Human Anatomy - Kotsan I. Y. 2009

Urogenital apparatus
Genital organs - Female genital organs
Uterine tube

The uterine tube (tuba uterina), or Fallopian tube (tuba Fallopii), is a paired organ responsible for transporting the oocyte from the Ovary (from the peritoneal cavity) into the uterine cavity (Fig. 181). Located within the lesser pelvis cavity, the uterine tubes appear as cylindrical ducts (tubes) extending from the upper corners of the Uterus toward the ovary. Each tube lies along the upper margin of the broad ligament of the uterus, completely enveloped by the Peritoneum. Initially running horizontally, the tube reaches the wall of the lesser pelvis, arches around the ovary near its tubal extremity, and terminates near the Medial surface of the ovary. In a mature woman, the tube reaches a length of 10–12 cm, a width of 0.5 cm, and a lumen diameter of 2–4 mm.

The uterine tube consists of four parts: the uterine part, the isthmus, the ampulla, and the infundibulum. The uterine part (pars uterina) is embedded within the uterine wall. The ISTHMUS OF THE uterine tube (isthmus tubae uterinae) is the narrowest portion (2–3 mm), directly adjacent to the uterus. The ampulla of the uterine tube (ampulla tubae uterinae) follows the isthmus, accounting for nearly half of the entire tube's length. This section gradually increases in diameter and transitions into the next part, the infundibulum of the uterine tube (infundibulum tubae uterinae). The terminal margins of the infundibulum are irregular, featuring long, pointed projections known as the fimbriae of the tube (fimbriae tubae). One of these fimbriae is notably longer than the others; it reaches the ovary and attaches to it, hence termed the ovarian fimbria (fimbria ovarica). The ovarian fimbria guides the oocyte toward the infundibulum of the uterine tube.

The lumen of the uterine tube communicates at one end with the uterine cavity via a very narrow (up to 1 mm in diameter) uterine opening (ostium uterinum tubae), while opening at the other end via the abdominal opening (ostium abdominale tubae uterinae) into the peritoneal cavity. Thus, in females, the peritoneal cavity communicates with the external environment through the lumen of the uterine tubes, the uterine cavity, and the Vagina.

The wall of the uterine tube is composed of an outer serous coat (tunica serosa), supported by a subserous layer (tela subserosa); a middle muscular coat (tunica muscularis), consisting of two layers of smooth Muscle fibers (an outer longitudinal layer and an inner circular layer); and an inner mucous membrane (tunica mucosa), which forms numerous longitudinal tubal folds (plicae tubariae). The closer one gets to the abdominal opening of the uterine tube, the thicker the mucous membrane becomes, containing a greater number of folds, which are particularly abundant in the infundibulum. The mucous membrane is lined with simple ciliated columnar epithelium, whose cilia beat toward the uterus. Peristaltic contractions of the muscular coat, combined with the ciliary beating of the epithelial Cells, propel the oocyte toward the uterus. Fertilization of the oocyte takes place within the uterine tube. Inflammation of the uterine tubes can disrupt ciliary motility and cause tubal occlusion, which is a leading cause of Female Infertility.

Blood supply to the uterine tube is provided by Branches of the uterine and ovarian Arteries. Venous blood drains from the tube via corresponding Veins into the uterine venous plexus. Lymphatic vessels of the uterine tubes empty into the lumbar Lymph Nodes.

The uterine tube is innervated by branches of the ovarian and uterovaginal plexuses.