the human reproductive system integrates internal organs and external genitalia. They work together to help people complete their sexual life and breed new life together. Recently, the US “life science” network summed up 10 unknown and interesting facts about the reproductive system.
1. Men with high voice have more sperm
in a study involving many European countries, scientists found that although women think men with low voice are more masculine and attractive, their sperm concentration is lower than their peers with high voice.
2. Testicular function affects appearance
testis is not only very important for the realization of reproductive function, but also plays a key role in the normal development of boys’ puberty. Testosterone produced by the testis is responsible for the development of secondary sexual characteristics, including sound, facial features and body hair growth. In other words, testicular function can affect people’s appearance to a certain extent.
3. Some women are born with two wombs
. During the normal development of the fetus, the formation of the uterus begins with two small tubes, and then they are connected into a hollow organ – the uterus. Sometimes the two pipes are not completely connected, forming two independent structures. The disease is called double uterus, and its incidence rate is 1/2000 in women worldwide.
4. The reproductive system of some animals is very strange
although the internal system of animals is very similar to that of humans, there are obvious differences in the reproductive system. For example, female kangaroos have three vaginas, two transverse vaginas are used to receive sperm during mating, and the middle vagina is used for childbirth. Accordingly, male kangaroos have two toothed penises for insemination to the transverse vagina. Most birds have no penis or vagina. They only have cloaca. It is a separate hole for excretion and reproduction.
5. Infertility is more common than expected
in the medical community, if a couple fails to conceive after a year of unprotected sex, it is called infertility《 According to a report published in the Journal of fertility and infertility in 2013, nearly one sixth of adult couples in the United States are infertile.
6. Ancient Egyptians used contraception thousands of years ago.
you may think contraception technology is a new invention, but birth control began nearly 4000 years ago. The earliest written records of contraceptive technology came from ancient Egypt. One of the contraceptive methods was to let a woman lie on a bed with sodium carbonate and put honey in her vagina.
7. Men have more germ cells than women
there is a significant difference in the number of germ cells generated by men and women. At birth, women have 1-2 million eggs, and only about 300000 remain when puberty comes, of which only 300-400 ovulate before menopause. Each man will produce more than 500 billion sperm cells in his life, and a healthy man will release 1.2 million sperm cells in one ejaculation.
8. The vagina is very acidic
what the vagina and tomato have in common is that they are very acidic. The pH value of tomato is between 4.0 and 4.7 (7 is neutral), and the average pH value of vagina is 4.5. A large number of microorganisms in the vagina can only thrive in an acidic environment. Without these beneficial bacteria guarding the vagina, other pathogenic bacteria will enter and destroy the vaginal ecosystem.
9. The average length of the penis is 14 cm
a survey report published in the Journal of sexual medicine shows that the average length of the penis after erection in American men is 14.2 cm. According to the report, the shortest penis after erection is 4cm and the longest is 26cm.
10. The reproductive system contains the largest and smallest human cells
human cells have different shapes and sizes and perform many different functions. However, the largest and smallest cells in the human body are germ cells. The sperm cells produced by men are the smallest, only 5 × 3 microns, the egg produced by women is the largest cell in the human body, with a diameter of about 120 microns.