Pathogenesis of male infertility

Pathogenesis of male infertility

Destroying semen can damage new sperm cells, preventing them from leaving their testicular appendage. It is recommended that men ejaculate every two or three days to keep the sperm quality in optimal condition.

During ejaculation, about 250 million sperm start moving through the ejaculatory duct and the urinary tract (urethra) outwards. The movement of spermatozoa is provided by the contraction of the muscles of the ejaculatory duct and the urethra, which are accompanied by pleasant organic sensations. As a rule, the sperm is released in several portions. Most sperm cells are contained in the first portion, the second and third contains mainly the secret of additional male glands – prostate and seminal vesicles.

Pathogenesis of male infertility

The secret of the additional glands (prostate and seminal vesicles) is necessary to ensure the vital functions of sperm after ejaculation. In case of inflammatory or other pathological process in the prostate or seminal vesicles, the composition of their secret can change, which disrupts the functioning of sperm and reduces the likelihood of conception.

After entering the vagina, sperm should leave it within a few minutes and move to the cervix. The fact that the vaginal environment is acidic, which is necessary to protect the female body from the entry of bacteria and viruses. However, the acidic environment quickly destroys sperm, if the sperm is in it for more than two minutes, it dies. According to statistics, only one out of 100 spermatozoa can leave the vagina and move into the cervix.

Therefore, it is very important that spermatozoa during ejaculation get as close to the cervix as possible, which is impossible in cases of anomalies such as hypospadias (the outer opening of the urethra is on the lower surface of the penis).

The cervix uteri contains special mucus, which, on the one hand, protects the sperm cells from the aggressive vaginal environment and, on the other hand, may prevent their further movement. The consistency of mucus depends on the hormonal status of the woman, and most of the time it is not permeable even for the healthiest and most mobile sperm cells. A few days before ovulation, the consistency of the mucus changes so that it is able to skip the sperm.

In some cases, cervical mucus may contain antibodies (proteins produced by the immune system to combat foreign substances that have entered the body) to sperm, which prevent sperm from passing through the cervical mucus even during ovulation.

Pathogenesis of male infertility

After passing the cervix, sperm gets into the uterus, and before it there is a dilemma – in which uterus to move on: right or left. Women have two fallopian tubes (one on each side), but only one of them comes out of the ovary every month. In this situation, the woman’s body comes to the aid of the sperm. In the period close to ovulation, due to hormonal effects of the uterine muscles on the side of ovulation begin to contract rhythmically, indicating the sperm to the correct opening of the fallopian tube.

The next stage for the sperm is the passage of the uterine tube opening. It is very small, with a diameter of only a few heads of sperm, so the sperm that move chaotically, will not be able to enter it. This stage is overcome only by spermatozoa with rapid and straightforward movement.

Once in the fallopian tube, sperm cells are in a fairly favorable environment, attached to the walls of the tube and waiting for the egg to come out. In this condition, they can be quite long – about 48 hours.

The output of an egg from an ovary is accompanied by an increase in temperature in the fallopian tube by 1-2 degrees, which serves as a signal for hyperactivation of sperm. They begin to move intensively with the tail, detach from the wall and move quickly towards the egg. At this stage, there are 6-8 sperm cells left, and they have a few hours to fertilize the egg, because its life span is very short.

Compared to the sperm, the egg is quite a large cell, the largest in the human body. After leaving the ovary, it is surrounded by a cloud of cells called follicular cells, through which sperm has to penetrate before it comes into contact with the egg surface. To pass through the follicular cells, spermatozoa must use the intense movement style (hyperactivation) that they used to separate themselves from the walls of the fallopian tube.