UTERUS (NORMAL ANATOMY). 



623 



extent, dilate, for the purpose of allowing the 

 ovum to pass, just as the os uteri dilates at 

 the time of labour. 



UTERUS. 

 NORMAL ANATOMY. 



(Syn. Womb, Mother, Eng. ; 



, Gr. : Uterus, Matrix, Lat. ; Utcro, 

 \ta\.; Matrice, Fr. ; Barmutter, Geb'drmutter, 

 Fruchthulter, Germ. ; Baarmoeder, Lijfmoe- 

 dcr, Dutch.) 



The uterus is that segment of the genera- 

 tive track which lies between the lower ex- 

 tremities of the Fallopian tabes and the fornix 

 or upper end of the vagina. In man it is 

 normally formed by the complete coalescence 

 of the two uterine cornua, which in most 

 of the mammalia remain more or less distinct 

 constituting the bicorned or divided uterus. 

 These, in man and the quadrumana, unite to 

 form a single symmetrical organ, serving for 

 the passage of the seminal fluid, and for the 

 reception, protection, nutrition, and final ex- 

 pulsion of the mature ovum. 



The uterus is not altogether peculiar to the 

 female. Like the mammary gland, it has its 

 representative in the male, though only in a 

 rudimental state. The existence of such a 

 rudimentary organ is more easily shown in 

 the male of many mammalian animals than 

 in man, in whom, perhaps, it is the least 

 conspicuous, and where its presence, as a type 

 of structure, can only be proved by a close 

 study of homologies, and by the aid of those 

 occasional exemplifications of the true rela- 

 tions of this part which the comparatively 

 rare occurrence of hermaphrodite forms 

 affords. 



Situation and position. The unimpregnated 

 uterus is situated entirely within the pelvis, 

 where it lies deep among the other pelvic con- 

 tents, with many of which it is in immediate 

 relation ; the bladder lying anteriorly, the 

 rectum posteriorly, the ovaries and Fallopian 

 tubes laterally, the small intestines supe- 

 riorly, and the vagina and perineum inferiorly 

 with regard to it. These several parts, aided 

 by the broad and round ligaments, serve to 

 support the uterus and maintain it in its natu- 

 ral position. But this position will of neces- 

 sity vary according to the condition of the 

 neighbouring organs, and in some degree also 

 with the varying postures of the body. 



The nature and degree of the variations in 

 regard to situation and position of which the 

 uterus is susceptible will be more easily 

 understood after the ligaments and other con- 

 nections by which these movements are re- 

 strained have been described. At present it 

 will be only necessary to observe that the mo- 

 tions of the uterus are restricted chiefly to 

 three directions. First, the broad ligaments, 

 which maintain the organ nearly in the median 

 line, permit by their laxity a slight deviation 

 towards either side. Secondly, a certain 

 amount of ascent and descent is allowed by 

 the structures which attach the uterus to the 



lower part of the pelvis. But the former of 

 these movements will be limited by the utero- 

 sacral ligaments, and the weight or pressure 

 of the superincumbent viscera ; and the latter 

 also especially by the same ligaments, and to 

 a certain extent by the support derived from 

 the posterior wall of the vagina and the parts 

 which close the pelvis below. Thirdly, the 

 uterus enjoys a certain range of motion in the 

 direction of a line drawn from pubes to sacrum 

 in order to accommodate it to the state of 

 fulness or emptiness of the adjacent viscera. 

 For when the bladder is full and the rectum 

 empty, the uterus will be carried nearer to the 

 sacrum ; and conversely, with an empty blad- 

 der and a distended rectum, the position of 

 the uterus will be proportionately nearer to 

 the pubes ; and these alterations of position 

 will be constantly and daily repeated. 



But an equal degree of mobility does not 

 belong to every part of the uterus ; for while 

 the movement of the cervix is limited by the 

 attachment of the vagina and utero-sacral 

 ligaments, the fundus is left entirely free to 

 follow the alternate fillings and emptyings of 

 the bladder. Thus a movement of nutation 

 will result, the fundus uteri approaching the 

 pubes and sacrum alternately ; and this is 

 probably the greatest range of motion of which 

 any portion of the uterus is normally suscep- 

 tible. 



But allowing for these variations, there will 

 still be an average position which the uterus 

 occupies in the pelvis, and this may be as- 

 sumed to occur at the time when the bladder 

 and rectum are both moderately distended. 



Under these circumstances, the position of 

 the uterus relatively to surrounding parts will 

 be in accordance with the accompanying sec- 

 tional diagram (fg. 423.), representing the 



Fig. 423. 



Sectional diagram to show the normal position of the 

 uterus in the pelvis. 



pelvic contents. Here A represents the ute- 

 rus, B the bladder, and c the rectum, both of 

 the latter being moderately distended. 



