The Uterine or Fallopian Tubes

The uterine or Fallopian tubes (Tubæ uterinæ) act as excretory ducts of the ovaries, since they convey the ova from the reproductive glands to the uterus. They are not, however, in direct continuity with the glands, but rather partly in contiguity with, and partly attached to, them. They are two flexuous tubes, about ten to twelve inches (ca. 25 to 30 cm.) long, which extend from the extremities of the uterine cornua to the ovaries. Each is inclosed in a peritoneal fold, derived from the external layer of the broad ligament, and termed the mesosalpinx. This largely covers the outer aspect of the ovary, and forms with it and the broad ligament a pouch called the bursa ovarica. The uterine extremity of the tube communicates with the cavity of the cornu by a minute orifice, the ostium uterinum. The ovarian or fimbriated extremity is expanded into a funnel-shaped infundibulum. The margin of the latter is slit into irregular processes or fimbriæ, some of which, the fimbriæ ovaricæ, are attached in the ovulation fossa. In the center of the fimbriated extremity is a small opening, the ostium abdominale, by which the tube communicates with the peritoneal cavity. The tube appears normally to be applied to the ovary, so that the extruded ova pass into it and are conveyed to the uterus.

Pedunculated cysts, the hydatids of Morgagni, are often found on one or more of the fimbriæ. In the mesosalpinx are blind flexuous tubules, which constitute the paroöphoron, a remnant of the Wolffian body. They are most evident in the young adult, and tend to disappear with increasing age. Not uncommonly they give rise to cysts.

Structure.—The tube is covered externally by a serous coat formed by the mesosalpinx. The serous membrane is continued on the fimbriæ, and meets the mucous lining on them. The fibrous coat or adventitia is continuous with the fibrous lamina of the broad ligament. The muscular coat consists chiefly of circular fibers, although longitudinal fibers occur externally. The mucous coat is thin and is much plicated. The folds (Plicæ tubariæ) are chiefly longitudinal, but in the wide part of the tube (Ampullæ tubæ) they are very complex, so that on cross-sections the spaces between the folds may be mistaken for branched tubular glands. The folds are continued on to the fimbriæ. The epithelium is a single layer of columnar ciliated cells, the cilia producing a current directed toward the uterus. At the fimbriated extremity this epithelium passes gradually into the squamous type of the serous coat.

Vessels and Nerves.—The arteries are derived from the utero-ovarian artery. The veins are satellites of the arteries. The lymphatics pass with the ovarian vessels to the lumbar glands. The nerves have a similar origin to those of the ovary.