Spermatogenesis refers to the processes of sperm formation. It begins at puberty and continues throughout a man’s life. Here’s everything you need to know about sperm production.
Where does spermatogenesis take place?
Spermatogenesis enables the production of sperm, the male reproductive cells contained in semen. Sperm travel a long way and go through several stages before becoming mobile cells which move in very large numbers.
The production of sperm begins in the seminiferous tubules, long tubes located in the testes measuring between 30 and 70 cm. It is in these tubes that the germ stem cells are located which will then become sperm.
The different stages of spermatogenesis
The process therefore begins in the seminiferous tubules of the testes. In this environment, the temperature is lower (34 ° C) than in the rest of the body, a prerequisite for the production of sperm.
The phases of spermatogenesis
There are three phases in spermatogenesis:
- The multiplication of spermatogonia, also called diploid stem germ cells.
- Meiosis, the stage during which the spermatogonia become spermatids.
- Spermiogenesis which is the differentiation of spermatids into spermatozoa.
The formation of sperm
During these stages, the sperm move and transform. Their path begins in the seminiferous tubules and then continues through the epididymis, a duct wrapped around each testicle in which the spermatozoa acquire their flagellum (allow them to swim quickly). It is in the epididymis that they complete their maturation and are stored. They are expelled during ejaculation: the spermatozoa pass through the vas deferens, mix with the secretions of the seminal vesicles and then of the prostate to form sperm. This whitish liquid then passes into the urethra and is ejaculated through the glans.
How long does spermatogenesis last?
It takes about 70 days for a sperm to develop into a sperm. One milliliter of semen contains between 20 and 200 million sperm. You should know that during ejaculation, a man expels between 2 and 5 ml of semen, or several tens to several hundreds of millions of spermatozoa.
What are the different parts of a sperm?
A sperm consists of a head, an intermediate piece and a flagellum.
The head contains two parts: the nucleus in which the chromosomes are located and the acrosome, the sac containing enzymes necessary for penetration into the oocyte during fertilization.
The middle piece provides the energy that allows the sperm to move. The flagellum is an organ considered as a “motor”, it propels the sperm forward.
What are sperm used for?
Every man’s sperm contains their genetic information. When a sperm enters an egg (a female gamete that carries the woman’s genetic information), it is said that there is fertilization. An egg cell is then formed which will become an embryo and then a fetus with a unique genetic heritage.
Spermatogenesis can be disrupted by different factors
We talk about spermatogenesis disorders when the sperm:
- Lack of vitality;
- Are not numerous enough;
- Have abnormal shapes;
- Cannot be released outside the body or have difficulty being expelled because of an obstruction.
These different problems can hinder the fertilization process and therefore make a man less fertile.
An increase in temperature in the testes may be the cause. A factor that can significantly reduce the number and vitality of sperm and increase the risk of abnormal forms. This rise in temperature in the testes is most often due to varicose veins or the absence of descent of the testes into the bursae.
Hormonal disturbances can sometimes be involved in the event of disturbed spermatogenesis.
Besides the rise in testicular temperature, the reduction in sperm count may be related to exposure to industrial or environmental toxins or to taking anabolic steroids like testosterone and other synthetic male hormones (androgens).
Erectile dysfunction prevents the expulsion of sperm through the glans. It is considered to be a factor in male infertility. Many causes have been identified in erection problems: certain vascular diseases, diabetes, multiple sclerosis, cerebral or nervous disorders (Alzheimer’s disease, Parkinson’s disease, stroke, etc.), drug consumption or even psychological problems.
What is azoospermia?
Finally, azoospermia (complete absence of spermatozoa in the semen) is one of the disorders of spermatogenesis. It can be caused by serious problems with the testicles, damage to other parts of the male reproductive system, cystic fibrosis and retrograde ejaculation (when semen goes into the bladder instead of down into the penis).
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