The entire process occurs over a period of several days.
Menstruation may be accompanied by a series of uterine contractions; these help expel the menstrual endometrium.
In humans, this will result in amenorrhea, or the absence of a menstrual period.
After menopause, the lining is often described as being atrophic.
Just over 100 of these genes are more specifically expressed in the endometrium with only a handfull genes being highly endometrium specific.
The corresponding specific proteins are expressed in the glandular and stromal cells of the endometrial mucosa.
During the menstrual cycle or estrous cycle, the endometrium grows to a thick, blood vessel-rich, glandular tissue layer.
This represents an optimal environment for the implantation of a blastocyst upon its arrival in the uterus.
The endometrium itself produces certain hormones at different stages of the cycle and this affects other parts of the reproductive system.
Certain specific proteins such as the estrogen receptor are also expressed in other types of female tissue types, such as the cervix, fallopian tubes, ovaries and breast.
Thin endometrium may be defined as an endometrial thickness of less than 8 mm. Treatments that can improve endometrial thickness include Vitamin E, L-arginine and sildenafil citrate.
These two layers occur only in endometrium lining the cavity of the uterus, not in the lining of the uterine (Fallopian) tubes: In the absence of progesterone, the arteries supplying blood to the functional layer constrict, so that cells in that layer become ischaemic and die, leading to menstruation.
It is possible to identify the phase of the menstrual cycle by reference to either the ovarian cycle or the uterine cycle by observing histological differences at each phase—for example in the ovarian cycle: The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity.The endometrium consists of a single layer of columnar epithelium plus the stroma on which it rests.