Why are genitals black?

The reproductive organs are pink at the beginning, but because of the frequent condensation of melanin, they will turn black. The main function of the reproductive organs is to help us predict the menstrual cycle, and they also represent a person's secondary sexual characteristics. In addition to these, the reproductive organs are covered with pubic hair after puberty, so pubic hair will cause the reproductive organs to turn black.

Physiological effects

Absorbs sweat and mucus

Pubic hair is not useless, but grows to protect our bodies. Pubic hair can absorb the sweat and mucus secreted from these parts and dissipate them around, which is beneficial to physical health. During sexual intercourse, it can also increase the pleasure caused by friction on the external genitalia. In addition, pubic hair also has the function of keeping warm, protecting the normal survival temperature of sperm and eggs.

Reduce friction and pain

In addition to being a sexual characteristic, pubic hair can also reduce friction and pain caused by rapid movements during sexual intercourse. In addition, the sweat gland ducts in the human pubic area are relatively large and abundant, and the amount of sweat is high. In addition, the hidden area is prone to poor ventilation. The presence of pubic hair can play a role in "ventilation".

Menstrual cycle

General Introduction

Pubic hair is one of the secondary sexual characteristics of the human body. Pubic hair begins to appear in girls between the ages of 11 and 12, and in boys between the ages of 12 and 15. If pubic hair does not grow or is sparse at this time, it is medically called alopecia. Women with alopecia are commonly known as "white tigers", and a man with chest hair, navel hair and pubic hair connected into a single line is called a "blue dragon". In the old society, there were sayings that "blue dragons and white tigers are unlucky" and "a man with alopecia will kill his wife, and a woman with alopecia will kill her husband", which are pure nonsense. This puts a lot of mental pressure on patients, and some even dare not to fall in love.

puberty

Generally speaking, after the onset of puberty, pubic hair grows from the pubic follicles of adolescents due to the effects of estrogen and testosterone. The androgens in men are secreted by the testicles, and there is also a certain amount of estrogen in women, which is secreted by the adrenal cortex and ovarian interstitium.

Whether male or female, the presence and density of pubic hair is related to the level of estrogen and androgen in the body, as well as the sensitivity of the pubic hair follicles to estrogen and androgen. For those who simply do not grow pubic hair but are normal in other aspects, it may be that the pubic hair follicles are insensitive to their own estrogen and androgen. This is not pathological and has nothing to do with anything. It neither affects your physical health nor your marriage or fertility. Therefore, there is no need to worry about it, and don't believe in those nonsense.

Disease issues

Of course, in a very small number of people, it may be caused by disease, such as hypothyroidism, and the pubic hair may be sparse. For example, inflammation, tumors or trauma may cause structural damage and functional impairment of the hypothalamus-pituitary-adrenal axis, thus affecting the secretion of sex hormones. Or it may be due to congenital diseases or some unexplained diseases, such as idiopathic Addison's disease, which affect the secretion of sex hormones, manifesting as menstrual disorders, amenorrhea, sparse pubic hair, sexual dysfunction, etc.

For example, the influence of drugs. Long-term and large-scale use of glucocorticoids before puberty will feedback inhibit the function of the hypothalamus-pituitary-adrenal axis, causing renal cortex dysfunction or even atrophy, and reduced or no secretion of estrogen and androgen, resulting in sparse or no pubic hair.

Most people have sparse or no pubic hair, and they have poor local sensitivity. If it is caused by a disease, pubic hair will grow again once the disease is cured, and it will not affect the marriage and sexual life after marriage.