[Anatomo-physiological aspects of the lower urinary tract in men and modifications related to ageing]. / Aspects anatomo-physiologiques de l'appareil vésico-sphinctérien chez l'homme et modifications liées au vieillissement.

ABSTRACT

MICTURITION AND INCONTINENCE The lower urinary tract, composed of several organs necessary for micturition, is controlled by the encephalic and peripheral centres, which have a synergic effect and coordinate the lower urinary tract. Continence is ensured by the effect of the adrenergic sympathetic nerve that increases urethral sphincter tonus and maintains low pressure in the bladder during filling. Micturition appeals to the cholinergic system mediated by the muscarinic receptors situated in the bladder. AGEING OF THE PROSTATE Under the influence of dihydrotestosterone and growth factors, ageing of the prostate is characterized by histological modifications leading to hypertrophy, obstructing the flow of urine. AGEING OF THE BLADDER Electronic microscopy studies have shown the presence of degenerative lesions and, on urodynamic level, are characterised by over or under-activity. Ageing of the peripheral and central nervous centres is morphological and metabolic with the production of vascular and free radicals, involving the systems that control micturition and continence. The ageing kidney has a tendency to produce more urine at night because of the functional changes that intervene in the salt and water balance regulation systems.