Structure of the sperm

The sperm cell is called the male gamete (gamete). Its size (without taking into account the length of the tail) is much smaller than the size of the zygote. The microscopic structure of the spermatozoon is due to the need to pass a relatively large distance to reach the egg. It should be noted that this cell has the smallest size in comparison with all human cells.

Structure of the sperm

The gamete contains a head, neck, middle part (body) and tail. The front part of the oval head contains the so-called acrosome. It consists of enzymes, through which the dissolution of the shell of the egg. Behind the acrosome is a nucleus that contains twenty-three male chromosomes. When fertilized, they combine with the twenty-three female chromosomes contained in the egg. In this case, the fertilizing sperm only brings the X or Y chromosome, thus determining the sex of the child.

The gamete cervix performs the connective function between the head and the body. The mobility of the neck allows the head to oscillate during movement of the sperm.

The cell body is made in the form of an axial filament, which consists of mitochondria and microtubules.

The tail continues the middle part (body) and includes microtubules covered with cytoplasm.

The normal structure of the spermatozoon is characteristic for half of all present in the sperm. It should be noted that the presence of defects does not affect the genetic material of gametes. In this case, the defective structure of the sperm can affect its ability to reach the oocyte.

The production of these cells occurs in the convoluted, spermatogenic epithelium tubules of the testicles. These tubules further pass into direct tubules. They, in turn, form an appendage of the testicle. The sperm must pass through all the tubules. Thus, his full maturation occurs. The adnex of the testicle passes into the duct, which passes through the inguinal canal and enters the abdominal cavity. In this case, the duct empties into the seminal vesicles located behind the bladder. Seminal vesicles accumulate spermatozoa and mix them with the secretion of their walls. The secretion includes the necessary nutrients, which contribute to the promotion of sperm to the egg. On the ejaculatory ducts, male sex cells from the seminal vesicles enter the prostate gland. Here they mix with her secret. Chemical compounds and nutrients create an alkaline environment for spermatozoa. The result is a suspension, called sperm. With the onset of male ejaculation, it enters the urethra from the vas deferens, and then is thrown out of the body with force.

Normal is the volume of ejaculate within three to five milliliters, while the number of sperm per one milliliter of sperm should be at least twenty million. In the normal state of the genital organs, a man should not have aggregation of spermatozoa (areas of large congestion). Sometimes such areas can be identified visually - they are distinguished by a large whiteness and density.

At the time of ejaculation, a huge amount of sperm enters the cervix of the female uterus. However, only half of them are able to pass the mucous plug in the uterine neck canal. Of this half of the sperm, in turn, only a small part is able to reach the mouth of the uterus tubes. In this case, the egg is located in one tube of the uterus. As a result, even fewer spermatozoa remain on the way to the ovum, of which not all enter the uterine tube. Thus, the ovule can only reach about two hundred male cells.

How long live sperm

Within a few hours, the gametes remaining in the vagina destroy the acidic environment of vaginal secretions. In the cervix, the sperm can last from three to five days (sometimes longer), depending on the amount of cervical mucus.