Egg and sperm

The egg and spermatozoon are two cells, at the confluence of which the future person will begin to develop. They possess unique genetic information that determines not only the gender of a person, but also his appearance, character, state of health and much more. The moment of the beginning of a new human life always causes interest.

What is the difference between an egg and a sperm?

Eggs are formed in the body of a woman even at the stage of embryo development, she is born with 400 thousand eggs, of which only 200-400 will mature and leave the ovary in her entire life, depending on the number of menstrual cycles. The female ovum is the largest cell in the body, it has the size of a poppy seed, and in the Petri dish it can be seen with the naked eye. It has an even round shape, inside it is the cytoplasm and nucleus. In addition, immediately after leaving the ovary, it is surrounded by a dense layer of epithelium, which will gradually be rejected as the egg passes through the fallopian tube. The egg can not move independently.

Spermatozoon is a small cell. It looks like a tadpole, has a large head, which in shape can be round or conical, and a small tail. As a result of sexual intercourse, a woman gets to several hundred million spermatozoa in the woman's uterus, but only one, the strongest and fastest, will be able to fertilize an egg, which will be near the ripe cell earlier than others. The sperm carries the genetic information of the father, which will be transferred to the offspring, almost 40% of it consists of DNA structures that determine the characteristics of your baby. Spermatozoa move very fast, in an hour they can overcome a distance of two centimeters.

Where does the fertilization take place?

The egg and spermatozoon are found, as a rule, in the fallopian tubes, which connect the uterus and the ovary with each other. Spermatozoa fall into the fallopian tubes from the vagina, and they fill both tubes, and the egg leaves only one of the ovaries. Within a few hours, the egg will be fertilized and begin its journey back to the uterus through the sinuous fallopian tubes. This way will take the cell to several days.

During this time, two cells will actively share, forming the future baby, its main organs. 7-10 days after fertilization, the cell will adhere to the epithelium, which is lined with the uterine cavity, and from it begins to form an embryo and amniotic fluid that gradually fills the whole space of the uterus and becomes a placenta that feeds the baby right up to the time of its birth.

How is the egg fertilized?

Another important issue is how the sperm enters the egg. Outside, the cell is covered with a layer of epithelium, and the sperm must break through the epithelium, for this, it uses the tail. Under these cells is a sticky substance, for which the sperm clings and continues to move on. Several spermatozoa can compete for the first place, however only the fastest of them will reach the nucleus and complete the fertilization process.

How many spermatozoons are waiting for an egg?

The egg is ready for fertilization for a very limited amount of time, about 24 hours. If at this time there are no spermatozoa nearby, fertilization will not occur. However, the spermatozoa themselves are more tenacious, in the genital tract of a woman they can be up to 7 days (on average - 3 days). This increases the likelihood of fertilization.

The egg and sperm are the two main cells from which your baby will later develop, they differ from one another in a variety of characteristics, complement each other and give rise to a new life.