THE ABDOMEN 897 



and vagina. On the summits of the rugae the columnar cells are 

 ciUated, but in the furrows between them they are devoid of 

 ciUa. The mucous membrane is freely provided with racemose 

 glands, which in the upper part of the cervix are lined with columnar 

 cells, and in the lower part with cubical cells. In both regions the 

 cells are non-cHiated. The glands in the lower part of the cer\'ix 

 have each a large lumen, and they secrete a very tenacious mucus 

 during pregnancy, which, in the later stages of that period, plugs 

 the OS externum. 



In addition to these glands clear vesicles of a yellowish colour, 

 called the ovula NabotM, may be seen in the mucous membrane 

 between the rugae of the arbor vitae uterina, which are supposed 

 to result from the closm-e of some of the racemose glands. 



Blood-supply. — ^The uterus is supphed with blood by the uterine 

 arteries, and the uterine branches of the ov^arfan arteries. 



Nerves. — ^The chief nerves are derived from the uterine sympa- 

 thetic plexus, which is an offshoot from the pehac plexus, and 

 accompanies the uterine artery. It is to be noted that the pelvic 

 plexus contains spinal fibres derived from the third and fourth 

 sacral nerves (sometimes also the second), and from the upper tsvo 

 or three Imnbar nerves, as in the case of the bladder and rectum. 

 The uterus also receives sympathetic fibres from the ovarian plexus, 

 which is derived from the renal and aortic plexuses. 



Lymphatics — Cervix Uteri. — The Iv-mphatic vessels of the cervix 

 have a threefold destination, namely, (i) the middle chain of the 

 external iliac glands, (2) the internal iliac glands, and (3) the inner 

 group of the common iliac glands. 



Body.— (i) The most of the lymphatics of the body of the uterus 

 join the h^nphatics of the ovary, and pass chiefly to the lateral 

 aortic glands, but a few terminate in the pre-aortic glands. (2) A 

 few lymphatics pass to the middle chain of the external iliac glands. 

 (3) Some l3TTiphatics accompany the round ligament of the uterus, 

 and terminate in the puhic group of the inguinal glands. 



The hinphatics of the cervix commimicate freely with those of 

 the body and with those of the upper part of the vagina. 



Structure of the Vagina. 



The wall of the vagina is composed of three coats — fibrous, mus- 

 cular, and mucous. 



The fibrous coat is composed of dense connective tissue. 



The muscular coat consists of plain muscular tissue, arranged as 

 an outer longitudinal and inner circular layer, both being closely con- 

 nected. Embedded in this coat there is a network of anastomosing 

 veins, representing erectile tissue, which is well developed round the 

 lower part of the passage. The plain muscular coat is replaced at 

 the external orifice by the striated sphincter vaginae muscle. 



The mucous membrane is covered by stratified squamous 

 epithelium, and is provided with papillae. In the upper part of 



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