A NEW THEORY OF MICTURITION AND URINARY CONTINENCE BASED ON HISTOMORPHOLOGICAL STUDIES .2. THE MUSCULUS SPHINCTER VESICAE - CONTINENCE OR SEXUAL FUNCTION

Results of a histomorphological study of serial sections carried out i n frontal, transversal and sagittal directions in 65 bladder necks are presented. It is shown that the trigonal system of the urinary bladde r consists of two anatomical structures: first, of a muscle originatin g from the muscle system of both ureters and converging to form within the bladder the interureteric ridge, the musculus interuretericus and of a second structure forming the actual trigonum vesicae. It is the musculus sphincter trigonalis or musculus sphincter vesicae. This musc le elliptically embraces the internal urethral orifice and is only for med by one muscle lamella. It does not as has often been described ext end in any form to the urethra or to the surroundings. The so-called B ell muscle does not exist. During the reproductive years the lower par t of the sphincter trigonalis is strongly pervaded with prostate tissu e. This could enable the muscle to have a double function: a continenc e function in accordance with a consequent distinction between the uri nary bladder and the urethra as urinary and sexual tract, and during e jaculation the muscle could prevent the retrograde ejaculation and on the other hand the contraction of the muscle could lead to the release of the prostate secretion.