Fallopian tube anatomy

The bilateral fallopian tubes are a pair of long, thin and curved muscular tubes in women, 10 to 12 cm long and 5 mm in diameter. They are located on both sides of the fundus of the uterus and are encapsulated in the inner edge of the platysma tendon of the uterus. The two horns of the uterus extend to the left and right ovaries, forming the channels that transport eggs into the uterus.

Shape construction:

Each bilateral fallopian tube is divided into four parts: the interstitial space, isthmus, ampulla and Brunner's infundibulum. The interstitial part is included in the muscle of the uterus. The lumen is initially inclined upward and outward. The length of the section is 0.8 to 2 cm, and the diameter of the lumen is 0.5 to 1.0 mm. The muscle wall is the posterior side of the bilateral fallopian tubes, narrow, straight and strong. It connects to the opening of the uterus, called the bilateral fallopian tube cervical opening. That is, the narrow part close to the uterus, with a lumen diameter of 2 to 3 mm. Then it slowly expands to the wider part on both sides, namely the ampulla; the diameter of the ampulla is 5 to 8 mm, which is the front side of the bilateral fallopian tubes connected to the Burkholderia funnel, with thin and curved walls; the Burkholderia funnel is a large Burkholderia-shaped funnel developed at the front end, and the crack-shaped edge of the Burkholderia funnel is called an umbrella. There are bilateral abdominal openings of the fallopian tubes in the shallow layer of the Burkholderia funnel.

Except for the interstitial part, part of the fallopian tubes on both sides are covered by the retroperitoneum, which is connected to the inner edge of the broad tendon; except for the adhesion of the mesosalpinx on both sides, it is completely surrounded by the retroperitoneum, and the umbrella-shaped end opens into the abdomen. Its convex part (i.e., the uterine and ovarian umbrella) is more prominent than other parts; it forms a shallow groove, approaching or reaching the uterus and ovaries.

The muscle tissue of the bilateral fallopian tubes is generally divided into two layers, namely the circular inner layer and the longitudinal surface layer. Distally on the tube, the double layer becomes less distinct and is replaced at the fimbria by an interlaced network of muscle fibers. The muscle tissue of the fallopian tubes on both sides often contracts rhythmically, and the shrinkage rate varies with the menstrual cycle. The largest shrinkage and strength occur during egg transfer, but are weaker and slower during pregnancy; the lining of the fallopian tubes is covered with mucosa, and its epithelial cell line is composed of unilateral columnar cells. Because the lumen has no submucosal layer, the mucosal layer is in direct contact with the muscularis; the mucosa is arranged into vertical folds, which become more complex at the fimbriae. Therefore, the surface of each section of the lumen is different. The cross section of the uterine part of the bilateral fallopian tubes shows four simple folds, forming a pattern similar to the Maltese cross (X); the folds of the isthmus are more complex; in the ampulla, its cavity is almost completely occupied by a tree-like structure showing the different sizes of each segment of the bilateral fallopian tube lumen, longitudinal folds and the associated mucosa of the bilateral fallopian tubes with the bilateral mesosalpinx, uterine horns and uterine ovaries. The fluidity caused by the microvilli on both sides of the fallopian tube is directed toward the uterus, and its peristalsis is an important factor in transporting eggs.

Organizational Structure:

In terms of tissue structure, it has rich and colorful elastic tissue, blood vessels and lymphatic vessels. The tissue changes that occur in the bilateral fallopian tube mucosa during the physiological cycle are similar to those of the uterine wall, but not as obvious as those of the uterine wall. During the follicular stage, squamous epithelial cells are longer, wider with microvilli, and the cytoplasm is close to the edge; those without microvilli are narrow, and the cytoplasm is closer to the substrate; during the follicular stage, metabolic cells are larger, taller than microvilli cells, and their nuclei are squeezed out; during the physiological stage, the above changes are more prominent. After menopause, its mucosal characteristics. The squamous epithelial cells are short and grow rapidly. The reason for the change is due to the change in the ratio of estrogen and pro-estrogen secreted by the uterus and ovaries.