THE FEMALE GENERATIVE ORGANS 527 



The Innervation op the Uterus and Vagina and the 

 Mechanism op Uterine Contraction 



It is well known that the onset of parturition is manifested 

 by rhythmically repeated contractions of the uterus which 

 constitute the " labour pains." But although the contractions 

 are most pronounced at this period, observations on animals 

 have shown that even in a virgin uterus rhythmical movements 

 may occur. 



Kehrer ^ showed long ago that a uterus separated from the 

 body is capable of undergoing contractions if kept moist, and 

 at the normal body temperature. More recently Helme,^ 

 Kurdinowsld,^ Franz,* and others have confirmed Kehrer 's 

 observation, thus proving that the movements are not dependent 

 on impulses received from the central nervous system. Those 

 investigators showed that the excised uterus may undergo 

 regular contractions for a prolonged period if placed in a warm 

 bath of normal saline solution or on having its vessels perfused 

 with Locke's solution. According to Franz the excised virgin 

 uterus exhibits no spontaneous contractions, but Helme and 

 Kurdinowski state that they may occur, but that they are 

 much weaker than those taking place during and after pregnancy. 



The movements of the uterus have lately been more fuUy 

 investigated by Cushny,* who has carried out a large number of 

 experiments upon rabbits and other animals. This author 

 states that in virgins the unexcised uterus may remain motion- 

 less for a long time, but that after manipulation or exposure to 

 air rhythmic contractions are often developed. He is disposed 

 to beheve, therefore, that the virgin uterus in the intact animal 



^Kehrer, " Zusammenzlehungen der glatten Genitalmuskelatur," &c., 

 Beitrage zur Vergl, u. Exper. Geburtskunde, 1867. 



* Helme, " Contributions to the Physiology of the Uterus and the Phy- 

 siological Action of Drugs upon it," Reports of the Laboratory of the Royal 

 College of Physicians, Edinburgh, vol. iii., 1891. 



' Kurdinowski, " Physiologische und pharmakologische Versuche an der 

 isolirten Gebarmutter," Arch. f. Anat. u. Phys., phys. Abth. (supplement) 

 1904. 



* Franz, "Studien znr Physlologie des Uterus,'' Zeitschr. f. Qaburt. u. 

 Oyndk., vol. liii., 1904. 



'' Cushny, "On the Movements of the Uterus," Jour, of Phys., vol. xxxv. 

 1906. 



