- How spermatogenesis happens
- 1. Germinative phase
- 2. Growth phase
- 3. Maturation stage
- 4. Differentiation phase
- Regulation of spermatogenesis
Spermatogenesis corresponds to the process of formation of sperm, which are the male structures responsible for egg fertilization. The formation of sperm usually begins at 13 years of age, being continuous throughout life and decreasing in old age.
Spermatogenesis is a process highly regulated by hormones, such as testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH). This process happens daily, producing thousands of sperm per day, which are stored in the epididymis after production.
The sperm can remain stored without losing the capacity of fertilization, since they are in an inactive state controlled by some inhibitory substances present in the secretion of the ducts. After ejaculation, sperm become mobile and able to fertilize the egg.
How spermatogenesis happens
Spermatogenesis takes place inside seminiferous tubules, which are structures present in the testicles responsible for the differentiation of germ cells into sperm which, among other cells, are made up of Sertoli cells, which are important for the nutrition and maturation of germ cells, favoring the process spermatogenesis.
Spermatogenesis is a complex process that lasts between 60 and 80 days and can be didactically divided into a few steps:
1. Germinative phase
The germinative phase is the first phase of spermatogenesis and happens when the germ cells of the embryonic period go to the testicles, where they remain inactive and immature, and are called spermatogonia. When the boy reaches puberty, sperm, under the influence of hormones and Sertoli cells, proliferate more intensely through mitosis-type cell divisions and give rise to primary spermatocytes.
Before puberty there is formation of spermatogonia, but in lesser intensity, because the endocrine and reproductive systems are still developing.
2. Growth phase
The formed primary spermatocytes increase in size and undergo a meiosis process, so that their genetic material is duplicated, becoming known as secondary spermatocyte.
3. Maturation stage
After formation of the secondary spermatocyte, the maturation process takes place to give rise to the spermatoid through the meiotic division.
4. Differentiation phase
Corresponds to the period of transformation of the sperm into sperm, which lasts approximately 21 days. During the differentiation phase, which can also be called spermiogenesis, the formation of the acrosome by the Golgi complex occurs, which is a structure present in the head of the sperm that contains several enzymes that favor the penetration into the oocyte and its fertilization, formation of the flagellum, allowing sperm mobility, elimination of residual cytoplasm and compacting of nuclear material.
Despite having a flagellum, the sperm formed only actually have motility when they cross the epididymis, which is a highly contorted duct present in the testis responsible for the collection and storage of sperm produced in the testis, acquiring motility and fertilization capacity between 18 and 24 hours.
Regulation of spermatogenesis
Spermatogenesis is regulated by several hormones that not only favor the development of male sexual organs, but also the production of sperm. One of the main hormones responsible for the production of sperm is testosterone, which is a hormone produced by Leydig cells, which are cells present in the testis.
In addition to testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) are important for the production of sperm, as they stimulate Leydig cells to produce testosterone and Sertoli cells, so that there is the transformation of spermatoids. in sperm.
Understand how hormonal regulation of the male reproductive system works.
