Fallopian tube

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Fallopian Tubes
Scheme female reproductive system-en.svg
Schematic frontal view of female anatomy
Gray589.png
Vessels of the uterus and its appendages, rear view. (Fallopian tubes visible at top right and top left.)
LatinTuba uterina (Greek: Salpinx)
Gray'ssubject #267 1257
Arterytubal branches of ovarian artery, tubal branch of uterine artery via mesosalpinx
Lymphlumbar lymph nodes
PrecursorMüllerian duct
MeSHFallopian+Tubes
 
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Fallopian Tubes
Scheme female reproductive system-en.svg
Schematic frontal view of female anatomy
Gray589.png
Vessels of the uterus and its appendages, rear view. (Fallopian tubes visible at top right and top left.)
LatinTuba uterina (Greek: Salpinx)
Gray'ssubject #267 1257
Arterytubal branches of ovarian artery, tubal branch of uterine artery via mesosalpinx
Lymphlumbar lymph nodes
PrecursorMüllerian duct
MeSHFallopian+Tubes

The Fallopian tubes, also known as oviducts, uterine tubes, and salpinges (singular salpinx) are two very fine tubes lined with ciliated epithelia, leading from the ovaries of female mammals into the uterus, via the utero-tubal junction. In non-mammalian vertebrates, the equivalent structures are the oviducts.

Anatomy[edit source | edit]

In a woman's body the tube allows passage of the egg from the ovary to the uterus. Its different segments are (lateral to medial): the infundibulum with its associated fimbriae near the ovary, the ampullary region that represents the major portion of the lateral tube, the isthmus which is the narrower part of the tube that links to the uterus, and the interstitial (also intramural) part that transverses the uterine musculature. The tubal ostium is the point where the tubal canal meets the peritoneal cavity, while the uterine opening of the Fallopian tube is the entrance into the uterine cavity, the utero-tubal junction.

Histology[edit source | edit]

A cross section of fallopian tube shows four distinct layers: Serosa, subserosa, lamina propria and innermost mucosal layer. The serosa is derived from visceral peritoneum. Subserosa is composed of loose adventitious tissue, blood vessels, lymphatics, an outer longitudinal and inner circular smooth muscle coats. This layer is responsible for peristaltic action of fallopian tube. Lamina propria is a vascular connective tissue.[1] There are two types of cells within the simple columnar epithelium of the Fallopian tube (oviduct). Ciliated cells predominate throughout the tube, but are most numerous in the infundibulum and ampulla. Estrogen increases the production of cilia on these cells. Interspersed between the ciliated cells are peg cells, which contain apical granules and produce the tubular fluid. This fluid contains nutrients for spermatozoa, oocytes, and zygotes. The secretions also promote capacitation of the sperm by removing glycoproteins and other molecules from the plasma membrane of the sperm. Progesterone increases the number of peg cells, while estrogen increases their height and secretory activity. Tubal fluid flows against the action of the ciliae, that is toward the fimbrial end.

In view of longitudinal variation in histological features of tube, the isthmus has thick muscular coat and simple mucosal folds; whereas ampulla has complex mucosal folds.[1][clarification needed]

Attachments[edit source | edit]

Medially, fallopian tubes are attached to uterine cornua. Laterally, they are attached to broad ligament by mesosalpinx and also to lateral pelvic wall.[1]

Function in fertilization[edit source | edit]

When an ovum is developing in an ovary, it is encapsulated in a sac known as an ovarian follicle. On maturity of the ovum, the follicle and the ovary's wall rupture, allowing the ovum to escape. The egg is caught by the fimbriated end and travels to the ampulla where typically the sperm are met and fertilization occurs; the fertilized ovum, now a zygote, travels towards the uterus aided by activity of tubal cilia and activity of the tubal muscle. After about five days the new embryo enters the uterine cavity and implants about a day later.

The release of a mature egg does not alternate between the two ovaries and seems to be random. After removal of an ovary, the remaining one produces an egg every month.[2]

Occasionally the embryo implants into the Fallopian tube instead of the uterus, creating an ectopic pregnancy, commonly known as a "tubal pregnancy".

Patency testing[edit source | edit]

While a full testing of tubal functions in patients with infertility is not possible, testing of tubal patency is important as tubal obstruction is a major cause of infertility. A hysterosalpingogram, laparoscopy and dye, or HyCoSy will demonstrate that tubes are open. Tubal insufflation is a standard procedure for testing patency. During surgery the condition of the tubes may be inspected and a dye such as methylene blue can be injected into the uterus and shown to pass through the tubes when the cervix is occluded. As tubal disease is often related to Chlamydia infection, testing for Chlamydia antibodies has become a cost-effective screening device for tubal pathology.[3]

Fallopian tube

Embryology and homology[edit source | edit]

Embryos have two pairs of ducts to let gametes out of the body; one pair (the Müllerian ducts) develops in females into the Fallopian tubes, uterus and vagina, while the other pair (the Wolffian ducts) develops in males into the epididymis and vas deferens.

Normally, only one of the pairs of tubes will develop while the other regresses and disappears in utero.

The homologous organ in the male is the rudimentary appendix testis.

Pathology[edit source | edit]

Salpingitis is inflammation of the Fallopian tubes and may be found alone, or be a component of pelvic inflammatory disease (PID). Saccular dilation of the fallopian tube at its narrow portion, due to inflammation, is known as salpingitis isthmica nodosa. Like PID and endometriosis, it may lead to Fallopian tube obstruction. Fallopian tube obstruction is associated with infertility and ectopic pregnancy.

Fallopian tube cancer, which typically arises from the epithelial lining of the Fallopian tube, has historically been considered to be a very rare malignancy. Recent evidence suggests it probably represents a significant portion of what has been classified as ovarian cancer in the past.[4] While tubal cancers may be misdiagnosed as ovarian cancer, it is of little consequence as the treatment of both ovarian and Fallopian tube cancer is similar.

Surgery[edit source | edit]

The surgical removal of a Fallopian tube is called a salpingectomy. To remove both sides is a bilateral salpingectomy. An operation that combines the removal of a Fallopian tube with removal of at least one ovary is a salpingo-oophorectomy. An operation to restore a fallopian tube obstruction is called a tuboplasty.

Etymology and nomenclature[edit source | edit]

They are named after their discoverer, the 16th century Italian anatomist, Gabriele Falloppio.

Though the name 'Fallopian tube' is eponymous, some texts spell it with a lower case 'f' from the assumption that the adjective 'fallopian' has been absorbed into modern English as the de facto name for the structure.

The Greek word salpinx (σαλπιγξ) means "trumpet".

Additional images[edit source | edit]

See also[edit source | edit]

References[edit source | edit]

  1. ^ a b c Daftary, Shirish; Chakravarti, Sudip (2011). Manual of Obstetrics, 3rd Edition. Elsevier. pp. 1-16. ISBN 9788131225561.
  2. ^ "Menstrual Cycle: Biology of the Female Reproductive System: Merck Manual Home Health Handbook". Merck.com. Retrieved 2011-03-06. 
  3. ^ Kodaman PH, Arici A, Seli E. (June 2004). "Evidence-based diagnosis and management of tubal factor infertility.". Curr Opin Obstet Gynecol. 2004 Jun;16(3):221-9. 16 (3): 221–9. PMID 15129051. 
  4. ^ Hirst, JE.; Gard, GB.; McIllroy, K.; Nevell, D.; Field, M. (Jul 2009). "High rates of occult fallopian tube cancer diagnosed at prophylactic bilateral salpingo-oophorectomy.". Int J Gynecol Cancer 19 (5): 826–9. doi:10.1111/IGC.0b013e3181a1b5dc. PMID 19574767. 

External links[edit source | edit]