The uterotubal junction is the connection between the endometrial cavity of the

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

and the

fallopian tube The fallopian tubes, also known as uterine tubes, oviducts or salpinges (: salpinx), are paired tubular sex organs in the human female body that stretch from the Ovary, ovaries to the uterus. The fallopian tubes are part of the female reproduct ...

(uterine tube) at the proximal tubal opening, the beginning of the intramural part of the fallopian tube. Histologically, the endometrial

epithelium Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

changes over to

cilia The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike proj ...

ted tubal epithelium.

Function

Patency of the uterotubal junction is necessary for normal reproduction. The tubes can get blocked here by infection ( salpingitis) and surgical intervention may be necessary. Mouse studies have indicated that selective passage of individual

spermatozoa A spermatozoon (; also spelled spermatozoön; : spermatozoa; ) is a motile sperm cell (biology), cell produced by male animals relying on internal fertilization. A spermatozoon is a moving form of the ploidy, haploid cell (biology), cell that is ...

may occur at this junction, with abnormal morphology being identified as a significant selection criterion, leading to predominantly normal

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

passing towards the ovum. Absence of the protein calmegin has also been suggested as a critical factor for reliable sperm passage.

Other

The uterotubal junction is accessible by hysteroscopy and the entry point for tubal cannulation and falloposcopy. Contraceptive methods have been developed to block the uterotubal junction.

References

Pelvis Uterus {{human-repro-stub