Sexual learning - discoveries 'shocking' in history

Studies on sperm, eggs, sex . have created a premise for scientists to better understand the "story" of humans.

Ancient Roman and Greek philosophers used to think a lot about sex. Basically, "sex" in humans or animals is a natural and essential instinct to maintain the race.

In the 4th century BC, Aristotle researcher believed that temperature was an important factor in determining the sex of the fetus. This is true for crocodiles when their incubation temperatures directly affect the later crocodile sex. Aristotle believes that, when doing "that", if the male body temperature is greater than the female, then they will have a son, and if the male body is colder than the female, the girl will give birth.

At that time, there were many strange comments such as the "father of Western Medicine " Hippocrates - when he thought that women with a history of mental illnesses were more prone to uterine dysfunction. Meanwhile, others say, "sex" during lactation will ruin breast milk.

Science and scientific advances have gradually uncovered the secrets of people, the connections between the two opposite sexes. Here are 5 of those secrets.

1. In semen is a "sea sperm"

Dutch scientist Anton van Leeuwenhoek is always curious about what is in the semen after every . thing. In 1677, he answered that question by using a microscope and his own "product" to study.

Although at that time, Leeuwenhoek did not have any knowledge of science, biology or medicine, but with a microscope, he discovered that inside the semen was millions of small individuals. Baby is swimming "kicking".

Although studied since the seventeenth century, it took a lot of time for scientists to explain how sperm play a role in human conception.

At the time of Leeuwenhoek, he said, every human being contained a human being. And this "human " always aspires to " break into" the female eggs so that they can grow, grow and gradually improve themselves.

2. Other eggs are completely human eggs

Scientists believe that female eggs are not easy to track and study like sperm in males. Therefore, until 150 years after sperm was first studied, it was discovered that the unknown number related to eggs.

Earlier, after studying bird eggs, scientists realized that they were not the same as eggs of mammals and humans. Scientist William Cumberland Cruikshank was the first to have the honor of studying mammalian eggs when he analyzed rabbits in 1779.

But it was not until 1872 that Professor Karl Ernst von Baer succeeded in determining the exact development of eggs in mammals and humans.

Although Karl Ernst von Baer's research still stops at the stage . egg testing has not completed a complete conception process, but it has become a premise for scientists to continue later. Further research on human conception.

3. When "two" becomes "one"

At the end of the nineteenth century, scientists debated a lot about the conception of animals in general. There have been two completely opposite views to explain this issue. The first view is that the process of conception is successful because the sperm swim continuously and create vibrations in the uterus, helping the egg to develop into an embryo.

The other view says, when approaching eggs, sperm will create a special chemical compound to stimulate the process of turning eggs into embryos, thereby completing the conception process.

Recognizing the absurdity of both views, in 1872, German researcher Wilhelm August Oscar Hertwig studied sea urchins to find out the process of conception as well as the relationship between sperm and eggs to return. complete embryo. He was noted during this study when it was discovered that only one sperm could enter the egg, the process of conception would be successful.

4. "War" of 150 million sperms to get 1 egg

The journey after the sperm comes out of the male body and comes to the uterus like a high-speed race. Since the "explosive gun", more than 150 million tiny athletes will try their best to reach their destination.

But unlike the real-life race, the sperm battle was much more intense, only 15% of the sperm passed through the cervix to reach the egg. By then there were only about 1,000 "riders" continuing the game.

After all, only a few of the strongest heroes can reach their destination. If you are lucky, some of these winners will be won, the rest will be eliminated.

In the early twentieth century, when the concept of hormones was still unclear, female ovulation is still a mystery without an answer. In some animals, if not conceived successfully at one ovulation, the lining of the uterus will rupture to "replace the blood" and continue for a new cycle . luckier.

Based on these factors, Edgar Allen's team with Edward A. Doisy re-simulated the entire process in order to find the role of hormones in each cycle. The experiment performed on female mice showed that hormones are one of the important factors leading to ovulation. If there is no or insufficient amount of hormones, this cycle will not occur.

5. People are difficult to "one wife, one husband"

With the development of mankind, the problem of "one wife and one husband" is no longer strange. This helps each person choose more carefully to find his perfect half, not limited to the physical situation as in the ancient times.

The concept of love is increasingly consolidated and affirmed more clearly in each individual, now that sex no longer becomes an essential need without love. This problem has led scientists to suffer, they cannot explain the connection between the two concepts until the early 90s of the last century.

Researcher C. Sue Carter has done a lot of research on hamsters because they also follow the same "one-husband-one-husband" regime as humans. She discovered that rats produce oxytocin in the brain when having sex, which makes animals more closely related than other species.

In 1998, following Carter's study, scientist Thomas R. Insel discovered that in the brains of copper rats, oxytocin and dopamine were closely linked. These two factors have led to a sense of comfort, as well as a connection between the mouse and the mouse. For that reason, once they have chosen the other half, they will be together for the rest of their lives.

Like the hamster's brain, the human brain also possesses oxytocin and dopamine, but the bonds of the two compounds are slightly worse than those of the hamsters. So people also follow the one-husband-one-husband regime, but not always . as faithful as rats.