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
mammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s into the
uterusThe uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
, via the utero-tubal junction. In non-mammalian vertebrates, the equivalent structures are the
oviductIn non-mammalian vertebrates, the passageway from the ovaries to the outside of the body is known as the oviduct. The eggs travel along the oviduct. These eggs will either be fertilized by sperm to become a zygote, or will degenerate in the body...
s.
Anatomy and histology
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
infundibulumThe third part of the uterine tube is the infundibulum. It terminates with the ostium of Fallopian tube, surrounded by fimbriae, one of which is attached to the ovary. Together, the infundibulum and fimbria find the oocyte after ovulation.-External links: - "The Female Pelvis: The Oviduct"...
with its associated
fimbriaeIn the female reproductive system, the fimbria is a fringe of tissue around the ostium of the Fallopian tube, in the direction of the ovary....
near the ovary, the
ampullaryThe ampulla is the second portion of the uterine tube. It is an intermediate dilated portion, which curves over the ovary.It is the most common site of human fertilization.The word ampulla is from Latin for flask....
region that represents the major portion of the lateral tube, the
isthmusThe visible medial third of the uterine tube is the isthmus tubae uterinae. It is medidally bordered by the intramural portion of the tube that connects to the endometrial cavity and laterally by the ampullary part of the tube....
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 ostiumThe ostium of the Fallopian tube may refer to the proximal or distal opening of the tube.The proximal tubal opening is located within the uterus at the uterotubal junction and accessible via hysteroscopy...
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.
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
infundibulumAn infundibulum is a funnel-shaped cavity or organ.* Lungs: The alveolar sacs of the lungs from which the air chambers open are called infundibula...
and
ampullaAn ampulla was, in Ancient Rome, a "small nearly globular flask or bottle, with two handles" . The word is used of these in archaeology, and of later flasks, often handle-less and much flatter, for holy water or holy oil in the Middle Ages....
.
EstrogenEstrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
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
capacitationCapacitation is the penultimate step in the maturation of mammalian spermatozoa and is required to render them competent to fertilize an oocyte.This step is a biochemical event; the sperm move normally and look mature prior to capacitation....
of the sperm by removing
glycoproteinGlycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...
s and other molecules from the plasma membrane of the sperm.
ProgesteroneProgesterone also known as P4 is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species...
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 fimbrated end.
Function in fertilization
When an
ovumAn ovum is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization...
is developing in an ovary, it is encapsulated in a sac known as an
ovarian follicleOvarian follicles are the basic units of female reproductive biology, each of which is composed of roughly spherical aggregations of cells found in the ovary. They contain a single oocyte . These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single...
. On maturity of the ovum, the follicle and the ovary's wall rupture, allowing the
ovum to escapeOvulation is the process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum . Ovulation also occurs in the estrous cycle of other female mammals, which differs in many fundamental ways from the menstrual cycle...
. 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
zygoteA zygote , or zygocyte, is the initial cell formed when two gamete cells are joined by means of sexual reproduction. In multicellular organisms, it is the earliest developmental stage of the embryo...
, travels towards the uterus aided by activity of tubal cilia and activity of the tubal muscle. After about five days the new
embryoAn embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
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.
Occasionally the embryo implants into the Fallopian tube instead of the
uterusThe uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
, creating an
ectopic pregnancyAn ectopic pregnancy, or eccysis , is a complication of pregnancy in which the embryo implants outside the uterine cavity. With rare exceptions, ectopic pregnancies are not viable. Furthermore, they are dangerous for the parent, since internal haemorrhage is a life threatening complication...
, commonly known as a "tubal pregnancy".
Patency testing
While a full testing of tubal functions in patients with
infertilityInfertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...
is not possible, testing of tubal patency is important as tubal obstruction is a major cause of infertility. A hysterosalpingogram will demonstrate that tubes are open when the radio-opaque dye spills into the uterine cavity. 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 blueMethylene blue is a heterocyclic aromatic chemical compound with the molecular formula C16H18N3SCl. It has many uses in a range of different fields, such as biology and chemistry. At room temperature it appears as a solid, odorless, dark green powder, that yields a blue solution when dissolved in...
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 antibodiesChlamydia antibodies are antibodies targeting bacteria of the Chlamydia genus, but it generally refers specifically to antibodies targeting Chlamydia trachomatis, which is the cause of Chlamydia infection in humans.-Usage:...
has become a cost-effective screening device for tubal pathology.
Embryology and homology
EmbryoAn embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s have
two pairs of ducts to let
gameteA gamete is a cell that fuses with another cell during fertilization in organisms that reproduce sexually...
s out of the body; one pair (the
Müllerian ductMüllerian ducts are paired ducts of the embryo that run down the lateral sides of the urogenital ridge and terminate at the Müllerian eminence in the primitive urogenital sinus. In the female, they will develop to form the Fallopian tubes, uterus, cervix, and the upper two-third of the vagina; in...
s) develops in females into the Fallopian tubes, uterus and
vaginaThe vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...
, while the other pair (the
Wolffian ductThe mesonephric duct is a paired organ found in mammals including humans during embryogenesis....
s) develops in males into the
epididymisThe epididymis is part of the male reproductive system and is present in all male amniotes. It is a narrow, tightly-coiled tube connecting the efferent ducts from the rear of each testicle to its vas deferens. A similar, but probably non-homologous, structure is found in cartilaginous...
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 testisThe appendix testis is a vestigial remnant of the Müllerian duct, present on the upper pole of the testis and attached to the tunica vaginalis. It is present about 90% of the time.-Clinical significance:...
.
Pathology
Pelvic inflammatory diseasePelvic inflammatory disease is a generic term for inflammation of the uterus, fallopian tubes, and/or ovaries as it progresses to scar formation with adhesions to nearby tissues and organs. This may lead to infections. PID is a vague term and can refer to viral, fungal, parasitic, though most...
can strike the fallopian tubes. This might cause a
Fallopian tube obstructionFallopian tube obstruction is a major cause of female infertility. Blocked fallopian tubes are unable to let the ovum and the sperm converge, thus making fertilization impossible. Fallopian Tubes are also known as oviducts, uterine tubes, and salpinges .-Types:About 20% of female infertility can be...
.
Fallopian tube cancerPrimary fallopian tube cancer , often just tubal cancer, is a malignant neoplasm that originates from the fallopian tube.-Frequency:...
is a rare neoplasm that can arise from the epithelial lining of the Fallopian tube. This cancer is sometimes misdiagnosed as ovarian cancer. However, treatment of both ovarian and Fallopian tube cancer is similar.
Surgery
The surgical removal of a Fallopian tube is called a
salpingectomySalpingectomy refers to the surgical removal of a Fallopian tube.-Indications:The procedure was first performed by Lawson Tait in patients with a bleeding ectopic pregnancy; this procedure has since saved the lives of countless women...
. 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
tuboplastyA tuboplasty is a surgical operation to correct a fallopian tube obstruction or adhesion, to achieve a pregnancy in women with tubal infertility. Thus, it is a form of assisted reproductive technology.-Techniques:...
.
Etymology and nomenclature
They are named after their discoverer, the 16th century
ItalianItaly , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
anatomist,
Gabriele FalloppioGabriele Falloppio , often known by his Latin name Fallopius, was one of the most important anatomists and physicians of the sixteenth century....
.
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
GreekAncient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
word
salpinxA salpinx was a trumpet-like instrument of the ancient Greeks. -Construction:The salpinx consisted of a straight, narrow bronze tube with a mouthpiece of bone and a bell of variable shape and size; extant descriptions describe conical, bulb-like, and spherical structures...
(σαλπιγξ) means "
trumpetThe trumpet is the musical instrument with the highest register in the brass family. Trumpets are among the oldest musical instruments, dating back to at least 1500 BCE. They are played by blowing air through closed lips, producing a "buzzing" sound which starts a standing wave vibration in the air...
".
External links