How does the endometrium change during the proliferative phase?

For the majority of female friends, it is very necessary to understand the thickness of the proliferative endometrium. So what is the thickness of the proliferative endometrium? How does the endometrium change during the proliferative phase? Next, this article will introduce how the endometrium changes during the proliferative phase. Interested friends can take a look! Please see the detailed introduction below.

How does the endometrium change during the proliferative phase? With the cyclical changes in ovarian hormones, the endometrium also undergoes cyclical changes. The proliferative phase of the endometrium generally occurs between the 5th and 14th days of the menstrual cycle, which corresponds to the stage of follicular development and maturation. During menstruation, the endometrium is shed and gradually replaced by new growth. Around the 5th to 9th day of the cycle, under the action of estrogen secreted by the follicles, the endometrium is just repaired but is still thin. The glandular epithelium is cubic, with a round nucleus located at the bottom of the cell; the gland is loose, with a narrow and straight lumen; the interstitium is dense, with relatively straight and thin-walled arterioles growing toward the surface of the endometrium. Around the 10th to 14th day of the cycle, the endometrium gradually thickens to about 2 to 3 mm, the glands and interstitium both proliferate significantly, the number of glands increases, and the glandular cavities become larger and more curved. The glandular epithelial cells are tall columnar, with the nucleus moving from the bottom to the middle of the cell. The interstitium is dense, the cells change from spindle-shaped to star-shaped, the arterioles in the interstitium proliferate and elongate, curl in a spiral shape, and the lumen enlarges. Biochemical studies of the endometrium have found that estrogen prompts endometrial stromal cells to produce an acidic mucopolysaccharide, which is concentrated and polymerized to form the basic substance in the stroma, supporting the growth of the endometrium during the proliferative phase.

1. Early proliferative endometrium

On days 5-7 of the menstrual cycle. The proliferation and repair of the endometrium begins during the menstrual period. During this period, the endometrium is relatively thin, only 1-2 mm. Glandular epithelial cells are cuboidal or low columnar. The stroma is dense and the cells are star-shaped. The arterioles in the interstitium are straight and have thin walls.

2. Mid-stage proliferative endometrium

On the 8th to 10th day of the menstrual cycle. This stage is characterized by obvious interstitial edema; the number of glands increases, they grow, and they become curved; the glandular epithelial cells show active proliferation, the cells are columnar, and there is a division phase.

3. Late proliferative endometrium

On days 11-14 of the menstrual cycle. During this period, the endometrium thickens to 2-3 mm, and the surface is uneven and slightly wavy. The epithelial cells are tall columnar, the glandular epithelium continues to grow, the nuclear division phases increase, the gland becomes longer, and forms a curved shape. The interstitial cells are star-shaped and combined with each other to form a network; there is obvious edema in the tissue, the arterioles are slightly curved, and the lumen is enlarged.

The above is an introduction to how the endometrium changes during the proliferative phase. I believe that after reading the above introduction, you will have a certain understanding of the changes in the proliferative endometrium. From the above introduction, we can know that the endometrium thickens slowly during the proliferative phase, and this process repeats itself with the menstrual cycle. I hope that the introduction in this article will be helpful to friends who want to understand how the proliferative endometrium changes.