We already know that the mother-to-be provides the egg, the father-to-be provides the sperm, and the little life is the result of the intimate contact between the sperm and the egg. Sperm can survive in a woman’s fallopian tubes for 2-3 days, and the egg can survive for about 1 day, so if you share a room around the time a woman ovulates, the sperm and the egg may meet in the juxtaposition of the fallopian tubes. On each date, there is usually only one egg, but there are hundreds of millions of sperm, and ultimately there can only be a sperm and egg combination, the formation of fertilized eggs, to complete the process of fertilization. So, the “bride” how to choose their own “man of their choice” in a large number of applicants? First, the starting line of the Warriors Normal sexual intercourse, hundreds of millions of sperm are discharged into the female vagina, they are eager to try, ambitious to run to the egg side. But the journey is a long one – from the cervix to the fallopian tube is about 15 centimeters, which is thousands of times the length of the sperm itself – and it’s fraught with danger. First of all, the vagina is generally an acidic environment, and sperm are better adapted to an alkaline environment, so, in the vagina for 2 hours, 90% of the sperm will die, and generally survive no more than 8 hours. This place can not stay, the sperm scramble to the end of the “marathon” race – the fallopian tube potbelly forward, because there will be a wonderful and tragic story waiting for them. The long and arduous march of the sperms in the acidic environment of the vagina anxiously searching for the entrance to the cervix, at which point the sperms in the outer layer of the semen in contact with the vaginal wall die a martyr’s death. The rest of the egg-seeking army, in the vicinity of the cervix, inevitably collide with each other, and the casualty figures are inevitably high. After coming to the mouth of the cervix, how to pass through the cervical canal into the uterine cavity is another problem, is what we said earlier that the cervical mucus blocked the way. But if this is the time when the woman is ovulating, the problem is better. The amount of cervical mucus and thin, easy to sperm through; contains a reduced number of white blood cells, thereby reducing the opportunity to eat sperm; cervical mucus at this time the alkaline has also been enhanced, and sperm is alkaline anaerobic, so it plays a role in protecting the sperm. In other periods, the cervical mucus is small and sticky, it is difficult for sperm to pass through; it also contains a large number of leukocytes, which will eat sperm from time to time. In addition, there are countless protein fibers in the cervical mucus, which seem to form a fence, only the strong sperm can cross the obstacles, while those deformed sperm or weak sperm can not pass. Therefore, the sperm that are screened by the cervical mucus to enter the uterine cavity and fallopian tubes are also the best. Sperm through the cervical tube will also have to go through a long journey in the uterine cavity, and “small athletes” with little physical strength will also be abandoned halfway. Only the strong-willed and enduring can reach the opening of the fallopian tube in the uterine cavity. Only one of the two fallopian tubes has an egg. This elite unit now has to be split in two, and the sperm that flounders swims out of the umbrella end of the fallopian tube and is sacrificed in the abdominal cavity. The sperm that went the right way also had to pass through the narrow isthmus of the fallopian tube, and after another loss of life, only about 20-200 sperm were able to triumphantly reach the jugular abdomen. Champion to reach the end of the time only a few minutes, most sperm achievements for 1-1.5 hours. Third, the wonderful process of fertilization The process of combining sperm and egg is called fertilization, and the whole process takes about 24 hours. When the egg enters the fallopian tube, it is wrapped in a layer of hyaline band, and then outside is a circle of radial crowns, which play the role of protecting the egg, and at the same time can increase the target, but also release a kind of seductive spermatozoa in order to facilitate the sperm’s search and adhesion. The sperm that find the egg swarm up to it, releasing acrosomal enzymes from their acrosomes that dissolve the radial crown and zona pellucida on the periphery of the egg. They bore their heads into the outer wall of the egg like a constantly rotating drill, with their tails constantly slapping in an effort to get through the radial crown. The strongest sperm is the first to cross the zona pellucida and enter the egg, which immediately closes the door to any “third party”. Next, the embracing sperm and egg undergo a series of changes until the nucleus of the spermatogonium and the nucleus of the oogonium merge with each other to form a fertilized egg, announcing the completion of fertilization and marking the birth of new life. It also marks the birth of a new life. It is not easy for the sperm and the egg to unite. How many difficulties and obstacles did this devoted man go through to achieve the final victory in the fierce competition and win the heart of his beloved, so that love can withstand the test. Meanwhile, this strongest and best sperm will surely lay a solid foundation for a healthy and smart baby in the future.