FALLOPIAN TUBE OR OVIDUCT (NORMAL ANATOMY). 



599 



termed the middle wing. The Fallopian 

 tube occupies the entire upper border of this 

 wing, and receives from it a complete perito- 

 neal investment, except along the lower bor- 

 der or line of junction of the two surfaces of 

 membrane composing it, at which line the ves- 

 sels and nerves enter. Thus the tube resembles 

 an intestine in the mode of its investment, 

 but with this difference, that the peritoneal 

 coat is more loosely applied, especially in 

 young subjects ; where the convolutions of 

 the tube are more distinctly marked, and lie 

 free within the sheath, which does not follow 

 their windings (fig. 4-18.).* 



The tubal mesentery (fig. 404. /) is tri- 

 angular, or somewhat falciform in shape. Its 

 narrow pointed end is directed towards the 

 uterus, where the tube has scarcely any ca- 

 pacity for independent motion ; but as the 

 depth of the mesentery increases outwardly 



greater freedom of movement is permitted. 

 The greatest breadth of the mesentery is 

 found at a distance of two thirds of its 

 length from the uterine extremity, and here 

 it measures 1". From this point a slight 

 narrowing occurs, and the membrane ter- 

 minates in an abrupt margin \\" in length, 

 which extends from the lower border of the 

 mouth of the tube to the bulbous extremity 

 of the ovary. 



This border, which is thickened by the 

 addition of a layer of mucous membrane de- 

 rived from the mouth of the Fallopian tube, 

 constitutes the tubo-ovarian ligament (fig. 

 404. rf). 



Separate parts and divisions. The full ex- 

 tent of the Fallopian tube cannot be ascer- 

 tained until the entire canal, in its interior, 

 has been laid open. The tube which, ex- 

 ternally viewed, appears to spring from the 



Fig. 405. 



Right. Fallopian tube laid open. From an adult who had not borne children. (After Richard.') 



a, funnel-shaped canal leading from the uterus to b, uterine portion of the tube; c, point at which the 

 large plicse commence ; d, infundibulum covered by plicae, continuous with those lining the canal ; e, tubo- 

 ovarian ligament and fringes ; /, ovary ; g, round ligament. 



superior angle of the uterus, is thus seen to 

 commence by a small orifice, ostium uterinum, 

 upon the inner surface of the uterus. This 

 orifice conducts to a narrow canal (Jigs. 

 405. b and 406.) which, after traversing the 

 walls of the organ, and constituting the pars 

 itterina, expands into a gradually widening 

 tube (fig. 405. c), whose form nearly cor- 

 responds with the external configuration 

 of the part. Towards the extremity of this 

 canal, a sudden contraction occurs, consti- 

 tuting the external orifice of the tube, ostium 

 abdominnle (fig. 404. c). But this does not 

 form the termination of the oviduct, for the 

 latter immediately widens into the trumpet- 

 like orifice (infundibulum), whose margin, 

 split up into numerous fringed processes, 



* For a further account of the reflections of 

 peritoneum, which enclose the uterine appendages 

 .see "Ligaments of the Uterus," in this article. 



(fimbrice), (fig. 404. a a) give to that part 

 the torn and jagged appearance suggestive 

 of the idea that it has been bitten or torn, 

 as expressed in the name, morsus diaboli, 

 applied by ancient writers to this part. Each 

 of these parts exhibit peculiarities of struc- 

 ture, requiring a special description. 



Internal, or uterine orifice, ostium uterinum. 

 This orifice, which ought to be regarded 

 as marking the termination rather than the 

 commencement of the tube, is found at the 

 extremity of a short, funnel-shaped conduit, 

 (fig. 405. a) which leads from the general 

 cavity of the uterus into the upper and outer 

 angle on either side of that organ. Here, 

 while 1 there is no abrupt line of demarcation 

 to indicate the point of commencement of the 

 canal, the characteristic structure of the 

 uterine mucous membrane gradually ceases. 

 The peculiar arrangement of its capillary 

 vessels and the orifices of the uterine glands, 

 U u 4 



