Uterine glands or endometrial glands are tubular glands, lined by a simple columnar epithelium, found in the functional layer of the

endometrium The endometrium is the inner epithelium, epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The funct ...

that lines 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 ...

. Their appearance varies during the

menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that makes pregnancy possible. The ovarian cycle controls the production and release of eg ...

. During the proliferative phase, uterine glands appear long due to estrogen secretion by the ovaries. During the secretory phase, the uterine glands become very coiled with wide lumens and produce a glycogen-rich secretion known as ''histotroph'' or ''uterine milk''. This change corresponds with an increase in blood flow to spiral arteries due to increased

progesterone Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...

secretion from the

corpus luteum The corpus luteum (Latin for "yellow body"; : corpora lutea) is a temporary endocrine structure in female ovaries involved in the production of relatively high levels of progesterone, and moderate levels of estradiol, and inhibin A. It is the ...

. During the pre-menstrual phase, progesterone secretion decreases as the corpus luteum degenerates, which results in decreased blood flow to the spiral arteries. The functional layer of the uterus containing the glands becomes necrotic, and eventually sloughs off during the menstrual phase of the cycle. They are of small size in the unimpregnated uterus, but shortly after impregnation become enlarged and elongated, presenting a contorted or waved appearance.

Function

Feto-maternal interface showing uterine milk

Hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

s produced in early

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

stimulate the uterine glands to secrete a number of substances to give nutrition and protection to the embryo and fetus, and the

fetal membranes The fetal membranes are the four extraembryonic membranes, associated with the developing embryo, and fetus in humans and other mammals. They are the amnion, chorion, allantois, and yolk sac. The amnion and the chorion are the chorioamniotic ...

. These secretions are known as histiotroph, alternatively histotroph, and also as uterine milk. Important uterine milk proteins are glycodelin-A, and

osteopontin Osteopontin (OPN), also known as bone /sialoprotein I (BSP-1 or BNSP), early T-lymphocyte activation (ETA-1), secreted phosphoprotein 1 (SPP1), 2ar and Rickettsia resistance (Ric), is a protein that in humans is encoded by the ''SPP1'' gene (sec ...

. Some secretory components from the uterine glands are taken up by the secondary yolk sac lining the exocoelomic cavity during pregnancy, and may thereby assist in providing fetal nutrition.

Additional images

File:Gray36.png, Primary chorionic villi. Diagrammatic. File:Gray37.png, Secondary chorionic villi. Diagrammatic.

References

External links

* * * - "Mammal, uterus (LM, Medium)" * {{DEFAULTSORT:Uterine Glands Uterus Human female endocrine system