The bladder´s duty is to collect the urine, produced by the kidneys, and to store it as long as it is wished for the concerned to void. The bladder wall consists of muscles, which are stretched by the increasing bladder content, which again causes after a certain filling degree an uriesthesis, i.e. the necessitiy to empty the bladder. The more the bladder is filled, the more acute is the urgency for evacuation.
The stimulus caused by the bladder muscles has to be led via the nervous system (I suppose that here it first of all concerns the vegetative nervous system) towards the brain, to produce at the concerned the conscious necessity to empty the bladder.
When man sleeps and his bladder is full, the filling stimulus must be so strong, that it is able to wake up the concerned. When the stimulus is too weak, the concerned does not wake up and when the bladder is filled furtheron, the bladder occlusion muscle is stretched and the bladder empties involuntarily.
The filling stimulus for a full bladder is the weaker, the heavier is the damage at the 3rd lumbar vertebra and the further vertebrae of the other functional circuits.
Now, the depth of children´s sleep is much more intensive than at grownups and older people, so that children need a stronger stimulus to wake up for urinating. Therefore the enuresis is in most of the cases a problem of the childhood.
The bladder belongs to the functional circuit bladder (L3 SMT®)/ kidneys ( Th10 SMT® and Th11 SMT®)/ teeth and ears (C3). However also damages at the kidney vertebrae and eventually even at the 3rd. cervical vertebra can be involved in bedwetting.
The problem worsens, when at older people at the same time an increasing tension in the bladder muscles happens, which decreases the capacity of the filling volume of the bladder. Such a tension of the muscles of the bladder wall is, how I already said, the more probable the older the concerned is (see chapter urinary and stress-incontinence).