What is the normal penis size at 12 years old?

Male genitals, also known as penis, is a basic professional term in biomedical engineering, referring to the external male reproductive organs of higher education vertebrates. For men, the male genitals are undoubtedly the most important and symbolic organs of the human body, but different men's penises have some different shapes and characteristics, so what is the standard shape of a normal penis?

shape

The penis of different animals has different shapes, especially the glans part of the penis. The penis of a horse is relatively thick and cylindrical with slightly flattened sides; the penis of cattle and sheep is relatively thin, forming an "S" shape behind the scrotum; the penis of a pig is also thin, forming an "S" shape in front of the scrotum.

Many marsupials, except two large Australian kangaroos, have a bifurcated penis (that is, two columns at the end of the penis).

The male genitals can be divided into three parts: the front end of the penis glans, the middle part of the male genital body and the back part of the male genital root.

Penis glans

The glans penis is a large part of the front end of the male genitals, also known as the "glans penis". Its appearance varies depending on the breed. The glans penis of cattle is more pointed and slightly twisted. The glans penis of horses is blunt and round, with the cervical vein producing the glans corona, and a urethral orifice (2.5 cm) in the glans penis fossa. The glans penis of pigs is spiral-shaped and has a shallow spiral groove. The glans penis of sheep is a cap-shaped bulge, with a urethral orifice extending into the front of the glans penis (the glans penis of lambs is curved and long, and the glans penis of sheeps is thick and straight). The glans penis of dogs has a penis bone (large dogs reach 10 cm), and there are two glans balls at the back of the glans penis. The glans of the penis of tigers and cats has keratinized nipples.

Male genital root

The posterior end of the male genitalia develops into the male genitalia root, which is hidden deep in the skin of the scrotum and vulva, and is fixed to the inferior phalangeal branch and the sciatic nerve branch, and is a fixed part.

The male root is the starting point of the male genitals.

Male genital crus - It starts from the penis and divides into two male genital crus, which are fixed on both sides of the pubic arch.

What is the normal penis size at 12 years old?

At the age of 12, some boys have not yet started to grow and develop, and there is no standard for the length of the male genitals. The length of an adult's genitals after erection is 11-16cm, and the diameter is 10.8cm. Under normal circumstances, it is 7-9cm long and the diameter is 6.9-9.4cm. With the growth of age, the perfection of male testicles, under the action of male hormones, male secondary sexual characteristics gradually become more obvious, and gradually appear after 12-13 years old, sweat hair, beard, armpit hair, voice change and Adam's apple growth, male testicles and penis enlargement, metabolizing sperm night and causing frequent spermatorrhea, epiphyseal lines healed, stout stature, broad shoulders, rough skin, etc.