Normally bladder muscle contracts under neurogenic control from the brain, through afferent nerve impulses fired from the spinal center for urination. It causes muscles to contract the bladder to throw urine out of the body through urethra, with simultaneous relaxation of the external urinary sphincter, so that urine flows out without any resistance.
In certain diseases, this co-ordinated muscular function of the bladder is deranged, resulting in ineffective voiding of urine. Common derangements include:
Over Active Bladder (OAB): This condition causes premature contraction of the urinary bladder muscles, before it is adequately distended to it’s physiological capacity.It results in marked frequency of urination, with urgency, occasionally resulting in leakage of urination.
Infection of the bladder ( Cystitis): In presence of infection, the bladder muscle contracts much earlier than adequate distension is achieved, due to irritation of the epithelium. Fortunately, this settles down spontaneously with treatment of cystitis.
Neurogenic Bladder: In these conditions, the muscular actions of the bladder are deranged in variable ways, depending on the type of neurogenic dysfunction. As mentioned earlier, for efficient voiding of urine, neurogenic innervation of bladder and it’s functional integrity is extremely vital.
A number of clinical conditions may adversely affect this delicate balance, resulting in either ineffective storage, ineffective voiding or variable combination of both.
Common examples of such clinical conditions include congenital spinal deformities, central nervous dysfunction, spinal trauma or compression, diseases of peripheral nervous system, commonest being diabetic neuropathy.