Why is the skin on men's triangle area dark and wrinkled?

The support and covering of the male scrotum, the suspension of the spermatic cord and the levator testis all play a mechanical protective role on the testicles, which can buffer the vibration of the testicles during walking and exercise, and have a certain significance in preventing trauma. Why is the scrotal skin dark and wrinkled?

The scrotum is like a thin and flexible leather bag, growing between the base of the penis and the perineum. When a person stands, it hangs there, connected to the pubic region, penis skin, inner thigh skin and perineal skin. From the outside, there is a longitudinal scrotal suture on its midline, which is a trace left by the embryonic development.

The scrotal skin is soft and weak, smooth and elastic, with sparse and curly pubic hair. Under the skin is only a layer of tunica fascia, which is mainly composed of smooth muscle, containing dense connective tissue and a lot of elastic fibers. The front and back walls of the tunica fascia have fibers extending to the deep layer in the midline and connecting to each other to form a diaphragm, dividing the scrotum into two small pockets on the left and right, which contain the left and right testicles and epididymis respectively.

There are abundant blood vessels flowing through the tunica carnosus. There are also several layers of fascia and levator testis muscle under the tunica carnosus, which are mainly composed of the aponeurosis of the abdominal wall muscles and the continuation of muscle fibers. There is also a spermatic cord in the scrotum, which is a round cord composed of the vas deferens, testicular artery, venous plexus, many small blood vessels, nerve plexus, lymphatic vessels and capsule.

As for the dark color of the scrotal skin, it is affected by sex hormones. Originally, a person's skin color depends on various pigments, especially the amount of melanin, the thickness of the skin and the contraction or relaxation of blood vessels. The important factor affecting the melanin deposition in the skin is sex hormones. The concentration of sex hormones in the sex organs and other parts is high. As a result of long-term hormone stimulation, a large amount of melanin is deposited and the skin color becomes very dark, especially after wrinkles and thickening.

Based on the same reason, you may have noticed that the nipples and the surrounding areola of adult males are also quite dark! However, the sex hormone levels of little boys are very low, so the skin color does not change much, and the scrotum is similar to the surrounding skin color. This change in pigmentation will only appear after entering puberty.