Also known as the genitals, it is the organ that the organism produces germ cells to breed. The genitals of humans and higher animals include male seminal vesicles, vas deference, testes, penis, etc.; the male reproductive system consists of two parts, the internal and external genitalia. The external genitalia include the scrotum and the penis; the internal genitalia include the gonads (testicles), the drainage channels (epididytestosus, vas deferens, ejaculatory ducts, and urethra) and the accessory glands (the seminal vesicles, prostate, and urethral glands); female ovaries, fallopian tubes, Uterus, vagina, etc. Sexual organs of humans and higher animals are essential for sexual activity.
Male baby sex organ
Prepubertal boys have a small increase in testicular volume. The testicular volume is generally 1 to 2 ml, rarely 3 ml, and the development is also incomplete. The seminiferous tubules are narrow and strip-like, with no obvious lumen. After entering puberty, the testes develop rapidly and the testicular volume increases with age. Testicular enlargement is usually the first sign that a boy enters puberty. According to the survey results of students in the suburbs of Harbin, the testicles began to develop rapidly from the age of 10, when the testicular volume averaged 2.89 ml, and the testicular volume increased significantly with age. By the age of 15, the volume averaged 13.5 ml, 5 years. It has increased by 10.6ml with an average annual growth of 2.1ml. The peak age of testicular growth is 13 years old, when the testicular volume has reached 10ml. After 2 to 3 years, the growth rate slowed down slowly, and the average age of 18 to 20 years at the end of puberty was 18.0 ml. At the same time as the testicles are enlarged, the length and curvature of the seminiferous tubules also increase rapidly, and the spermatogonia divides and multiplies into various stages of spermatogonia. At the same time, the epididymis, seminal vesicles, and prostate are rapidly developed along with testicular development, and the lumen of the vas deferens gradually thickens and grows. After the sexual organs develop to a certain extent, the testicles begin to produce sperm . At the same time, the prostate and seminal vesicles are gradually matured with testicular development and produce secretions. Sperm is mixed with these secretions to form a milky white liquid, which is semen.
Boy sex organ
After the boy enters puberty, the penis and scrotum begin to develop rapidly. The development of the penis and scrotum can be divided into five stages.
In the first stage, the baby’s state, from the beginning of birth until the beginning of puberty, the external genitalia increased slightly, but the appearance of the overall appearance showed little change.
In the second stage, the scrotum begins to increase, and the skin of the scrotum becomes red and the texture changes.
In the third stage, the length of the penis increases, the width also increases slightly, and the scrotum grows further.
In the fourth stage, the length and width of the penis are further increased, and the penis head is formed. The scrotum is further enlarged and the skin color of the scrotum becomes darker.
In stage 5, the external genitalia is as large as an adult.
There are large differences in the development of penis and scrotum. Some boys develop penis and scrotum at the age of 15 to reach adult size, while some boys are fully developed until 18 years old (occasionally even older).
In the first stage, the baby’s state, from the beginning of birth until the beginning of puberty, the external genitalia increased slightly, but the appearance of the overall appearance showed little change.
In the second stage, the scrotum begins to increase, and the skin of the scrotum becomes red and the texture changes.
In the third stage, the length of the penis increases, the width also increases slightly, and the scrotum grows further.
In the fourth stage, the length and width of the penis are further increased, and the penis head is formed. The scrotum is further enlarged and the skin color of the scrotum becomes darker.
In stage 5, the external genitalia is as large as an adult.
There are large differences in the development of penis and scrotum. Some boys develop penis and scrotum at the age of 15 to reach adult size, while some boys are fully developed until 18 years old (occasionally even older).
Girl sexual organ development
After the girl enters puberty, the internal and external genitalia begin to develop rapidly under the action of sex hormones. For example, the weight of the ovary is only 1.91 grams at 6 to 10 years old. After the onset of puberty, the ovary weight can reach 4.04 grams from 11 to 15 years old and 8.34 grams from 16 to 20 years old. When the menarche comes, the ovaries are not yet fully mature, and the weight is generally only 30% of adults. With the maturity of the ovary, the function is gradually improved. On the one hand, mature ovaries have periodic ovulation function, on the other hand, they can continuously secrete estrogen, progesterone and a small amount of androgen, so that other reproductive organs can develop rapidly.
After puberty, the diameter of the fallopian tube increases, and the mucosal epithelium of the lumen appears wrinkled and gradually succulent.
The uterus develops rapidly from the age of 10, and its volume and weight increase significantly. The shape of the uterus, the ratio of the length of the uterus to the length of the cervix is roughly equal from the age of 10, and gradually develops to the morphology of the adult uterus, that is, the uterus is relatively large, the cervix is relatively small, and the ratio of the adult uterus to the cervix is 2: 1. Endometrial thickness did not change significantly before menarche. Near the menarche, the endometrium is thickened by the action of estrogen, and functional periodic changes occur.
In the early years, the vagina is a small lumen, the mucous membrane is thin and dry, and there is a small amount of secretion, which is neutral or alkaline. After the onset of puberty, the vagina becomes longer and wider, the mucosa thickens and wrinkles, the color is gray, and the secretions increase. Vaginal secretions change from alkaline to acidic.
The external genitalia also gradually changed from juvenile to adult, the labia minora became enlarged, the labia majora became hypertrophy, pubic hair appeared, and pigmentation was observed.
After puberty, the diameter of the fallopian tube increases, and the mucosal epithelium of the lumen appears wrinkled and gradually succulent.
The uterus develops rapidly from the age of 10, and its volume and weight increase significantly. The shape of the uterus, the ratio of the length of the uterus to the length of the cervix is roughly equal from the age of 10, and gradually develops to the morphology of the adult uterus, that is, the uterus is relatively large, the cervix is relatively small, and the ratio of the adult uterus to the cervix is 2: 1. Endometrial thickness did not change significantly before menarche. Near the menarche, the endometrium is thickened by the action of estrogen, and functional periodic changes occur.
In the early years, the vagina is a small lumen, the mucous membrane is thin and dry, and there is a small amount of secretion, which is neutral or alkaline. After the onset of puberty, the vagina becomes longer and wider, the mucosa thickens and wrinkles, the color is gray, and the secretions increase. Vaginal secretions change from alkaline to acidic.
The external genitalia also gradually changed from juvenile to adult, the labia minora became enlarged, the labia majora became hypertrophy, pubic hair appeared, and pigmentation was observed.
What is the normal length of a male sex organ?
The adult penis is 11-16cm long and 10.8cm in circumference after erection; it is 7-9cm in length and 6.9-9.4cm in circumference in nature. If the condition is less than 5 cm in the weak state and less than 10 cm in the erection, the penis can be called short. As most men, the sexual maturity is 18 years old, and the basic development is almost the same.
