THE UTEEUS 415 



entirely wanting at frequent intervals. The outer layer is usually 

 broadest at the free margin of the oviduct and at its opposite side 

 where the tube is attached to the broad ligament. The inner cir- 

 cular fibres are more or less obliquely disposed, and, toward the 

 mucosa, the muscular bundles fuse insensibly with the cellular 

 connective tissue of the mucous membrane. 



The serous coat of the oviduct is continuous with the perito- 

 neum. It consists of an outermost layer of endothelium which 

 rests upon a subepithelial layer of connective tissue, by which it is 

 firmly united to the muscular wall. This portion of the serous 

 coat contains the larger vessels and nerves, which are distributed 

 to the inner coats. 



Blood Supply. The arteries of the oviduct are derived from 

 the uterine and ovarian vessels. The larger divisions find their 

 way through the connective tissue of the serosa whence they send 

 smaller branches inward to form a plexus between the layers of the 

 muscular wall and among the bundles of circular muscle fibres. 

 From this plexus capillaries are distributed to the muscular coat, 

 and to the mucous membrane in which they form a rich subepithe- 

 lial capillary plexus. The veins follow a similar course, and like 

 the arteries, form an extensive plexus in the muscular coat. The 

 abundance of vessels in the muscular wall of the oviduct has 

 led to the description of this coat as the vascular layer of the 

 organ. 



The lymphatics arise by anastomosing plexuses in the mucosa, 

 from which vessels pass to the serous coat and enter valved lym- 

 phatics by which the lymph is conveyed to the lymphatic nodes 

 of the lumbar region. 



The nerves are distributed from a plexus in the serous coat, to 

 the muscular wall, and to the mucosa, in which they form a ter- 

 minal subepithelial plexus. 



THE UTEKUS 



The wall of the uterus consists of a mucous membrane, a mus- 

 cular coat, and an outermost serous coat which is derived from the 

 peritoneum and invests the body of the organ. The cervix uteri 

 projects into the vaginal canal and the serous coat is there replaced 

 by a reflection of the vaginal mucosa. 



The serous coat of the uterus consists of endothelium which 

 rests upon a thin subepithelial layer of connective tissue. It pre- 

 sents no peculiarities. 



