Location of the gonads. Male and female gonads

The human body is a very complex structure in which everything is interconnected. The reproductive system provides human reproductive function. It is controlled by the endocrine system, which produces various hormones, each of which regulates certain processes. The endocrine system consists of a collection of different glands, each of which produces hormones. Different glands are interconnected. The most important is the pituitary gland, which controls the entire human body; the importance of the pituitary gland is difficult to overestimate. The regulation of the endocrine function of the gonads is carried out by the pituitary gland.

Sex hormones

Gonadal hormones are divided into male and female. Male sex hormones are androgens. Among them, the most significant for the male body is testosterone. Also, small amounts of estrogens are produced in the body of men. This process is carried out through androgen metabolism.

Female hormones are estrogens and progestins. Progestins include several hormones. In small quantities, the female body also produces male hormones (androgens).

Essentially, the same hormones are present in the body of both sexes. But some of them predominate in the body of men, while others predominate in the body of women. If any hormonal disturbances occur, the human body may cease to perform its sexual function. In this case, various serious diseases develop. If a hormonal imbalance occurs during puberty in a teenager, the ability to perform reproductive functions may be lost. Various types of sexual disorders also arise.

Functions of the gonads

Men and women have different sex glands, but they perform the same functions. In men, the gonads are the seminal glands, and in women they are represented by the ovaries. Male organs produce germ cells (spermatozoons), with the help of which fertilization of female germ cells - eggs is carried out. In this way, the exocrine function of germ cells is carried out.

The endocrine function of the gonads is to produce female and male sex hormones. Hormones enter immediately into the human blood. The performance of sexual function and the general condition of the body depend on their level.

Characteristics of hormones

Male hormones androgens ensure the maturation of sperm and their motor ability. Androgens affect protein synthesis in tissues and metabolism in the male body. Androgens also have a connection with the central nervous system, they affect behavioral reactions and higher nervous activity. If a man is castrated, this is accompanied by various disturbances in the functioning of the nervous system. Mental and emotional abnormalities occur in a man.

Estrogens affect the growth and development of a woman’s genital organs and mammary glands. They stimulate the formation of secondary female sexual characteristics and sexual reflexes. Under the influence of estrogen, the uterine muscles contract, and the uterus is sensitive to the hormone oxytocin.

The internal genital organs are located in the pelvis, these include:

sex gland - ovary,
uterus,
the fallopian tubes,
vagina.

The external genitalia include formations of the so-called pudendal region:

large private lips,
small pudendal lips,
clitoris.

Ovary - a paired gland, which is located in the small pelvis on the posterior surface of the broad ligaments of the uterus. Externally, the ovary is covered with a connective tissue membrane, under which there is cortical substance, and deeper - cerebral substance. The ovarian cortex contains vesicles of different sizes, or follicles, in each of which a female reproductive cell (ovum) develops, and in the medulla - vessels and nerves. The formation of follicles is completed at the time of birth. 200-300 thousand of them are laid, by the age of 10 there are 3-4 times fewer of them, by the beginning of puberty there are about 15 thousand left, of which only 300-400 mature.

Unlike the male gonads, the ovaries do not have ducts. A mature egg is released from the follicle when its wall ruptures. Together with the flowing clear liquid, the egg ends up on the surface of the ovary, in the peritoneal cavity, from where it is drawn into the lumen of the fallopian tube. At the site of the burst follicle, a corpus luteum– endocrine gland. When the egg is not fertilized, the corpus luteum is called false and undergoes reverse development. When the egg is fertilized and pregnancy occurs, the corpus luteum is called true, it grows and persists throughout pregnancy.

Uterus lies in the pelvis between the bladder and rectum. In the uterus there are:

bottom (top),
body,
neck (bottom).

The slit-like cavity of the uterus from the bottom communicates with the right and left fallopian tubes, and from the cervix it continues into the cervical canal, which ends with an opening in the vagina. On the uterus there are cystic and intestinal surfaces, right and left edges.

The wall of the uterus has:

mucous membrane (endometrium),
muscular (myometrium),
serous (perimeter) membrane.

The mucous membrane contains glands that secrete mucous fluid and blood vessels into the uterine cavity. The fertilized egg is immersed here. Outside of pregnancy, the surface layer of the mucous membrane regularly, after 24-28 days, peels off and is rejected along with the egg entering the uterine cavity. The ruptured vessels of the mucous membrane bleed. This type of uterine bleeding is called menstruation and lasts 3–4 days. The time from the beginning of one menstruation to the beginning of the next is called menstrual cycle. At this time, complex structural and functional changes occur in the woman’s body.

Oviduct - paired formations 10–12 cm long, through which the egg moves into the uterus. Each tube lies at the top of the broad ligament of the uterus and has two openings: one opens into the uterus, the other opens into the peritoneal cavity near the ovary. The wall of the tube consists of a mucous membrane covered with ciliated epithelium, a muscular and serous membrane. Fluctuations of the cilia of the epithelium and contractions of the muscular layer contribute to the movement of the egg through the tube.

Vagina It is a tube about 8 cm long, the front and back walls of which are flattened. At the top the tube communicates with the cervix, and at the bottom it opens into the pudendal area. Before entering this area, the vagina, like the urethra, pierces the thickness of the urogenital diaphragm. The rectum lies behind the vagina and the urethra lies in front. The inner surface of the vagina is covered with a mucous membrane, forming a fold in the pudendal area called hymen, then there is the muscular layer and then the connective tissue, in which there are many elastic fibers.

Male genitals are divided into internal and external. Internal ones include:

sex gland - testicle,
epididymis,
seminal vesicle,
prostate,
bulbo-urethral glands.

The external genitalia include:

penis,
scrotum.

Testicle – paired gland, which is located in abdominal cavity, and then descends into the scrotum through the inguinal canal. The testicle has several membranes: serous, has two layers: parietal and visceral, between which a serous testicular cavity is formed with a small amount of serous fluid. The visceral layer covers the tunica albuginea, adjacent to the substance of the testicle, and forms septa inside this substance that divide it into lobules. There are 150–250 lobules in the testicle. Each lobule contains tubules, in the initial part of which the formation of male germ cells occurs – spermatozoa

Epididymis located along the superior posterior edge of the testicle and has:

head,
body,
tail.

The efferent tubules of the testicle in the epididymis, connecting, form epididymal duct, which serves to conduct sperm into the vas deferens. The vas deferens emerges into the spermatic cord, where besides him are arteries, veins, lymphatic vessels and nerves, surrounded by shells. The spermatic cord, in the form of a cord on which the testicle and epididymis are suspended, rises up and passes through the inguinal canal. The vas deferens, having separated from the cord, runs along the side wall of the pelvis to the bottom of the bladder, where it connects with the excretory duct of the seminal vesicles.

Seminal vesicle adjacent to the end of the vas deferens. The excretory duct of the vesicle converges at an acute angle with the vas deferens. The seminal vesicle contains a fluid that is secreted by the mucous membrane and affects sperm motility.

Prostate (unpaired organ) is located under the bottom of the bladder in such a way that it covers the beginning of the urethra. The prostate gland contains glandular elements and smooth muscle fibers. The secretion of the gland flows through small ducts into urethra and joins the seed that enters here through the ejaculatory ducts. The smooth muscle tissue of the gland helps to squeeze secretions out of the gland and narrow the urethra, i.e., retain urine in the bladder while semen passes through the urethra.

Penis comprises:

root,
bodies,
heads.

The skin covering the head is called foreskin. Two lie longitudinally corpus cavernosum and one corpus spongiosum, passing into the head of the penis. The spongy part of the urethra passes through the corpus spongiosum. The three parts of the male urethra (prostatic, membranous and spongy) serve to remove urine and semen.

Scrotum – the skin-muscular sac where the testicles are located. The skin of the scrotum is thin, folded, with a large number of sweat and sebaceous glands. Under the skin is a fleshy membrane containing bundles of smooth muscle tissue. The scrotum is divided by a septum into two sections, each of which contains a testicle.

Sex glands belong to the glands of mixed secretion. Male gonad is the testis (testicle). It has the shape of a somewhat compressed ellipsoid. Testes- this is the place where the process of spermatogenesis occurs, as a result of which sperm are formed. Male sex hormones are synthesized in the testes. Wall The convoluted tubule consists of two types of cells: those that form sperm and those that participate in the nutrition of sperm. Sperm enter the epididymis through the efferent tubules and then into the vas deferens. Both vas deferens pass into the ejaculatory ducts, which enter this gland, pierce it and open into the urethra.

In the female reproductive glands– ovaries – the process of egg formation occurs – oogenesis(ovogenesis).

In women, the sexual cycle manifests itself in menstruation. The first menstruation appears after the maturation of the first egg, the bursting of the Graafian vesicle and the development of the corpus luteum. The sexual cycle lasts on average 28 days. It is divided into 4 periods:

restoration of the uterine mucosa within 7–8 days, a period of rest;
proliferation of the uterine mucosa and its enlargement for 7–8 days, preovulation, caused by increased secretion of folliculotropic hormone of the pituitary gland and estrogens;
secretory - release of a secretion rich in mucus and glycogen in the uterine mucosa, corresponding to the maturation and rupture of the Graafian vesicle, ovulation;
rejection, or post-ovulation, lasting an average of 3–5 days, during which the uterus contracts tonically, its mucous membrane is torn off in small pieces and 50–150 ml of blood is released.

The last period occurs in the absence of fertilization.

Male and female sex hormones are produced in approximately equal quantities in girls and boys. By the time they reach puberty, girls produce several times more sex hormones than boys. In young men, the secretion of male sex hormones increases. Precocious puberty is inhibited by the thymus gland, which functions as an endocrine gland until puberty.

Male sex hormones - androgens(testosterone, androstenediol, etc.) are formed in Leydig cells located in the interstitial tissue of the testes and in the spermatogenic epithelium. Thanks to testosterone and its derivative androsterone, the following occurs:

development of the reproductive apparatus and growth of the genital organs;
development of secondary sexual characteristics: deepening of the voice, changes in physique, appearance of hair on the face and body;
affect the level of protein and carbohydrate metabolism, for example, they reduce the synthesis of glycogen in the liver.

Female sex hormones - estrogens(estrol, estriol and estradiol) are regulators of the ovarian-menstrual cycle, and when pregnancy occurs, regulators of its normal course. Estrogens influence:

development of genital organs;
egg production;
determine the preparation of eggs for fertilization, the uterus for pregnancy, and the mammary glands for feeding a child;
ensure intrauterine development at all stages.

Estrogens increase glycogen synthesis in the liver and fat deposition in the body. Androgens and estrogens affect bone growth, practically stopping it.

A woman’s body has sex glands - this is a well-known fact.

But not everyone knows how many of them, as they are called. Each female reproductive gland is represented by a pair of organs.

What are the female reproductive glands called?

Surprisingly, anatomy experts counted only 2 types of gonads in women - the ovaries and Bartholin's glands. Each species has a special structure and unique functions in the body, which will be discussed below.

Structure

Healthy ovaries of an adult woman weigh only 5 to 10 grams, length - from 30 to 55 mm, and width - no more than 16-31 mm.

These are blue-pink organs, each of which is located in a special ovarian cavity and is attached to the uterus by ligaments.

The ovaries are quite complex and resemble the well-known nesting doll. The structure of this organ includes several layers.

The upper one is lined with cells called germinal epithelium. Beneath it is a dense and elastic stroma. And then there is the parenchyma, which consists of two layers. Inside it there is a loose substance, which is penetrated by many lymphatic and blood vessels. The next layer is a substance that is considered an incubator for the follicles.

It is here that the vesicles with the young egg are contained, as well as the follicles that are in the maturation stage. A mature follicle is a completely independent endocrine unit, because it produces hormones. Each vial containing the egg ruptures in due course, releasing it. A yellow body appears in place of the bubble.

Ovaries in women

The second pair of female reproductive glands, after the ovaries, are the Bartholin glands, which are located on the labia, to the right and left of the entrance to the vagina, and are structures of external secretion.

The volume of the gland is no more than 2 cm. The duct of the gland has the same length and exits at two points of the female labia minora. The structure of these glands is similar to those in men, only they are called bulbourethral. Each of the Bartholin glands is characterized by a tubular-alveolar structure and consists of several lobules.

The peculiarity of external secretion is that the product (“secret”) produced by the organ is not excreted into the body, but outside it.

The sweat, sebaceous and salivary glands work on the same principle. It is noteworthy that the external secretion organs are not part of the endocrine system.

Functions of the female reproductive glands

The ovaries play an important role in the body of a mature woman:

responsible for the production of sex hormones;
stimulate the formation of eggs.

The function of the ovaries during childbearing age is carried out strictly in cycles, each of which averages about 30 days and is called menstrual.

On the very first day of the cycle, one of four hundred thousand follicles matures, each of which is a tiny endocrine gland capable of producing female sex hormones.

Ovulation occurs in the middle of the cycle. By this time, the follicle has completely matured, its membrane ruptures, releasing an egg that is completely ready for possible fertilization. It moves into the uterus through the fallopian tubes.

During this period, the corpus luteum is formed, the function of which is the synthesis of its own hormone, which is useful for bearing a child in the event of pregnancy. If conception does not occur, the corpus luteum becomes white during the process of scarring, and a new follicle takes its place to soon again give the woman an egg.

As for the work of the Bartholin glands, it is devoted to two circumstances - sexual intercourse and childbirth. When aroused during sexual intercourse, colorless mucus is released from the ducts of these glands, which:

envelops the vagina to make sexual intercourse painless;
protects the mucous membranes of the external genitalia from drying out and minor injuries;
moisturizing, stretches the birth canal, protecting against ruptures and making the birth process easier for the child.

Breast cancer is the most common diagnosis in female oncology. may not be detected immediately, but there is no need to panic, the disease can be treated.

You can read about the reasons for increased dihydrotestosterone in the blood in women.

Solitary cyst of the mammary gland - signs and methods of treatment - topic.

Development

A woman’s gonads are formed and begin their formation at the stage of intrauterine development.

After the birth of a girl, the growth and further development of her gonads continues throughout childhood, and its main phase occurs during her puberty.

This complex process takes place under the “guidance” of the female sex hormones estrogen, which are produced by the ovaries. Estrogens are under the control of special pituitary hormones - follicle-stimulating hormone (FSH) and lutein-stimulating hormone (LH). They give rise to pubertal development, which lasts in the age range from 7 to 17-18 years.

This long process occurs in several stages:

7-9 years old. The ovaries almost do not work at this time, a minimal amount of estrogen is released. But with regularity of 5-7 days, random production of LH and FSH occurs.
10-13 years old. LH and FSH already work in a certain order, with FSH playing the main role. Estrogens promote the growth of mammary glands, age-related changes in the composition of the vaginal flora, and hair growth in the pubic part of the body. As a rule, it is at this age that the first menstruation comes.
14-17 years old. The secretion of LH increases, the mammary glands look fully formed, female-type hair growth is clearly visible, and the figure takes on feminine contours. By this time, the girl already has a normal, regular monthly cycle.

Ovarian hormones and their special role in the normal functioning of the woman’s body

The ovaries produce hormones on which the reproductive function of the female body depends, and not only.

Steroid hormones produced by the ovaries are divided into three groups: estrogens, gestagens, androgens.

Each group includes a list of individual hormones. The amount of steroids and their group ratio is determined by age and the phase of the menstrual cycle.

Estrogens. They have a powerful effect on the genitals, which depends on the quantitative value of the hormone level:

small and medium doses contribute to the development of female ovaries and the timely maturation of follicles in them;
large ones - suppress the ovulation process;
excessive - provoke atrophic transformations in the ovaries.

The effect of estrogens is not limited to the effect on the reproductive system.

stimulate metabolism;
promote the proper development of muscle tissue;
influence the formation of fatty acids,
reduce cholesterol levels;
affect the functioning of other organs and systems.

Gestagens. The main gestagen is progesterone, which controls the processes that make conception possible. It ensures the survival of the egg as it moves through the fallopian tubes, and also supports the development of pregnancy during the first three months. In addition, it suppresses spontaneous uterine contractions, regardless of the fact of pregnancy. In the body of a woman carrying a child, gestagens, together with estrogens, neutralize the effects of oxytocin and adrenaline on the uterus, preventing the onset of the process of premature birth.
Androgens. Their functions in the female body are much more modest than those of estrogens and androgens, but disturbances in the level of male sex hormones in the fair sex cause disorders such as disruption of the monthly cycle and problems with childbirth. Androgens are actively involved in the formation of fat, water and protein metabolism.

Progestins, like estrogens, affect metabolism. They are able to stimulate the production of gastric juice and reduce the volume of bile produced, affecting other processes in the body.

The importance of the gonads in the female body cannot be overestimated, since the normal functioning of the organs and systems of the body, and therefore the health and well-being of a woman, depends on the hormones they produce.

Video on the topic

The main sex glands of the female body are the ovaries. Their function is to ensure the normal formation of the egg and prepare it for fertilization. In addition, they are sources of two important female hormones - estrogen and progesterone, which affect the genital organs, form secondary sexual characteristics, and participate in the formation of the embryo.

Structure of the female reproductive glands

The ovaries are paired organs that are located on the posterior layer of the broad ligament of the uterus and on the sides of it. The obligatory structural unit of the gland is the follicle. Inside each of them there is an egg, which is surrounded by follicular cells. As follicles develop, the number of these cells increases and new membranes are added.

The following follicle transformations are necessary for normal egg maturation:

Successive stages of follicle maturation	Structural features
Primordial	Centrally located egg surrounded by a single layer of follicular cells
Primary	A zona pellucida appears around the egg, and the follicular cells begin to “sit” on the lamina (basal membrane)
Secondary	The number of follicular cells increases significantly. Outside of them, a new shell is formed - the theca. Estrogen cavities appear
Tertiary (mature)	The egg moves to one of the poles of the follicle, due to its intensive reproduction
Corpus luteum	The remaining part of the follicle after it ruptures and the woman’s reproductive cell exits into the fallopian tubes

Functioning of the ovaries

The entire physiology of these glands is entirely subject to endocrine regulation. Two important hormones control the development of follicles: follicle-stimulating hormone (FSH) and luteinizing hormone (LSH). These active substances are released from the anterior pituitary gland, located in the brain. Their active secretion begins from 9-12 years, which leads to the inclusion of a normal monthly cycle between 11 and 15 years. This period of life is called puberty or puberty.

All processes of transformation of the main structural elements of the ovaries described above occur during the menstrual cycle for 28 days. It consists of three phases:

Phases	Name	Description
1	Follicular, or premenstrual	During this period, under the influence of FSH and LH (mostly the former), there is a proliferation of follicular cells that synthesize estrogen . Then a new shell is formed - the theca. Its cells contain the main male androgen - testosterone. But it is converted into estrogens under the action of the aromatase enzyme. Thus, the concentration of the latter becomes very high, which further stimulates the production of FSH and LH. Because of this, the follicle grows greatly, which leads to its rupture. The duration of this period is from 1 to 12 days
2	Ovulation	In the middle of the cycle, 13-14 days after the rupture of the follicle, the release of the egg into the fallopian tubes is observed, where fertilization should occur. A prerequisite for the implementation of this process is a peak increase in estrogen and LH levels
3	Luteinizing	After ovulation, the remaining cells of the theca and follicles double in size and are filled with lipid inclusions, thereby forming the corpus luteum. Its creation occurs under the influence of LH. The main hormone secreted by this formation is called progesterone. . If fertilization does not occur, then the luteal body degenerates and is replaced by a white one, which resolves after a month. If the fusion of the egg with the sperm is completed, then the corpus luteum of pregnancy is formed.

It is important to understand that transformation occurs in many follicles, but only one dominant one undergoes ovulation. Consequently, a single egg enters the fallopian tubes. In the remaining follicles, the phenomenon of atresia (reverse development) occurs and they are called atretic.

The importance of estrogens

Every person's body contains both female and male sex hormones. In women, estrogens significantly predominate, which are responsible for the formation of secondary sexual characteristics.

Under their influence, girls and young women experience the following changes:

Tissues, organs and systems	Description
Reproductive system	Enlargement of the uterus, fallopian tubes, ovaries, vagina and labia minora. Fat deposits appear on the pubic area. The single-layer vaginal epithelium is replaced with a multilayer one, which prevents the development of infection, unlike in childhood. Stimulates the growth of epithelial cells and endometrial glands of the uterus after menstruation
Mammary gland	The formation of this body is initiated. The female breast is enlarged and shaped
Skeleton	Estrogens contribute to its increase, so during puberty girls begin to grow rapidly. Unlike testosterone, these hormones are more intensively involved in closing bone growth zones. This causes women to stop growing earlier than men.
Fat fiber	Increase the formation and deposition of fat in it, especially on the hips and buttocks, forming the characteristic features of a female figure
Skin and hair	They improve blood circulation, which makes the dermis smooth and soft, in contrast to the rough skin of men. Stimulates pubic and armpit hair growth.

Since the growth of follicles and, accordingly, an increase in estrogen levels occurs during puberty, these signs begin to appear during this period.

Sex glands - location, structure, functions.

The sex glands (testis and ovary) are the site of formation of sex cells and also release sex hormones into the blood. The main biological effect of these hormones is to ensure the normal functioning of the reproductive function.

Testicle, testis, is a paired organ of the male reproductive system located in the scrotum. In its parenchyma, in addition to the formation of sperm, the synthesis of male sex hormones - androgens (testosterone) occurs. These hormones are synthesized by Leydig cells located in the mediastinum of the testicle. Androgens ensure the development of the genital organs and the formation of secondary sexual characteristics according to the male type (physique, hair growth pattern and timbre of voice, activation of skeletal muscle growth, distribution of subcutaneous fatty tissue and regulation of sperm maturation). At the same time, androgens have a pronounced anabolic effect, increasing the activity of plastic metabolism.

Ovary, ovarium - a paired female reproductive gland located in the pelvic cavity between the leaves of the broad ligament of the uterus. It consists of cortex and medulla. At the time of birth, there are 400 - 500 thousand primary follicles in the cortex. During puberty and puberty (from 10 -12 to 45 -55 years), some primary follicles begin to increase in size and produce hormones. Such follicles are called secondary or maturing. During the generative period in women, only 400 - 500 follicles mature. The frequency of follicle maturation is on average one follicle every 28 days (from 21 to 35 days), this is the duration of the menstrual cycle. The mature follicle is called the Graafian vesicle. On the 14th day of the menstrual cycle, the Graafian vesicle ruptures - ovulation, in which a mature egg is released into the peritoneal cavity. In place of the follicle that ruptured after ovulation, the so-called corpus luteum develops - a temporary additional endocrine gland that produces gestagens (progesterone) - the hormone for maintaining pregnancy. It creates conditions for the fertilization of the egg, its implantation (introduction into the wall of the uterus) and the subsequent development of the fetus. If fertilization does not occur, then such a corpus luteum releases gestagens into the blood before the start of the next menstrual cycle and is usually called the menstrual corpus luteum, which functions until the start of the next menstrual cycle. In the case of fertilization of the egg, the corpus luteum of pregnancy is formed, which performs an endocrine function throughout the entire period of pregnancy. The most significant role of the corpus luteum is until 12-16 weeks of pregnancy, then the placenta is formed and the main role in the production of this hormone passes to this provisional organ. After the cessation of endocrine function, the corpus luteum undergoes involution (reverse development) and a scar remains in its place - a whitish body.

Estrogens are produced by maturing follicles. They ensure the development of the genital organs and the formation of secondary sexual characteristics according to the female type.