The testicles or, in other words, the testes belong to the male internal genital organs. The structure of the testes has a dual function: the formation of sperm and hormone growth. These hormones give the man a characteristic masculine look, a low voice, the presence of facial hair. They also determine specific male behavior and mentality.
The normal size of the testicles is 3-4.5 cm and weighs 20-30 grams. They are in a bag of leather called the scrotum. The skin of the scrotum is pigmented, outside the septum between the testicles there is an embryonic suture, which can vary greatly in color from the scrotum. It has a huge amount of sebaceous and sweat glands, the allocation of which has a specific smell.
Already in the first months of fetal development, testicles begin to form. They are located next to the kidneys, and then they descend into the scrotum. The question arises, but what's the point in this transformation? It turns out very big. The fact is that for the development of sperm, a lower temperature is required - somewhere around 34 ° C. Naturally, such a temperature inside the body cannot be achieved, and just the right conditions for the formation of spermatozoa are maintained in the scrotum. Thus, men who have a sedentary lifestyle should get up from time to time so that the testicles are away from a hot body and cool.
The testicles are surrounded by a membrane and are separated from each other by a septum. They are hung on the spermatic cord, which, in turn, consists of the vas deferens, muscles, nerves, blood and lymph vessels. A muscle called cremaster, when contracted, pulls the testicle to the body, in a relaxed position, moves it away from the body. It seems to automatically maintain the temperature inside the scrotum. In warm conditions, they drop lower, and in cold conditions, on the contrary, they are pulled to the body. The scrotum is also an erogenous zone of a man.
The testicle has several supporting structures. For example, spermatozoa mature in the appendage within two weeks, where they acquire the necessary mobility. The structure of the testicles is as follows: under the protein membrane of the testis is the parenchyma. It consists of numerous lobules (from 250 to 300), which are filled with seminiferous tubules. In each lobule they are two or three, their length is 70-90 mm, they are folded. They consist of a spermatogenic epithelium, in which sperm are born.
The structure of the testicles is such that a component of the lobules is the connective tissue, which produces male hormones - testosterone. It turns out that the testes perform two functions - they are the gland of internal secretion, directing hormones directly into the blood, and at the same time, by the excretory gland, which removes sperm to the outside. The structure of the testicles is such that only sperm are formed in them. The liquid part of sperm is formed from the secrets of the prostate and seminal vesicles. The prostate gland is located next to the peritoneum, in case of its illness, the doctor gropes it through the rectum. It produces a fluid called prostate juice. In appearance, it is a white liquid with a characteristic odor, consisting almost entirely of protein.
Seminal vesicles are located above the prostate gland. This is a paired organ, its approximate size is 5x2x1 cm. Bubbles produce a yellowish liquid with increased viscosity, which promotes the movement of sperm.
As already mentioned, sperm maturation occurs in the epididymis, where they are stored. The structure of the male testicles also contains the seminiferous tubules, which, merging, form about 15 efferent tubules that flow into the epididymis.
Since the spermatozoa formed in the testes cannot move independently, their movement occurs due to increased pressure in the testicles themselves due to the formation of new sperm.
The vas deferens are a continuation of the epididymis. The advancement of sperm along the ejaculatory tract is carried out in the form of a wave-like contraction of the corresponding muscles.