Normal functioning of the uterus
Inside the uterus is the myometrium, a dense layer of large, elastic muscle cells that contract during a woman's normal menstrual cycle, generating the waves necessary for sperm to rise in search of the egg. If fertilization occurs, contractions help move the newly formed embryo into the uterus, where it implants in the endometrium, a tissue attached to the uterine muscle that specializes in nourishing the fetus.
During pregnancy, the myometrium increases greatly in size to accommodate the baby, and its contraction generates the force necessary to expel the baby during birth.
How does the uterus grow so much? Well, because it spreads throughout the myometrium Small round stem cells At rest, waiting for signals to activate. These signals come in the form of hormones, such as estrogen and progesterone, which stimulate them to divide and transform into large, elongated muscle cells, which promotes the growth of the uterus.
The transformation occurs in several stages, so that each dividing stem cell generates two cells, one of which remains the stem cell. The other goes through several stages until it becomes a muscle cell. This preserves stem cell reserves in the myometrium.
In the event of infertility, myometrial contractions are also necessary to eliminate the lining of the uterus, which is exactly what happens with each menstrual cycle with vaginal bleeding.
