Why do men have beards and most women don't?

Careful you may find that adults are like this, and students around you are rarely like this. It turns out that from the upper grades of primary school to junior high school and even high school, the bodies of boys and girls will change little by little, and this period is called adolescence.

During this period, the bodies of boys and girls will undergo different changes. For men, one of the biggest changes is to grow a beard. After entering adolescence, boys become strong and have long beards. This is because at this stage, in order to maintain the physiological gender function, boys will secrete a lot of androgen. The fine hair on the face becomes a hard beard, which is the role of androgen. Androgen in girls is extremely low, so girls don't grow thick and hard beards.

Beard, commonly known as beard, refers to the hair that grows on men's upper lip, chin, cheeks, cheeks or neck. If we want to distinguish carefully, "Hu" originally refers to the hair that grows on the mouth, while the upper lip is called "moustache" (in Cantonese, moustache, moustache and two-lipped beard), the chin is called "goatee" and the temple is connected with the chin. Men after puberty generally have beards. Beard grows faster than hair, which is the result of androgen. The more vigorous the reproductive function, the faster the beard grows. Beard has more blood vessels than hair roots, and nutrients are easy to obtain. Therefore, the beard that has just been shaved will grow back in a few days.

A long beard is a sign of a man's secondary sexual characteristics. The emergence of secondary sexual characteristics is stimulated by androgen secreted in the testis after men enter puberty. Before 1 1 years old, there were few androgens in boys, and there was not much difference in signs between men and women. There is no strict time limit for the puberty development of boys, which is generally from 10 to 14 years old.