The primary characteristics of the human body refer to

Testicles and ovaries produce sperm and eggs, which are unique to men and women respectively, and secrete sex hormones. Sperm and eggs are "messengers" of human reproduction and play a decisive role in the process of sexual reproduction. Therefore, testicles and ovaries are called main sexual organs, while other reproductive organs other than testicles and ovaries are called accessory sexual organs. Accessory organs play an auxiliary role in the reproductive process. In medicine, gender differences caused by different reproductive organs of men and women are called primary sexual characteristics, such as testis and penis of men, vagina and uterus of women. Because of the different hormones secreted by male and female glands, after puberty, men and women began to have a series of gender-related characteristics, called "accessory sexual characteristics", also known as secondary sexual characteristics. For example, a bearded man is burly, muscular, with a prominent Adam's apple and a deep voice; Women, on the other hand, have plump fat, delicate skin, high-pitched tone, developed breasts and broad pelvis. Compared with women, the bones and muscles in the shoulders and chest are developed, and the shoulders are wider than the hips; In women, the pelvis is wider and the fat layer at the waist is thicker. Therefore, hip breadth's shoulders constitute different physical characteristics of men and women, which are all subsidiary characteristics.

Quasi-sexuality is determined by sex hormones secreted by gonads. If the gonadal function is damaged, the accessory sexual characteristics will change and produce some abnormal manifestations.

In addition, the familiar "androgyny" is also an example of abnormal accessory sexual characteristics, which can be divided into "true androgyny" and "false androgyny". True hermaphroditism refers to both male and female gonads in the body, that is, both testis and ovary; In pseudohermaphroditism, the gonad is unisexual, that is, there are only male testicles or female ovaries, but the external genitalia and accessory sexual characteristics are more contradictory to the gonad in different degrees and more common than true hermaphroditism. Such as female pseudohermaphroditism, the gonad in the body is ovary, which has female secondary sexual characteristics (accessory sexual characteristics), but the external genitalia is like male. Male pseudohermaphrodites, on the other hand, have male gonads, testicles and accessory sexual characteristics, but their external genitals are like women. After surgery and hormone therapy, hermaphroditism can be corrected. People who suspect hermaphroditism should see a doctor as soon as possible, make a clear diagnosis and treat them in time, otherwise, jokes like "true men and false women get married" and "true women and false men get married" will often be made.