Ovulation every month means producing 1 egg. Ovulation is a complex process that relies heavily on the precise timing of hormone secretion from the reproductive system. Ovulation and conception can only occur when a series of subtle but crucial conditions are achieved within a fairly precise period of time. While understanding this process, infertile women must wonder how fertilization occurs.
For a newborn baby girl, the two ovaries already contain all the egg cells, or oocytes. During the fetal stage, the number of egg cells reaches several million, which decreases to less than 1 million at birth, and then continues to decrease. At menarche, an infertile woman may only have 250,000 eggs. From puberty to menopause, only 300 to 500 egg cells are actually excreted from the ovary, usually 1 per month, from the follicles on the surface of the ovary. When the reproductive years begin, the number of eggs a woman has is crucial. So far, medicine has not been able to determine the number of eggs in the ovaries at any one time.
When a girl enters the puberty period, the secretion of hormones in the body will accelerate, making ovulation and fertilization possible. The most important hormones include estrogen, progesterone, follicle-stimulating hormone, luteinizing hormone, and gonadotropin-releasing hormone.
Normal ovulation depends on a series of events triggered by signals from nerves in the brain. These signals are converted into hormone signals through the hypothalamus, a walnut-sized area of the brain, which secretes gonadotropin-releasing hormone every 60 to 90 minutes. Gonadotropin-releasing hormone stimulates the peripheral pituitary gland to secrete follicle-stimulating hormone and luteinizing hormone at a fixed time in the ovulation cycle. These two hormones are called gonadotropin-releasing hormones because they affect the gonads of both sexes—the ovaries and testicles.
In response to follicle hormone stimulation, several follicles (tiny, fluid-filled sacs in the ovaries, each containing an oocyte) expand, and the egg cell gradually matures, but only 1 One follicle takes advantage, making ovulation ultimately possible, which is why most people only have one child at a time. In the middle of the cycle, large amounts of luteinizing hormone accelerate the release of eggs from the largest follicles, and the eggs gather near the nearest fallopian tube. At this time, if healthy sperm are present, pregnancy can occur.
The formation of a cycle occurs once a month, but it requires a normally functioning hormone system, healthy ovaries and smooth fallopian tubes that can cultivate eggs.
The ovaries are the organs that produce eggs and secrete estrogen. The egg develops twice: once before birth and once after the onset of puberty. in embryoDuring this period, oogonia have entered the ovary and developed. At this time, the oogonia will continue to divide by meiosis (halving). There may be millions of cells like this at 7 months of gestational age. However, most of these cells will not mature, and some will even shrink in advance. Therefore, there are only 100,000 to 1 million left at birth. The egg continues to shrink from birth to the puberty period. If the egg is not fertilized after the puberty period begins, the egg cell will be excreted along with the proliferated endometrium and blood of the uterus. After menopause, the eggs are exhausted. A healthy woman will release 400 to 500 mature eggs in her lifetime, and most of the remaining oocytes have shrunk away. Therefore, the number of eggs in a woman is fixed.
The egg is larger than the sperm and has a protective membrane around it. The protective membrane consists of the zona pellucida and follicle cells. During a menstrual cycle, several or even a dozen follicles often develop simultaneously in the ovary, but generally only one develops into an egg.
Only 400 to 500 follicles develop into eggs in a woman\’s lifetime. As the follicles mature, part of the ovarian wall becomes particularly thin and appears particularly prominent. During ovulation, the follicle breaks out from here and enters the fallopian tube. The ovulation time is the 13th to 14th day from the first day of menstruation. Ovulation occurs once every 28 days.
After the egg is released from the ovary, it takes about 3 to 4 days to enter the uterus. Before entering the uterus, it should stay in the ampulla of the fallopian tube for 2 to 3 days. During sexual intercourse, after the sperm are ejaculated into the vagina, they move together into the uterine cavity and finally meet the egg in the fallopian tube. However, generally only one sperm enters the egg and becomes a fertilized egg. The fertilized egg implants in the uterine wall and gradually develops into a fetus.
This article is provided by Baidu Reading and is excerpted from \”The Clear \”Conception\” Plan\” Author: Sun Jianqiu Xie Yingbiao