Male infertility


Male infertility

Description of male infertility

Fertility is a term that is defined as the ability to conceive a child.For women the ability to conceive a child it also adds the ability to give birth. Fertility in men during the entire 20th and 21st centuries decreases. The exact causes are not yet known, but is considered primarily on the effect of the full range of different chemicals, which are brought into food, water or the like.

Another definition of male infertility is the inability of a man to impregnate a woman in her most fertile days of the menstrual cycle that lasts longer than a year.

 

Risk factors for male infertility

Risk factors were determined by a number. As already mentioned above, infertility can manychemicals. Examples are chlorinated biphenyls, also is an alcohol (especially in excess) element lead. The suspicion are some drugs (potency etc.).

Another group of factors included influences that lead to heating of the testes. For proper growth and development of sperm is important because the temperature somewhat lower than human body temperature (optimum temperature is around 32 ° C instead of 36.5 ° C in the body). Men who wear tight underwear that heats the testicles are demonstrably less fertile. Men who work on the lap with laptop computers, and also men, who have a sedentary job (too are threatened by the driver).

Infertility may also cause testicular inflammation (e.g., mumps virus) and the like. All of the factors which can cause infertility, they are divided into three basic groups.

 

Prevention of male infertility

It is essential to respect for the overall healthy lifestyle: avoid smoking, alcohol, drugs, adhere to the principles of safe sex. A diet rich in vitamins (vitamin C, folic acid, B12) and elements such as zinc and the like. Plenty of movement, appropriate underwear, etc.

 

Causes of male infertility

Causes of male infertility can be divided according to the place of localization causes of infertility for three types

pretesticular causes

These are those in which the first cause is the insufficient development of male sex žláz- testes –hypogonadism. This may be caused by a variety of reasons – genetic variations – e.g. Klinefelter’s syndrome, which is caused by unnecessary X chomonozomem (sex gene) in cell karyotype man.Under physiological condition of a man has an X chromosome and a Y chromosome, if the X chromosomes more, it causes infertility.

Other causes may be, as already mentioned, chemicals, tight clothing, cycling, riding, etc.

testicular causes

the principal cause of the poor ejaculate in terms of the number of viable and motile sperm. Sperm can have a bad shape, composition, etc., Then we talk about teratospermia. Lack of sperm, then known as oligospermia. The complete absence of sperm in the ejaculate is called azoospermia.

Another cause may appoint a wide range: malignant tumors (eg. Seminomas), varicocele, hydrocele, infections, measles, malaria, unexplained failures.

Posttesticular causes

In these cases normal testicular function, however, the sperm will not get out of the body -Ie.obstruction of the vas deferens and the like.

To rank these causes obstruction of the vas deferens, the complete absence, inflammation of the prostate, erroneous mouth of the urethra, impotence and the like.

The quality of the ejaculate

Or ejaculate semen is a fluid that is released during ejaculation into the vagina sexual partner. This fluid consists of sperm, followed by a fluid which is formed in the seminal vesicles, prostate, Cowper’s glands and in the glands of the urethra.

Quantity of ejaculate after a few days of sexual abstinence around 2.5- 3.5 ml. Ejaculate contains a number of components, such as: sugar, fructose (1.5 to 6.5 mg / ml), as phosphorylcholine, ergothioneine, ascorbic acid, flavins, prostaglandins, zinc, acid phosphatase, fibrinolysin, etc.

Greatly depends on the amount of live and motile sperm. Quantity of quality sperm is constantly shrinking. It is reported that the average ejaculate containing 100 million sperm cells, wherein there is less than 20% abnormal forem.50% of men who are 20 to 40 000 000 sperm are infertile. If the number of sperm falls below 20 million, then virtually all are infertile.

It is interesting to say that the sperm move into the female’s reproductive tract rate of 3 mm / min.In half an hour to reach the fallopian tubes, where fertilization normally occurs.

Genetics

A certain group of men are infertile due to chromosomal abnormalities. For the lighting, it is necessary to mention the basic genetic aspects of sex.

The man has 23 pairs of chromosomes, of which 22 pairs are called. Autosomes and one pair is formed gonozomes (sex chromosomes). In humans, sex hormones referred to as X and Y. Sexing can be done by gene (eg. Yeasts), chromosomal (humans, birds, butterflies) and nongenetic factors (temperature at which a mature egg), as we see eg. In crocodiles. The presence of the two sex chromosomes X indicates that it will be genetically a woman. Combination of XY sex chromosomes, suggesting a genetic male sex.

One then produces gametes (sex cells that have half its chromosomes, thus have 23 chromosomes, one of which consists of X or Y chromosome). A woman is homogametic sex, ie. they form the same type of gametes (sex cells form a female only with the presence of sex chromosome X, because the Y chromosome does not). Man is then hetegogametické sex, because produces gametes with both X and Y chromosomes.

When there is fusion of gametes diploid zygote (already has 46 chromosomes). If the combination XX, then she is a woman, if XY, then it is a man. One X chromosome is absolutely essential for life (it contains important genes), but the woman would form twice more gene products (double gene jar), which would cause considerable problems for the functioning of cells.

Therefore occur in women for a so-called. X-inactivation, thus inactivating one X sex chromosome.The inactivated chromosome can then be found as Barr body, fused body, usually near the core.

On the basis of the sex genes and their products begins to differentiate morphologically and sex.Generally, within 6 weeks prenatal life are germs gonads that are formed in the so-called. Genital trench near the kidneys (obviously their embryo) completely identical and can not be mutually distinguished from each other. Embryo of the future gonads has its own cortex and medulla.

For genetic men in the 7th and 8th week of marrow produces testicle cortex is slowly disappearing.For further development it is important the formation of two types of cell populations: cells Sertoli and Leydig cells. Sertoli cells begin to produce Müller inhibiting substance (MIS acronym), which is important for removal of Müllerian duct (embryo female genital tract). Leydig cells producetestosterone, a male sex hormone.

The entire group of causes of infertility is caused by a chromosomal abnormality that results in the death of either individual or prejudicial to him in terms of its morphology and function of body organs, but can also produce bad sex cells that are viable and capable of fertilization.

One of the mechanisms of chromosomal abnormalities is the process of non-disjunction. This phenomenon indicates unequal distribution of genetic information in cell division. Previously, the cell divides into two daughter cells (a phenomenon called cytokinesis) must occur two cores, that has been distributed genetic information. Normally, the core is divided in a process called mitosis (has several stages, in one of them, the doubling of genetic information, so that the cell has at some point instead of 2n 4n – instead of two sets of chromosomes 4 sets of chromosomes).

The result of mitosis is then formation of two cores, each of which has two sady- 2n, which is totally physiological action. This applies to body cells. For the production of sex buněk- gametes but need more complex system, as it applies here that each gamete has only one set of chromosomes. Sperm has 23 chromosomes, the egg also has 23 chromosomes, so that when the connection is formed zygote which has 46 chromosomes – again physiological condition.

So it is necessary that the cells originated from cells 2n n (haploid cells), this is done by going called meiosis. In essence, we can say that meiosis represents two mitotic division behind. So from 2n cells originate 2 × 2n daughter cells (the first mitosis), and of those 2 × 2n then 4 × n (sperm).Egg sad part is excreted as so. Pole bodies, so there is only one egg, but man creates 4 sperm.

Finally we get to the problem of non-disjunction, that means the wrong chromosomes divide into daughter cells, so the cells can form where there is more sex chromosomes, cells, and some will not. Both of these mechanisms can cause infertility.

For a man it describes so. Dysgenesis seminiferous tubules – Klinefelter’s syndrome. This syndrome occurs in men who have sex chromosome one more than is necessary: they XXY. This implies the mental retardation, distinct morphology of the body, and defective construction seminiferous tubules, so the man is infertile.

But there are a number of syndromes in which there are abnormalities, not sex chromosomes. An example is the well-known syndrome Trisomy 21 (Down syndrome) in which the affected person found three chromosome 21 instead of two, as is conventional. Men with Down syndrome, in addition to characteristics such as mental retardation, simian crease the fingers, epikanty on the eyelids, malformations of the heart, a great risk of Alzheimer’s disease etc. are infertile.

Another syndrome is a syndrome ciliary dysgenesis, which is also known as Kartagener syndrome.This syndrome is characterized by defective sperm tail construction lacking the characteristic protein – dynein, which allows movement of sperm needed.

prolactinoma

Prolactin is one of the possible causes of infertility in both men and in women. Infertility arises here as a result of hormonal imbalance that occurs in the presence of prolactinoma.

Prolactinoma can be characterized as a pituitary adenoma (adenoma is basically a benign tumor that arises in hypofýze- pituitary gland, which produces and stores important control hormones that influence the production of hormones in the periphery (endocrine glands). The pituitary gland is the second highest Centre, regarding hormonal regulation. the highest position is hypothalamus.

The tumor is hormonally active, ie. that produces large amounts of the hormone prolactin. This output goes out feedback control mechanism, which is very well capable of preventing fluctuation in terms of changes in the concentration of hormones. Very important symptom, but by no means constant is called. Galactorrhoea – which is the production of milk in women mammary gland during lactation or outside production in men, but this is rare.

Prolactin decreases the level of a gonadotrophin releasing hormone, which is one of the control hormones. The result is hypogonadism (see above), which in women menstrual disturbances until its disappearance. Men are reflected reduced libido, erectile dysfunction to impotency, infertility and above.

Furthermore we talk about. Pseudoprolaktinomu which arises pituitary adenoma, but does not produce prolactin, but produces another hormone, which in turn disrupts hormonal imbalance, such as a lack of dopamine, which inhibits secretion of naturally prolactinoma.

 

Treatment of male infertility

It is somewhat difficult; it depends on the correct diagnosis of the causes of infertility. In case Posttesticular conditions may be surgical correction.

In the case of poor semen treatment is very difficult. Absence of sperm can be treated byapplication of hormones (HCG, FSH).

For infertile couples it offers the possibility of artificial insemination.

Other names: sterility, impotence in men, azoospermia, oligospermia, hypogonadism

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