Contents
How are sperm produced?
The delicate operation begins in the seminiferous tubes of the testes, where the temperature is lowest (34 ° C). A sine qua non for their proper functioning because if the testicles were located inside the body itself, the body temperature (37 ° C) is too high for the formation of spermatogonia, the cells that will turn into sperm. In addition, the latter migrate during their transformation and acquire new components at each stage. Thus, from the seminiferous tubes of the testes, they pass into the epididymis, a small duct overhanging the testis in which they gain their flagella, allowing them to move. Finally, the last stop: the seminal vesicles where they mix with the liquid that will be propelled at the time of ejaculation. To note : man can remain fertile with only one testicle, if it works normally.
Semen contains millions of sperm
Ce opaque and whitish liquid is secreted in the seminal vesicles where it is enriched in nutrients (amino acids, citric acids, fructose…) but also in the prostate which produces approximately half of the sperm. There, this fluid mixes with the sperm arriving through the vas deferens (a gateway between the epididymis and the vesicle) to form sperm, that is, the fertilizing semen. With each ejaculation, the man sheds 2 to 6 ml of semen, containing about 400 million spermatozoa.
Are there times that are more fertile than others for humans?
Spermatogenesis begins at puberty and continues throughout life, every day, 24 hours a day. As in women, there are no cycles. Unless there is a medical problem causing infertility, a man is therefore never short of sperm. However, after 50, things change a bit : sperm are less numerous and of lower quality. But this has nothing to do with female fertility, which ends permanently at menopause.
Spermatogenesis is what designates the sperm production process. Spermatogenesis lasts a little over 70 days (about two and a half months). It takes place in several stages. At first, it starts with germline stem cells, which are called spermatogonia. These multiply and turn into spermatocytes, then spermatids and finally spermatozoa. A spermatogonia alone gives between 30 and 50 sperm. It is during this last stage that a cell division takes place (meiosis), during which the cell loses half of its chromosomes. The sperm is thus provided with 23 chromosomes. When they meet the oocyte, which also has 23 chromosomes, they form an egg with 46 chromosomes.
Can we optimize male fertility?
In men, no need to target the good days as in women. On the other hand, tobacco (like alcohol) significantly reduces fertility in men, in particular by altering the quality of sperm. Stopping smoking allows you to regain optimal fertility as soon as you stop smoking since sperm keep renewing themselves. A diet high in saturated fat decreases fertility! So avoid industrial dishes, pastries, rich dishes (cheeses, cold cuts, meats in sauces) and choose good fats (like omega 3). Regular physical activity contributes to good sperm health and allows you to fill up with vitamin D. In general, it is advisable to observe a healthy lifestyle with regular bedtime, limited time in front of screens and avoiding exposure to endocrine disruptors.
Yellow, transparent sperm: what does the color mean?
Usually semen is whitish in color, but it can also be transparent or slightly pale yellow. When the semen is yellow, this may be a sign of an infection which can affect fertility. It can also indicate the oxidation of spermine, a protein of which it is made especially when intercourse is not regular. In case of pronounced semen color, it is recommended to perform a bacteriological examination of semen prescribed by a healthcare professional.
Are sperm fragile?
Sperm are sensitive to acidity which neutralizes them. However, the female vagina is a more or less acidic environment (it becomes more acidic after ovulation). But during its production cycle, the sperm gets a shield: seminal fluid (which constitutes the sperm) adorned with anti-acidity virtues. This fluid protects the sperm. Heat also makes sperm more vulnerable through wearing tight clothing, taking baths too often, being inactive in a vehicle or in an overheated workspace.
How does the sperm fertilize the oocyte?
He has several tools to his credit. It is in fact composed of several parts which all intervene in the fertilization. First, the head which itself comprises two distinct parts: the acrosome, filled with an enzyme that can perforate the shell of the oocyte, and the nucleus, carrying the chromosomal baggage of the cell (which will blend into the oocyte to become an egg). The intermediate piece located at the base of the head is a reserve of nutrients to allow the survival of the sperm while awaiting fertilization. Finally, the flagellum allows him to move to get as quickly as possible to the ovum.