shape and position with age. Even the amount of urine stored changes with age. The bladder wall contains a smooth muscle called a detrusor muscle.

The urethra is a narrow tube that connects the bladder to an opening through where urine is excreted out of the body. Sphincter muscles surround the urethra. These muscles play a role in controlling the flow of urine from the body. These muscles also assist in holding urine in or even stopping it temporarily.

The bladder can hold 600 milliliters of urine (approximately 2 to 2½ cups). However, the urge to urinate occurs at half this amount. As the bladder starts to expand, the nerves in the bladder and surrounding areas send messages to the brain that the bladder is filling. These messages travel through the spinal cord. The brain responds by sending back the urge to urinate.

Of course, you normally choose when to urinate but once you’ve decided, your nervous system takes over and the urinary process becomes automatic. The detrusor contracts and the sphincters relax allowing urine to flow. Once the bladder has emptied out, the sphincters contract and the detrusor relaxes.

Of course, using the external sphincter, you can pause or control your urge to urinate and it will store in bladder. Nevertheless, the more kidneys secrete urine the urgency to relieve yourself (messages to the brain) become more urgent and the need to relieve oneself becomes more pressing.

Urinary incontinence affects men, women and children but is more common in elderly persons. Women have a slightly higher risk of developing incontinence when compared to men. Older men suffering from some type of prostate disease are also at risk. Urinary incontinence is treatable. If it cannot be cured, it can certainly be controlled or managed through supplements or through treatments prescribed by physicians.