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The egg cell is the female gamete, i.e. the female reproductive cell. It is formed in the ovaries and reaches a size of 200 microns.
Structure and function of the ovum
The primary and only function the ovum it is involved in the fertilization process, i.e. the connection of the female (egg) and male (sperm) gametes. Unfertilized ovum it dies and is eliminated from the body. If fertilization occurs, ovum it nestles in the uterus, where the embryo develops, and then the fetus.
The ovum it matures in the ovaries and is released at the time of ovulation, i.e. 13-15 days before the first day of your next period.
Each has matured ovum it contains the genetic material needed for the development of the embryo and then the fetus.
The ovum it is surrounded by a so-called radiant wreath made of cells that produce a cytoplasmic matrix containing, inter alia, glycosaminoglycans (including hyaluronic acid). From the radiant wreath it stretches around the ovum transparent sheath, which contains receptors that react to the presence of sperm and acts as a protective barrier that allows it to get inside the ovum only one sperm. Otherwise (if to the ovum more than one sperm has penetrated) polyspermia could occur.
Egg cells they mature in the ovaries before the girl’s 20th week of fetal life. The embryonic gonads with which a girl is born may contain up to tens of millions ova – however, most of them die in adolescence, while those that tightly cover the granular cells remain. It is in them that cell division takes place. Ripe ovarian follicles are called Graaf’s follicles. Approximately 13-15 days before the next period, the Graaf follicle ruptures and is released the ovum into the peritoneal cavity, i.e. ovulation (ovulation). The ovum it is caught by the fallopian tube and travels to the uterine cavity.
If fertilization fails, ovum it dies and is eliminated from the woman’s body.
How long does an egg live?
Life time the ovum is an average of 24 hours. Therefore, it lives much shorter than sperm, which can survive in a woman’s body for up to several days. However, when fertilization occurs, ovum it does not die and after about 7-10 days it implantes in the uterus.
Although ovum lives only 24 hours after release, fertilization can occur up to 5 days before ovulation. This is because sperm cells are much more viable and can survive in a woman’s genital tract for several days after intercourse.
Life time the ovum and her ability to fertilize depends on the woman’s way of life. Factors that significantly reduce the chances of fertilization are stress, stimulants (cigarettes, alcohol, psychoactive substances), fatigue, improper diet and an unhealthy lifestyle.
Egg cells however, they can be frozen, which extends their life and ability to fertilize. Female gametes are frozen in liquid nitrogen – they retain their biological functions and are not susceptible to the passage of time. This solution is useful for cancer patients and for women who want to postpone their motherhood.
What is the number of eggs?
Girls are born with a fixed amount ovathat develop around the 5th month of gestation. Number ova at the time of the girl’s birth, it is 2 million. Egg cells are enclosed in the ovarian follicles and divided equally between the two ovaries. During the entire life of a woman, about 500 matured are released ova. Along with each menstrual cycle, the amount ova fertilization capacity decreases.
Girls are born with a certain number of ready-made ova. How many of them will mature and how long a woman will be fertile depends on genetic conditions and on her lifestyle.
Egg cells they mature and are released under the action of the oocyte maturation inhibitor (OMI). Not everyone ovum however, it will be released – over the years they age in the same way as the entire female body and sometimes degenerate or even die.
Interesting facts about the ovum
The ovum it is the largest cell in the human body. It is about 0,12 mm in diameter, 4 times the size of a skin cell, 26 times the size of a red blood cell, and 20 times the size of a sperm.
The ovum attracts the sperm to itself due to progesterone, i.e. the female sex hormone. It acts as a decoy, stimulates sperm and makes them move faster and more efficiently to the female gamete. The action of this hormone causes the sperm whips to become more mobile – the egg therefore navigates the sperm and makes it easier for it to penetrate inside.
Scientists have found that drinking 5 cups of coffee a day is effective in weakening egg cells and reduces the chance of fertilization.