Reproductive system of men and women

The main differences are due to the hormonal background, although both have the production of androgens and estrogens. Differences in the reproductive system of men and women are determined by the high constant secretion of the main male hormone testosterone. Estrogens are present in low concentrations. In women, cyclic estrogen production predominates in the hormonal status, androgens are produced insignificantly. But there is a higher commander over the hormones.

Why is there a division into boys and girls in utero? With the advent of genetics as a science, the answer is obvious. The egg cell has a set of chromosomes 23X, spermatozoa may contain 23X or 23Y. When merged, 46 XX is obtained, and then development proceeds according to the female type. Or 46XY and this is the command to form the male reproductive system.

Let's look inside the fertilized egg

The external genitalia begin to form from 6-7 weeks. The genital tubercle and urethral fissure appear. On the sides of them, two folds are laid - urethral and labioscrotal. These are prototypes of the labia majora or scrotum of the external female and male genitalia. From the 8th week, a penis begins to form from the genital tubercle, the urethral fissure closes, and the scrotum appears from the labioscrotal fold. At this time, it is already clear that the embryo will have anatomically male genital organs.

The internal genital organs are ready to start building on one or another basis at 3-4 weeks. The primary gonad is laid and the Wolffian and Müllerian ducts are formed. One and the same embryo has both; at this period of development, gender is not determined. From week 7, the primary gonad is transformed into testicles. From the 9th week, testosterone is formed in special cells (Leydig cells), under the influence of which an epididymis, seminal vesicles are formed from the wolf ducts over a period of just over a month. From 14 weeks, the anatomy of the fetus is formed according to gender. At week 8, minor changes in the urethral fissure occur, the genital tubercle passes into the clitoris.

Baby is born

Gone are the days when pregnant women only after going through childbirth, found out the sex of their child. Having cut the umbilical cord, the midwife showed the newborn to the mother and asked to name the gender. Someone with delight, and someone with disappointment, stated the fact of the baby's gender.

Now, going to the hospital, a pregnant woman almost always knows the gender of the unborn child.

At birth, the only external difference between boys and girls is the genitals. A full-term boy has a penis, the approximate length of which is 3 cm, testicles in the form of small balls are determined in the scrotum. One testicle may be slightly larger than the other.

Why did the male testicles, unlike the female ovaries, not find a place in the pelvis? Male testicles are very sensitive to temperature. When they overheat, diseases can occur that subsequently disrupt the process of spermatogenesis. With hypothermia, the skin of the scrotum shrinks, the testicles, as it were, are pulled up to a warmer body. Often there is a children's phimosis, the foreskin does not make it possible to expose the head. This usually resolves at 3 to 4 years of age. An empty scrotum can be with prematurity or with chromosomal and hereditary diseases. At discharge, the pediatrician of the maternity hospital will explain whether it is necessary to sound the alarm and when it is better to contact a specialist.

In newborn girls born at term, the small labia are covered with large ones. The entrance to the vagina is covered by the hymen.

It is worth noting that the girl's ovaries contain hundreds of thousands of primordial follicles, a kind of strategic reserve of future eggs. The ovaries of girls, like the testicles of boys, are not the same in size, the right one is slightly larger. The anatomy of the uterus and appendages of a girl is different from that of an adult woman. The ratio of the length of the body of the uterus and the cervix in the girl is shifted in favor of the latter. Shortly after birth, some girls may have a sexual crisis. Bloody discharge appears from the vagina. This is not a disease, this is how the body of a newborn reacts to the cessation of the influence of maternal hormones. Of the diseases of the genital area during the neonatal period and childhood, developmental anomalies, vulvitis, balanoposthitis can occur. Children's phimosis can turn into pathological. Symptoms of early puberty may appear. Boys may experience dropsy of the testicle.

Puberty

Puberty in girls begins earlier than in boys by about 2 years. Under the action of GnRH produced in the hypothalamus, the pituitary gland begins to produce its own hormones that affect body growth, the characteristic distribution of fat, the formation of the breast and pelvis. Androgens, produced mainly by the adrenal glands of the girl, are responsible for the nature of the hair, which begins with the pubis and has the shape of an inverted triangle. Then the hair moves to the armpits.

Pituitary hormones stimulate the cyclic production of sex hormones in the ovaries.Menarche occurs at 12-14 years of age. Estrogens cause the growth of the uterus, its ratio to the neck is leveled, the follicle begins to mature in the ovary. Having reached maturity, the follicle bursts, an egg is born. The process is repeated cyclically, the menstrual cycle in the period of formation may be irregular, anovulatory. But from that time on, a girl can conceive a child through sexual contact, but psychologically, the readiness for bearing comes later, by the age of 17-18.

The same GnRH hormones, through the secretion of gonadotropic hormones from the pituitary gland, cause spasmodic body growth in boys, an increase in the size of the testicles, and the production of testosterone.

The penis grows, pubic hair appears, initially in the form of an inverted triangle, which turns into a rhombus. Hair covers the thighs, chest. forearms, shins, shoulders. Soon a youthful fluff appears on the upper lip, and a little later a beard begins to grow. A teenager's voice breaks, the larynx changes with the formation of an Adam's apple inherent only in men. Under the influence of testosterone, libido increases, nocturnal ejaculations of wet dreams occur, the penis spontaneously undergoes an erection. A young man during this period is able to become a father, but just like a girl, this is only at the level of physiology, there is no psychological readiness for childbearing.

The structure of the genitals becomes similar to the genitals of an adult male. The process of growing up is completed by the age of 17-18.

What disease of the genital area prevails at this age? In the first place among representatives of both sexes are inflammatory diseases, often STDs and venereal diseases. Ease and irresponsibility in choosing partners, unprotected sex, non-compliance with intimate hygiene causes diseases at this age. And also an unplanned pregnancy with the ensuing consequences. In adolescents, vascular diseases of the testicles (varicocele) can occur, which are treated surgically. Girls during the formation of menstruation have juvenile bleeding, sometimes requiring hospitalization.

An adult man, an adult woman

With the variability in the development of the reproductive system in men and women, there are basic signs of confirmation of sexual maturity. Male genital organs penis and scrotum with testicles. This is where spermatozoa are produced. Above them are the epididymis. Paired vas deferens pass through the inguinal canals. The second heart of a man, as they themselves call the prostate, is located just below the bladder. It produces prostatic juice, which thins the sperm. The ejaculate contains fluid from the seminal vesicles. The detailed composition of sperm is as follows:

• Prostate juice 30%
• Seminal vesicle fluid 65%;
• Sperms 5%.

The penis consists of cavernous bodies, which at the moment of sexual desire are filled with blood and provide an erection. This is the anatomy of the penis. Distinguish base, trunk and head. The head has a thickening along the edge, under which there is a groove called the coronal. This area is important when carrying out hygiene procedures. The head is connected to the trunk of the penis with the help of a bridle, in the top it is covered with a skin fold (foreskin), easily shifted and exposing the head. The foreskin protects the head, rich in nerve endings, from injuries and infections, but at the same time, smegma accumulates in the preputial space, which is a breeding ground for microbes. On the head is the external opening of the urethra of the urethra, which in a man plays the role of not only excreting urine, but also serves to pass the sperm.

The size of the penis of an adult male is individual, the average size with a maximum erection is 12-18 cm.

In addition to the penis, the external genital organs include the scrotum, the skin pouch. The scrotum is also supplied with a large number of nerve endings, sebaceous and sweat glands, hair follicles are present. The internal genital organs of the testicles are located inside this skin sac, their sizes are individual, on average 4-6 cm long and 2-4 cm wide. The right and left testicles may differ in size, one of them, more often the left one, is lowered. The fertilizing ability of spermatozoa depends on many factors:

• Sperm counts;
• Sperm counts;
• Progressively actively motile sperm counts;
• Abnormal germ cell numbers.

The anatomy of the female genital organs also involves their division into external and internal. The external organs are formed by the labia majora. In their lower third are large glands of the vestibule, the secret of which moisturizes the vaginal mucosa. The labia minora in the region of the anterior commissure form the clitoris, an organ similar to the penis. Stimulation of the clitoris leads to sexual arousal. A little below it is the opening of the urethra.

The entrance to the vagina is covered by the hymen, which is torn or stretched during the first sexual contact.

The vagina is a folded bag, capable of stretching, at the top of its dome is the cervix. In the center of it is the cervical canal, through which menstrual blood flows and spermatozoa penetrate. The uterus is a hollow muscular organ, the size of a matchbox, but increases its mass up to 2 kg during pregnancy. The inner layer of the uterus, the endometrium, is shed monthly in the absence of pregnancy. It is in them that the egg meets the spermatozoa and fertilization takes place. The process is called ovulation. During this period, men face such problems:

• Inflammatory diseases of the genital organs;
• Erectile dysfunction;
• Impaired spermatogenesis;
• Prostatic hyperplasia;
• Oncology testicles, penis, prostate.

In addition to inflammatory diseases, women may have menstrual irregularities, uterine bleeding, uterine fibroids and endometriosis, and oncological diseases.