Why do testicles move?

Some people do not understand why the testicles move on their own, but in fact there are many meridians on the testicles, and these meridians will naturally produce a feeling of movement during the beating process. This is not due to any pathological reasons, but common physiological reasons. However, since many people do not know much about their own body organs, many adverse phenomena will occur and will not be dealt with in time.

The testis is composed of the seminiferous tubules and interstitial cells. The epithelium of the seminiferous tubules is composed of spermatogenic cells and supporting cells. The original spermatogenic cells are spermatogonia, which are attached to the basement membrane of the seminiferous tubules. Starting from puberty, spermatogonia develop in stages to form sperm. The process of sperm production is: spermatogonia → primary spermatocytes → secondary spermatocytes → spermatids → sperm. In the wall of the seminiferous tubule, spermatogenic cells at different stages of development are arranged sequentially, from the basement membrane to the tubular lumen, including spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, and differentiating spermatozoa, until mature spermatozoa separate from the supporting cells and enter the tubular lumen. It takes about two and a half months for spermatogonia to develop into sperm.

Support cells provide nutrition for reproductive cells at all levels and play a role in maintenance and support. They provide a suitable microenvironment for the differentiation and development of spermatogenic cells, and the blood-testis barrier formed by support cells prevents the antigenic substances of spermatogenic cells from entering the blood circulation and causing immune response.

Sperm production requires an appropriate temperature. The temperature in the scrotum is about 2°C lower than that in the abdominal cavity, which is suitable for sperm production. During embryonic development, if the testicles do not descend into the scrotum for some reason but remain in the abdominal cavity or inguinal groove, it is called cryptorchidism. Then the seminiferous tubules cannot develop normally and no sperm is produced. If the testicles of mature animals are heated or experimental cryptorchidism is performed, the degeneration and atrophy of spermatogenic cells can be observed.

Newly formed spermatozoa are released into the lumen of the vas deferens. They do not have the ability to move by themselves, but are transported to the epididymis by the contraction of the peripheral muscle-like cells of the tubules and the movement of the lumen fluid. In the epididymis, the spermatozoa further mature and acquire the ability to move. A small amount of spermatozoa can be stored in the epididymis, while a large amount of spermatozoa are stored in the vas deferens and its abdomen. During sexual activity, spermatozoa are transported to the urethra through the peristalsis of the vas deferens. Spermatozoa mix with the secretions of the epididymis, seminal vesicles, prostate glands and bulbourethral glands to form semen, which is ejaculated out of the body during orgasm. A normal man ejaculates about 3-6 ml of semen each time, and each ml of semen contains about 20 million to 400 million spermatozoa. Less than 20 million spermatozoa make it difficult to fertilize the egg.