Menstruation is a monthly occurrence for almost all sexually mature females. Menstruation occurs when the uterus sheds the endometrium (inner nutrition rich mucous membrane of the uterus) in the absence of pregnancy. It happens in women from puberty (between age 11to 15) to menopause (between age 45-50.)
Here is a brief description of the four stages that the endometrium undergoes during Menstruation. The animation graphically represents this process. (The myometrium is a layer of the uterus that consists of uterine myocytes).
Stage of Menses (Days 1-4)
Also known as the bleeding phase, menses is caused due the withdrawal of the ovarian hormones – oestrogen and progesterone at the end of the ovarian cycle. Normal bleeding consists of dead endometrial cells, blood, vaginal cells, mucous from the cervix and other necrotic tissues. Most women bleed for 3 to 5 days.
Stage of Repair (Days 4-6)
Post the menstrual bleeding, for a short duration of about 48 hours the endometrium rests and repairs itself. The endometrium is disorganized and about 1mm thick during this stage.
Stage of Proliferation (Days 6-16)
As estrogen gets produced in the ovary, the endometrium proliferates. It increases in size and thickness. New blood vessels grow from the stumps of the old vessels. Endometrial glands grow bigger although their number remains the same. At the end of the proliferative stage, the endometrium is about 2-3 mm thick.
Women who are being treated to cure infertility undergo ultrasonography to measure the endometrial thickness.
Stage of Secretion (Days 16-28)
Once ovulation occurs, progesterone produced in the ovary increases and the endometrium continues to grow to reach a thickness of around 5-7 mm. Women undergoing ultrasound treatment for Infertility tend to have thickness up to 10 -15mm.
The endometrial glands begin to secrete in this stage, due to which it’s called the stage of secretion. Initially, the secretions get collected in the cells of the glands but towards the last few days of this stage, the secretions are pushed out of the cells and get collected in the endometrial cavity.
Endometrial growth stops from the 22nd day of the cycle as the corpus luteum (the essential lining that grows waiting to nourish a healthy pregnancy) degenerates. Eventually it begins to shrink, after which shedding of the endometrial lining occurs. Thus starts the next menstrual cycle.
Here is a brief description of the four stages that the endometrium undergoes during Menstruation. The animation graphically represents this process. (The myometrium is a layer of the uterus that consists of uterine myocytes).
Stage of Menses (Days 1-4)
Also known as the bleeding phase, menses is caused due the withdrawal of the ovarian hormones – oestrogen and progesterone at the end of the ovarian cycle. Normal bleeding consists of dead endometrial cells, blood, vaginal cells, mucous from the cervix and other necrotic tissues. Most women bleed for 3 to 5 days.
Stage of Repair (Days 4-6)
Post the menstrual bleeding, for a short duration of about 48 hours the endometrium rests and repairs itself. The endometrium is disorganized and about 1mm thick during this stage.
Stage of Proliferation (Days 6-16)
As estrogen gets produced in the ovary, the endometrium proliferates. It increases in size and thickness. New blood vessels grow from the stumps of the old vessels. Endometrial glands grow bigger although their number remains the same. At the end of the proliferative stage, the endometrium is about 2-3 mm thick.
Women who are being treated to cure infertility undergo ultrasonography to measure the endometrial thickness.
Stage of Secretion (Days 16-28)
Once ovulation occurs, progesterone produced in the ovary increases and the endometrium continues to grow to reach a thickness of around 5-7 mm. Women undergoing ultrasound treatment for Infertility tend to have thickness up to 10 -15mm.
The endometrial glands begin to secrete in this stage, due to which it’s called the stage of secretion. Initially, the secretions get collected in the cells of the glands but towards the last few days of this stage, the secretions are pushed out of the cells and get collected in the endometrial cavity.
Endometrial growth stops from the 22nd day of the cycle as the corpus luteum (the essential lining that grows waiting to nourish a healthy pregnancy) degenerates. Eventually it begins to shrink, after which shedding of the endometrial lining occurs. Thus starts the next menstrual cycle.
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