STBUCTURE OF THE UTERUS. 985 



and are thinnest at the entrances of the Fallopian tubes. The tissue is 

 very dense : it is composed of bundles of muscular fibres of the plain 

 variety, of small size in the unimpregnated uterus, interlacing with each 

 other, but disposed ia bands and layers, intermixed with much fibro-areolar 

 tissue, a large number of blood-vessels and lymphatics, and some nerves. 

 The areolar tissue is more abundant near the outer surface. The arrange- 

 ment of the muscular fibres is best studied in the uterus at the full period 

 of gestation, in which the bands and layers formed by them become aug- 

 mented in size, and much more distinctly developed. They may be referred 

 to three sets or orders, viz., external, internal, and intermediate. Those of 

 the external set are arranged partly in a thin superficial sheet, immediately 

 beneath the peritoneum, and partly in bands and incomplete strata, situated 

 more deeply. A large share of these fibres arch transversely over the 

 fundus and adjoining part of the body of the organ, and converge at either 

 side towards the commencement of the round ligaments, along which they 

 are prolonged to the groin. Others pass off in like manner to the Fallopian 

 tubes, and strong transverse bands from the anterior and posterior surfaces 

 are extended into the ovarian ligaments. A considerable number of thinly 

 scattered fibres also pass at each side into the duplicature of the broad 

 ligament, and others are described as running back from the cervix of the 

 uterus into the recto-uterine folds or plicae semilunares. The fibres of the 

 subperitoneal layer are much mixed with areolar tissue, especially about 

 the middle of the anterior and posterior surfaces of the uterus, in which 

 situation many of the super6cial fibres appear to have as it were a median 

 attachment from which they diverge. The fibres on the inner surface of 

 the uterus are disposed with comparative regularity in its upper part, being 

 arranged there in numerous concentric rings round the openings of the 

 two Fallopian tubes, the outermost and largest circles of the two series 

 meeting from opposite sides in the middle of the uterus. Towards the 

 cervix the internal fibres run more transversely ; elsewhere they take 

 various directions. The intermediate fibres, between the external and 

 internal set, pass in bands among the blood-vessels, following less regular 

 courses. 



The mucous membrane which lines the uterus is thin and closely adherent 

 to the subjacent substance, especially in the body of the organ. It is con- 

 tinued from the vagina, and into the Fallopian tubes. Between the rugsa 

 of the cervix, already described, it is provided with numerous mucous 

 follicles and glands. There are also occasionally found in the same situa- 

 tion certain small transparent vesicular bodies, which, from an erroneous 

 opinion as to their nature, were named the ovula Nabothi. They appear 

 to be closed and obstructed mucous follicles, distended with a clear viscous 

 fluid. In the inferior third or half of the cervix, the mucous membrane 

 presents papillae covered with ciliated epithelium. 



In the body of the uterus the mucous membrane is thin, smooth, soft, 

 and of a reddish-white colour. When viewed with a magnifying lens, it is 

 found to be marked with minute dots, which are the orifices of nume- 

 rous simple tubular glands, somewhat like those of the intestine. Some 

 of these tubular glands are branched, and others are slightly twisted into 

 a coil. These glands can be distinctly seen in the unimpregnated and in 

 the virgin uterus, but they become enlarged and more conspicuous after im- 

 pregnation (fig. 686). The epithelium is columnar and ciliated. 



Ligaments of the uterus. Where the peritoneum is reflected from the 

 uterus to the bladder in front, and to the rectum behind, it forms, in each 



