Body processes

Spermatogenesis – Function, Task & Diseases

Spermatogenesis

The term spermatogenesis refers to the formation of sperm. It begins with the onset of puberty and is a prerequisite for reproduction .

What is spermatogenesis?

Male germ cells are formed during spermatogenesis. These are known as sperm . Spermatogenesis takes place in the sexually mature testicles . Here the sperm cells go through various stages of development and finally mature into sperm.

Spermatogenesis lasts an average of 64 days and is under the control of the pituitary and hypothalamus . Disorders in spermatogenesis can impair male fertility.

function & task

Even before birth , spermatogonia form from the stem cells of the testicles. This production cycle continues during puberty. Spermatogonia are primordial sperm cells. They arise from the primordial germ cells when these have migrated into the testicles of the unborn child while they are still in the womb.

The spermatogonia arise through a mitotic cell division of these primordial sex cells. The primordial sex cells, also called gonocytes, are located in the seminiferous tubules. Type A spermatogonia are formed during division. Type B spermatogonia are formed by further division from type A spermatogonia. One of these daughter cells remains with the original spermatogonia. This ensures that spermatocytes can be reproduced throughout life.

The B spermatogonia are connected by processes and form groups. The groups go through the different stages of spermatogenesis together. They migrate through what is known as the blood-testicular barrier in the direction of the seminiferous tubules. The blood-testicular barrier lies in the seminiferous tubules of the testicle. It is impermeable to large proteins and immune cells. This distinction is important because spermatocytes have antigenic properties. This means that they might be repelled by their own immune system .

Once the B spermatogonia have arrived in the seminiferous tubules, they are referred to as first-order spermatocytes. In the testicular tubules they undergo the first meiotic division. During this meiosis , second-order spermatocytes are formed by haploidization. These are also called secondary spermatocytes.

The second meiosis directly follows the first meiosis. During meiosis II, two spermatids are formed. The spermatids are the smallest cells of the germinal epithelium. They are significantly smaller than the spermatocytes. Four spermatids are formed from one spermatocyte during spermatogenesis.

In the last step of spermatogenesis, in spermiogenesis , these spermatids mature into sperm. The nucleus of the spermatids condenses and there is also a loss of cell plasma. The spermatids also form the typical tail. This is also called kinocilia. Furthermore, the acrosome develops from the Golgi region during spermiogenesis. The acrosome is the head cap of the sperm. It covers the head and serves to penetrate the egg cell . Four spermatozoa are formed from one spermatogonium as part of spermiogenesis and spermatogenesis. Two of them carry an X chromosome and two carry a Y chromosome.

The complete process of spermatogenesis takes 64 days. The first multiplication of spermatogonia lasts 16 days. Meiosis I lasts 24 days and meiosis II lasts only a few hours. Sperm maturation during spermiogenesis lasts 24 days. At the end of spermatogenesis is the sperm, which serves to fertilize the female egg.

Diseases & Ailments

Disorders of spermatogenesis can have different causes. Natural fertility decreases with age. From about the age of 40, the sperm cell density decreases. The spermatozoa are then no longer as mobile. Errors occur more and more frequently during the division of the meiosis. Thus, the number of abnormal spermatozoa increases. Chromosomal changes can also be observed more frequently.

The spermatogenesis can also be disturbed due to genetic abnormalities. If there are no sperm cells in the ejaculate , this is referred to as azoospermia . Azoospermia is a typical symptom of Klinefelter syndrome . It is an abnormality that leads to hypofunction of the gonads.

Klinefelter syndrome is hypergonadotropic hypogonadism . If the disorder is at the level of the pituitary or the hypothalamus, it is called hypogonadotropic hypogonadism. Typical diseases are Kallmann syndrome or pituitary adenoma . Damage to the anterior pituitary gland in the event of hemochromatosis can also affect spermatogenesis and thus impair sperm formation.

The spermatogenesis and thus also the quality of the sperm is also determined by one’s own everyday behavior. For example, malnutrition can lead to a decrease in sperm count. An incomplete and nutrient-poor diet with lots of saturated fatty acids , sweets, ready meals and breaded meals not only leads to a lack of micronutrients, but also to restricted spermatogenesis. The same applies to the regular consumption of alcohol , coffee and tobacco .

Alcohol consumption in particular has a negative effect on sperm development. Due to alcohol-related liver damage , sex hormones in the organism can no longer be completely broken down. This leads to hormonal imbalances at the hypothalamic-pituitary level. The quality of the sperm cells deteriorates and the sperm cell density decreases. In return, the proportion of malformed sperm cells increases.

Smoking reduces sperm motility. In addition, the DNA of smokers is less stable than the DNA of non-smokers. X-ray radiation, ionizing radiation, heat, various drugs and environmental toxins also damage spermatogenesis.

Since spermatogenesis takes place in the testicles, diseases of the testicles can also impede sperm formation. Underdevelopment of the testicular tissue, testicular injuries, infection of the prostate , undescended testicles or testicular inflammation caused by mumps can reduce the quality and quantity of sperm.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.