What's the difference between boys and girls?

First, the reproductive system is different.

1, Female reproductive system: Female reproductive system includes internal and external reproductive organs and related organizations. Female internal genitalia include vagina, uterus, fallopian tube and ovary. Female genitalia refers to the exposed reproductive organs, also known as vulva. Include pudendum, labia majora, labia minora, clitoris and vaginal vestibule.

2. Male reproductive system: The male reproductive system consists of internal genitalia and external genitalia. Endogenous genitalia consists of gonad (testis), vas deferens (epididymis, vas deferens, ejaculatory duct and urethra) and accessory glands (seminal vesicle, prostate and urethral gland). The external genitalia includes scrotum and penis.

Second, the average height in China is different.

1. Average height of girls in China: average height of women155.8cm.

2. Average height of boys in China: average height of men 167. 1cm.

Extended data:

The first menstruation of a girl is medically called "menarche". Menstruation is the most obvious sign that girls enter puberty. It marks the first stage of female sexual and physiological development. Normal women's menstruation generally lasts for 28-30 days and lasts for about 3-7 days.

A considerable number of girls have irregular menarche for a period of time, sometimes their menstruation is advanced or postponed, or it only recovers every few months. The main reason is that the ovary is immature and unstable, and it is not necessary to ovulate on time every month. As the girl grows older, the menstrual cycle naturally becomes more normal.

Baidu Encyclopedia-Girls

Baidu Encyclopedia-Female Reproductive System

Baidu Encyclopedia-Male Reproductive System

Baidu Encyclopedia-Average Height of Men in China