UTERUS (FUNCTIONS). 



large quantities in every instance of a healthy 

 menstrual flux. 



Source of the menstrual fluid. The vagina, 

 the os and cervix, and the body of the uterus, 

 have been severally regarded as the parts 

 which furnish the menstrual flux. And so 

 far as the mucous element is concerned it is 

 probable that all these surfaces contribute a 

 certain proportion ; but that the blood in nor- 

 mal menstruation is derived mainly from the 

 lining membrane of the body of the uterus, is 

 placed almost beyond doubt by the following 

 considerations : 



1. In the uterus of one who has died whilst 

 menstruating, a remarkable difference is usu- 

 ally perceptible in the condition of the mu- 

 cous membrane lining the cavity of the body 

 and cervix respectively. That of the body is 

 highly injected, of a deep red colour, the ves- 

 sels distinct, and the capillaries numerous. 

 That of the cervix exhibits a condition the 

 opposite of this. It is pale, uninjected, and 

 free from all appearance of distended vessels. 



2. If such a uterus be injected, the same 

 conditions are observed in a more marked 

 degree. All the capillaries on the mucous 

 membrane of the body are filled, but compa- 

 ratively few of the cervix ; an abrupt line 

 of demarcation occurring sometimes at the 

 internal os uteri. 



3. If gentle pressure be employed, as by 

 taking the uterus in the palm of the hand, 

 and slightly approximating the two sides, 

 blood is perceived to flow up from the little 

 pores or orifices of the utricular glands, which 

 are everywhere perceptible, upon the surface 

 of the mucous membrane, until this collects in 

 the cavity in a quantity sufficient to cover the 

 surface. 



4. If the same experiment be made under 

 water, in a dish or shallow basin, with the 

 aid of very gentle pressure on the sides of the 

 uterus, such as could not apparently cause 

 any rupture of uterine vessels, the little 

 streamlets of blood are seen welling up from 

 each pore, and mingling with the water. In 

 neither of these cases is the blood seen to 

 proceed from any part of the cervix, but only 

 from the lining membrane of the uterine 

 cavity. 



5. The blood, in ordinary menstruation, is 

 seen to flow from the os uteri into the specu- 

 lum, but is never observed to proceed from 

 the lips of the cervix, except the latter be in 

 an abnormal state.* 



6. The cavity of the uterus, after death 

 during menstruation, has been frequently 

 found to contain blood or a coagulum. 



From these observations it may be con- 

 cluded, that in normal menstruation the blood 

 is furnished by the walls of the uterine cavity. 

 Whether the lining membrane of the oviducts 

 also contributes any portion of the fluid is not 

 certainly known. But I have had reason to 

 think this very probable, from observing that, in 

 cases of death during menstruation, the tubes 

 as well as the uterus contained blood, which 



* Whitehead, loc. cit. p. 24. 



665 



may in some cases, however, have entered them 

 by regurgitation from the latter. (See also p. 

 618.) 



By what means does the blood escape from 

 the uterine vessels in healthy menstruation ? 

 The investigation of this question is attended 

 by great difficulties, and data sufficient even 

 for its approximate determination are, yet 

 wanting. 



The explanations which have been offered 

 are chiefly the following : 



(a.) The blood is supposed to escape in 

 the form of a secretion. 



So long as it was maintained that the men- 

 strual fluid differed essentially from pure 

 blood, the view that it was eliminated from 

 the general circulating current by a process 

 analogous to that which obtains in true secret- 

 ing glands received ready acceptance, and the 

 menstrual fluid was, in accordance with such 

 views, denominated a secretion. But since it 

 is now known with tolerable accuracy to what 

 portion alone of the menstrual fluid the term 

 secretion can, with any degree of truth, be 

 applied, it seems useless further to argue the 

 question of secretion or non-secretion, in 

 reference to the main ingredient of this fluid, 

 which has already been shown to be pure 

 blood, unaltered in its physical and chemical 

 constituents, until after it has become mixed 

 with other and adventitious matters. 



(6.) The blood is supposed to escape by 

 transudation through the capillaries of the 

 uterine mucous membrane. 



This view, which is proposed by Coste * 

 and others, need not be considered specially 

 with reference to the uterus. Those who 

 think that the blood-corpuscles, which mi- 

 croscopic examination proves to be abun- 

 dantly present in the menstrual fluid, can pass 

 by transudation, unaltered and entire, through 

 the w r alls of capillary or other vessels without 

 rupture of their coats, will find no difficulty 

 in applying this explanation to the production 

 of a like phenomenon, as it may be supposed 

 to occur in the uterus. 



(c.) The blood is supposed to escape 

 through lacerated capillary vessels. 



Many observed facts give to this view a cer- 

 tain amount of probability. Thus, in an in- 

 jected uterus the capillary vessels, which form 

 so fine a network upon its inner surface 

 (fig. 439.), may be occasionally observed de- 

 nuded, and hanging forth in detached loops. 

 In such a condition I have found the vessels 

 when death has occurred during menstrua- 

 tion.f Unless this is a post-mortem change, 

 which is improbable, it may be assumed that 

 this laying bare of the capillaries is the conse- 

 quence of a vital action, whereby a portion of 

 the epithelial and mucous surfaces are broken 



* Histoire da Developpement, torn, prem., 1 fasc. 

 p. 209. 1847. 



f I am not prepared to assert that this condition 

 is always present during menstruation, or that it is 

 limited to such periods. A larger number of ex- 

 amples than those in which I have observed this 

 feature would be necessary to establish such a fact ; 

 and the whole subject requires a closer examination 

 than has yet been given to it. 



