In Children
Urination, or voiding, is a complex activity. The bladder is a balloonlike muscle that lies in the lowest part of the abdomen. The bladder stores urine, then releases it through the urethra, the canal that carries urine to the outside of the body. Controlling this activity involves nerves, muscles, the spinal cord and the brain.
The bladder is made of two types of muscles: the detrusor, a muscular sac that stores urine and squeezes to empty, and the sphincter, a circular group of muscles at the bottom or neck of the bladder that automatically stay contracted to hold the urine in and automatically relax when the detrusor contracts to let the urine into the urethra. A third group of muscles below the bladder (pelvic floor muscles) can contract to keep urine back.
A baby's bladder fills to a set point, then automatically contracts and empties. As the child gets older, the nervous system develops. The child's brain begins to get messages from the filling bladder and begins to send messages to the bladder to keep it from automatically emptying until the child decides it is the time and place to void.
Failures in this control mechanism result in incontinence. Reasons for this failure range from the simple to the complex.
Incontinence happens less often after age 5: About 10 percent of 5-year-olds, 5 percent of 10-year-olds, and 1 percent of 18-year-olds experience episodes of incontinence. It is twice as common in girls as in boys.
Read more about this topic: Urinary Incontinence
Famous quotes containing the word children:
“I taught school in the early days of my manhood and I think I know something about mothers. There is a thread of aspiration that runs strong in them. It is the fiber that has formed the most unselfish creatures who inhabit this earth. They want three things only; for their children to be fed, to be healthy, and to make the most of themselves.”
—Lyndon Baines Johnson (1908–1973)
“The sturdy Irish arms that do the work are of more worth than oak or maple. Methinks I could look with equanimity upon a long street of Irish cabins, and pigs and children reveling in the genial Concord dirt; and I should still find my Walden Wood and Fair Haven in their tanned and happy faces.”
—Henry David Thoreau (1817–1862)