Incontinence Help (continued)

Urinary incontinence is the inability to control urination. It may be temporary or permanent and can result from a variety of problems in the urinary tract. Urinary incontinence is generally divided into four groups according to the malfunction involved:

• Stress Incontinence
• Urge Incontinence
• Overflow Incontinence
• Functional Incontinence

Often, more than one type of incontinence is present. Approximately 40% of all incontinence cases fall into more than one of the four categories. A variety of disease and medical problems may contribute to each of the four major types of incontinence. Because incontinence is a symptom rather than a distinct disease, it is often difficult to determine a definite cause.

Normal Urination

The urinary system helps to maintain proper water and salt balance throughout the body:

The process of urination begins in the two kidneys, which process fluids and dissolved waste matter to produce urine.

Urine flows out of the kidneys into the bladder through two long tubes called ureters.

The bladder is a sac that acts as a reservoir for urine. It is covered with a membrane and enclosed in a powerful muscle called the detrusor. The bladder rests on top of the pelvic floor . This is a muscular structure similar to a sling running between the pubic bone in front to the base of the spine.

The bladder stores the urine until it is eliminated from the body via a tube called the urethra, which is the lowest part of the urinary tract. (In men it is enclosed in the penis. In women it leads directly out.)

The connection between the bladder and the urethra is called the bladder neck . Strong muscles called sphincter muscles encircle the bladder neck (the smooth internal sphincter muscles ) and urethra (the fibrous external sphincter muscles ).

The Process of Urination

The process of urination is a combination of automatic and conscious muscle actions. There are two phases: the emptying phase and the filling and storage phase. The Filling and Storage Phase. When a person has completed urination, the bladder is empty. This triggers the filling and storage phase, which includes both automatic and conscious actions.

The Automatic Actions. An automatic signaling process in the brain uses a pathway of nerve cells and chemical messengers (neurotransmitters) called the cholinergic and adrenergic systems. The brain signals the detrusor muscle , which surrounds the bladder, to relax. As the muscles relax, the bladder expands and allows urine to flow into it from the kidney. As the bladder fills to its capacity (about 8 to 16 oz of fluid) the nerves in the bladder send back signals of fullness to the spinal cord and the brain.

The Conscious Actions. As the bladder swells, the person becomes conscious of a sensation of fullness. In response, the individual holds the urine back by voluntarily contracting the external sphincter muscles (the muscle group surrounding the urethra). (These are the muscles that children learn to control during the toilet training process.)

When the need to urinate overcomes the conscious holding back, then urination (the emptying phase) begins. The Emptying Phase. The process of urination also involves automatic and conscious actions.

The Automatic Actions. At the point when a person is ready to urinate, the nervous system initiates the voiding reflex. In this case, the nerves in spinal cord (not the brain) trigger the event. These nerves signal the detrusor muscles around the bladder to contract. At the same time, nerves are also signaling the involuntary internal sphincter (a strong muscle encircling the bladder neck) to relax. With the bladder muscles squeezing and its neck open, the urine flows out of the bladder into the urethra.

The Conscious Actions. Once the urine enters the urethra a person consciously relaxes the external sphincter muscles, which allows urine to pass out.

Urine is then completely drained from the bladder and the process of filling and storing begins again.