The uterine tubes, also known as oviducts or fallopian tubes, are the female structures that transport the ova from the ovary to the uterus each month. In the presence of sperm and fertilization, the uterine tubes transport the fertilized egg to the uterus for implantation.
The uterine tubes are uterine appendages located bilaterally at the superior portion of the uterine cavity. These tubes exit the uterus through an area referred to as the cornua, forming a connection between the endometrial and peritoneal cavities. Each uterine tube is approximately 10 cm in length and 1 cm in diameter and is situated within the mesosalpinx. The mesosalpinx is a fold in the broad ligament. The distal portion of the uterine tube ends in an orientation encircling the ovary. The primary function of the uterine tubes is to transport sperm toward the egg, which is released by the ovary, and to then allow passage of the fertilized egg back to the uterus for implantation. 
A uterine tube contains 3 parts. The first segment, closest to the uterus, is called the isthmus. The second segment is the ampulla, which becomes more dilated in diameter and is the most common site for fertilization. The final segment, located farthest from the uterus, is the infundibulum. The infundibulum gives rise to the fimbriae, fingerlike projections that are responsible for picking up the egg released by the ovary.
The arterial supply to the uterine tubes is from branches of the uterine and ovarian arteries; these small vessels are located within the mesosalpinx.
The nerve supply to the uterine tubes is via both sympathetic and parasympathetic fibers. Sensory fibers run from thoracic segments 11-12 (T11-T12) and lumbar segment 1 (L1).
Both ultrasonography and hysterosalpingography can be useful in diagnosing uterine anomalies. 
Histologically, the uterine tubes are composed of 3 layers—the mucosa, muscularis, and serosa. The 3 different cell types within the mucosa of the uterine tubes include the columnar ciliated epithelial cells (25%), secretory cells (60%), and narrow peg cells (< 10%).
The mucosa has many folds, called plicae, which are most evident in the ampulla. The next layer is the muscularis, which is a layer of smooth muscle that surrounds the mucosa. The serosa is the outermost layer; it is primarily visceral peritoneum. 
Tubo-ovarian abscess and salpingitis
Tubo-ovarian abscess and salpingitis are infectious in nature and are typically associated with an ascending infection from the lower female pelvic organs (also known as pelvic inflammatory disease). These 2 conditions are often caused by infection with Neisseria gonorrhoeae or Chlamydia trachomatis, both of which are sexually transmitted, although other organisms may be involved. 
Females with salpingitis or tubo-ovarian abscess usually present with fever and acute onset of abdominal pain. The uterine tube in a patient with tubo-ovarian abscess commonly has pus within its walls (pyosalpinx). The diagnosis is made with ultrasonography, laboratory studies, and culture of the cervix or surgical specimen, if applicable.
Salpingitis and tubo-ovarian abscess are treated with intravenous antibiotics to cover common organisms that may have caused the ascending infection. Treatment is started before culture results are finalized. The goal of treatment is to resolve the symptoms and to maintain tubal function. (See also Pelvic Inflammatory Disease Empiric Therapy and Pelvic Inflammatory Disease Organism-Specific Therapy.) Surgery to remove the uterine tube is warranted in some cases, depending on the severity of infection.
Sequelae of these infections include infertility, chronic pain, and increased risk for ectopic pregnancy.
Hydrosalpinx occurs as an end stage of pyosalpinx, a disorder characterized by pus within the uterine tube.  Hydrosalpinx is the collection of sterile fluid within the tube secondary to occlusion of the tube (see above).
Ectopic pregnancy is caused by a fertilized ovum implanting either within the uterine tube or anywhere other than the endometrial cavity. In the circumstance of a tubal ectopic pregnancy, the lamina propria reacts like the endometrium and forms many decidual cells. [6, 7]
Because the lumen of the uterine tube is small, it cannot contain a growing pregnancy. Once the embryo or fetus becomes large enough, it can rupture through the wall of the uterine tube, becoming a medical emergency. Immediate surgical intervention is needed in this situation. If only one of the uterine tubes is removed, it is still possible for pregnancy to occur on the opposite side.
If the ectopic pregnancy is detected on ultrasonography before it becomes too advanced, medical treatment with methotrexate may be used in some cases.
Note the image below.