What is the name of the female organ. Female vagina anatomy

The vagina is a muscular tube covered from the inside by a mucous membrane, which is open in front and covers the cervix in the back. The front wall is located under the bladder, the back - above the rectum. The length of the vagina is 8-10 cm, in the middle part it reaches a width of 3 cm. At the same time, the vagina is very elastic and able to stretch. So, during childbirth, the width of this organ is able to increase to 10-12 cm, ensuring the exit of the fetus. Recent studies have shown that the vagina is able to "adapt" to the size of the penis of a regular partner. Therefore, it doesn’t matter how long or wide the man’s penis is, in any case, the vagina will tightly “grab” it, providing friction, which gives pleasure to both partners.

Inside, the vagina is covered with a mucous membrane secreting an oily whitish lubricant that is produced by the cervix during ovulation and the Bartholin gland during intercourse. The acidic environment inside this organ is a good protection against pathogenic microbes, although in some cases it can contribute to the occurrence of fungal diseases.

On the way from the vagina to the uterus, there is a dense muscle roller 3-4 cm in diameter with a tiny hole in the middle. This is the cervix. Menstrual blood pours out through a small hole in it. The same hole allows the penetration of sperm, which move in the direction of the fallopian tubes. In a nulliparous woman, the cervix has a round shape, after giving birth the cervix becomes wider, denser and transversely elongated. Like other "stages" of the birth canal, the cervix is \u200b\u200bvery elastic, and when the baby is born, it opens up several centimeters.

The uterus (or rather, the body of the uterus) is a pear-shaped muscular organ with a length of about 8 and a width of about 5 cm. Usually, the body of the uterus is tilted slightly forward and is located in the small pelvis behind the bladder. Inside the body there is a triangular cavity lined with endometrium - the mucous membrane with a network of blood vessels and glands, thickening during ovulation. Thus, the uterus prepares to accept a fertilized egg. If conception does not occur, the mucous membrane is rejected and menstruation occurs.

The fallopian tubes (fallopian tubes) are paired filiform organs that extend from the upper part of the uterus and lead to the ovaries, as if hugging them with their fringed ends. The length of the fallopian tubes is approximately 10-12 cm, and the inner diameter is very small, not thicker than the hair. The muscular tissue of the walls is dense and elastic, from the inside they are covered by the mucous membrane lined with cilia of the ciliated epithelium.

In the woman’s body, the fallopian tubes perform a very important function, it is in them that the egg is fertilized — its fusion with the sperm. The fallopian tubes are also the channel through which the egg enters the uterus. Cilia of the epithelium and fluid flow help the fertilized egg, slowly (3 cm per day), move towards the uterus. Once in the uterus, the egg attaches to the wall of its inner surface and grows and develops in the uterus for about 40 weeks.

Any obstruction or narrowing of the fallopian tubes can lead to the development of an ectopic pregnancy, which has to be interrupted, since the growing fetus can rupture the fallopian tube, which is a mortal danger for a woman.

The fallopian tubes together with the ovaries form the uterine appendages.

The ovaries are also paired organs that are located in the pelvis on either side of the uterus. Each of them is connected to the uterus by two ligaments, one of which attaches directly to the uterus, the other connects the ovary to the fallopian tube. The ovaries themselves are about 3 cm long and weigh about 5-8 g. Already from the name it is clear that the main function of these organs is to produce eggs. In addition, the ovaries produce sex hormones - estrogen and progesterone. These substances are unusually biologically active and are responsible for the formation of secondary sexual characteristics, physique, voice, body hair, regulate the functioning of the genitals and provide menstruation mechanisms and the normal course of pregnancy.

Unlike the male testes, which can produce sperm from puberty until death, the life of the ovaries is limited - egg production stops with menopause. Data on the number of germ cells (oocytes) in the ovaries vary. Most scientists agree that the newborn girl has about half a million, by the time of puberty there are about 30 thousand, but only 500-600 germ cells will turn into mature eggs and leave the ovaries. And only a few will be fertilized and give rise to a new life.

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The mechanisms of energy transformation in biostructures are associated with conformational transformations of special macromolecular complexes, such as the reaction centers of photosynthesis, H - ATPase of chloroplasts and mitochondria, and bacteriorhodopsin. Of particular interest are the general characteristics of the efficiency of energy conversion in such macromolecular machines. The thermodynamics of biological processes is called upon to answer these questions.

Female genitals are divided into external and internal.

The external genitalia.

The external genitalia in women include: the pubis, the labia minora and the labia minora, the bartholin glands, the clitoris, the vestibule of the vagina and the hymen, which is the boundary between the external and internal genital organs.

LOBOK - a triangular eminence, covered with hair, located above the bosom. The boundaries are: on top - the transverse skin sulcus; on the sides - inguinal folds.

In women, the upper border of the pubic scalp has the appearance of a horizontal line.

LARGE LIP-LIPS - two skin folds bordering the lateral fissure from the sides; frontally pass into the pubic skin, merge posteriorly into the posterior commissure. The skin on the outer surface of the labia majora is covered with hair, contains sweat and sebaceous glands, and blood vessels lie under it in the subcutaneous fat. , nerves and fibrous fibers, and in the posterior third - large glands of the vestibule (Bartholin glands) - rounded alveolar-tubular,

the size of a bean gland. Their excretory ducts open in the groove between the labia minora and the hymen, and their secret is secreted by sexual arousal.

The space between the posterior commissure and the anal opening is called the inter-

in the anatomical sense, the perineum is a muscle-fascial plate covered on the outside with skin. Its height is on average 3-4 cm.

LABORAL LIP LIPS - the second pair of longitudinal skin folds. They are located inward from the labia majora and are usually covered last. In front, the labia minora are bifurcated into two legs on each side, which merge to form the foreskin of the clitoris and frenum of the clitoris. large. Thanks to

the labia minora are the organs of the sexual sense.

CLITORIS. Outwardly, it is visible as a small tubercle in the anterior corner of the genital gap between the merged legs of the labia minora. The clitoris distinguishes the head, the body, which consists of the cavernous bodies and the legs, which are attached to the periosteum of the pubic and sciatic bones. Abundant blood supply and innervation make it the main organ of sexual sensation women.

Vaginal vestibule - the space bounded in front by the clitoris, behind by the posterior commissure of the labia, from the sides - the inner surface of the labia minora, from above - the hymen. This opens the external opening of the urethra and excretory ducts of the bartholin glands.

VIRGULAR BABY - a connective tissue membrane that closes the vagina's entrance to the vagina. In its connective tissue base there are muscular elements, blood vessels and nerves. There should be a hole in the hymen. It can be of any shape. After defloration, hymenal papillae remain after the hymen, after childbirth - myrrh-shaped papillae.

Internal genital organs.

These include: the vagina, uterus, fallopian tubes, and ovaries.

VAGINA - a well-extensible, muscular-elastic tube that runs in front and below the back and up. It starts from the hymen and ends at the place of attachment to the cervix. Medium size: 7-8 cm long (1.5-2 cm back wall) . longer), width 2-3 cm. Due to the fact that the front and back walls of the vagina are in contact, it is in the cross section in the shape of the letter N. Around the vaginal part of the cervix, which protrudes into the vagina, the walls of the vagina form a vaulted formation. front, back (deepest) and b kovye svody.Stenka vagina consist of three layers: mucous, muscular and surrounding tissue in which vessels and tested nervy.Myshechny layer consists of two layers: the outer and inner longitudinal tsirkulyarnogo.Slizistaya covered by stratified squamous epithelium comprising glycogen. The process of glycogen formation is associated with the follicular hormone of the ovary. The vagina is very well extensible due to the presence of two longitudinal ridges on the front and back walls, consisting of many transverse folds. There are no glands in the vaginal mucosa. The vagina secret is formed by soaking the fluid from the vessels. It has an acidic environment due to the formation of glycogen under the influence of enzymes and waste products of lactobacilli (Dederlein sticks) of lactic acid. Lactic acid contributes to the death of pathogenic micro -organisms.

There are four degrees of purity of the vaginal contents.

1 degree: only lactobacilli and epithelial cells in the contents, acid reaction.

2 degree: Dederlein rods smaller, single white blood cells, bacteria, many epithelial cells, acidic reaction.

3 degree: Lactobacilli are few, other types of bacteria predominate, many white blood cells, the reaction is slightly alkaline.

4 degree: there are no lactobacilli, there are a lot of bacteria and white blood cells, the reaction is alkaline.

1.2 degrees - a variant of the norm.

3.4 degrees indicate the presence of a pathological process.

UTERUS - a smooth muscle hollow organ that has the shape of a pear, flattened in the anteroposterior direction.

Departments of the uterus: body, isthmus, cervix.

The domed part of the body above the pipe attachment lines is called the bottom of the uterus.

Isthmus  - a part of the uterus 1 cm long, located between the body and the cervix. It is allocated in a separate section, since the structure of the mucous membrane is similar to the uterine body, and the wall structure is similar to the cervix. The upper border of the isthmus is the place of tight attachment of the peritoneum to the front wall of the uterus. the boundary is the level of the internal pharynx of the cervical canal.

Neck - the lower part of the uterus, protruding into the vagina. It distinguishes two parts: the vaginal-vaginal and supravaginal. The cervix can be either cylindrical or conical (childhood, infantilism). A narrow channel with a fusiform shape is located inside the cervix, limited internal and external pharynx. The external pharynx opens in the center of the vaginal part of the neck. It has the shape of a gap in the parturition and rounded in the case of nulliparous women.

The length of the entire uterus is 8 cm. (2/3 of the length falls on the body, 1/3 on the neck), width 4-4.5 cm, wall thickness 1-2 cm. Weight 50-100 g. The uterine cavity has the shape of a triangle.

The uterine wall consists of 3 layers: mucous, muscle, serous. Mucous membrane of the uterus (endometrium)  is covered with a single-layer cylindrical ciliated epithelium containing tubular glands. The uterine mucosa is divided into two layers: superficial (functional), which bends during menstruation, deep (basal), which remains in place.

Muscle layer   (myometrium)it is richly equipped with vessels, consists of three powerful layers: the outer longitudinal; the middle circular; the internal longitudinal.

Uterine serosa (perimetry)  Is the peritoneum, covering the body and partially the cervix. From the bladder, the peritoneum passes to the front surface of the uterus, forming a vesicoureteral cavity between the two organs. From the bottom of the uterus, the peritoneum descends along its back surface, lining the supravaginal part of the cervix and the posterior vaginal vault , and then goes to the front surface of the rectum, thus forming a deep pocket - rectal-uterine depression (Douglas space).

The uterus is located in the center of the small pelvis, is inclined anteriorly (anteversio uteri), its bottom is directed to the symphysis, the cervix is \u200b\u200bposterior, the external pharynx of the cervix is \u200b\u200badjacent to the wall of the posterior vaginal fornix. There is an obtuse angle between the body and the cervix, open anteriorly (anteflexio uteri).

UTERINE TUBES begin from the upper corners of the uterus, go along the upper edge of the wide ligament towards the side walls of the pelvis, ending with a funnel. Their length is 10-12 cm. Three sections are distinguished in the tube: 1) interstitial  - the narrowest part, passing in the thickness of the uterus; 2) isthmus (isthmus); 3) ampullar  - the expanded part of the tube, ending with a funnel with fimbriae. In this section of the tube, fertilization occurs - the fusion of the egg and sperm.

The tube wall consists of three layers: mucous, muscle, serous.

The mucous membrane is covered with a single-layer cylindrical ciliated epithelium, has longitudinal folding.

The muscle layer consists of three layers: the outer - longitudinal; the middle - circular; the inner - longitudinal.

The peritoneum covers the tube from above and from the sides. Fiber with vessels and nerves adheres to the lower part of the tube.

Prolonged contractions of the musculature of the tube, flickering of the cilia of the epithelium directed towards the uterus and the longitudinal folding of the mucosa contribute to the progression of the fertilized egg through the tube towards the uterus. The egg glides along the fold like a gutter towards the uterus.

OVARIES - a pair of female gonads of almond-shaped, measuring 3.5-4 x 2-2.5 x 1-1.5 cm, weighing 6-8g.

The ovary is inserted with one edge into the posterior leaf of the broad ligament (the ovarian collar), the entire remaining part of it is not covered by the peritoneum. The ovary is held in a freely suspended state by the wide uterine ligament, its own ligament of the ovary, and funnel-pelvic ligament.

In the ovary, the integument epithelium, the tunica albuginea, the cortical layer with follicles at different stages of development, and the cerebral layer, consisting of connective tissue stroma, in which the vessels and nerves pass, are distinguished.

In the ovaries, sex hormones are produced, the eggs mature.

The ligamentous apparatus of the genitals.

In the normal position, the uterus with appendages is held by the ligamentous apparatus (suspensory and fixative apparatuses) and the pelvic floor muscles (supporting or supporting apparatus).

The hanging device includes:

1. Round uterine ligaments - two cords with a length of 10-12 cm. Depart from the uterine corners, and passing under the wide uterine ligament and through the inguinal canals, fan-shaped branches, attaching to the fiber of the pubis and large labia.

2. Wide ligaments of the uterus - a duplicate of the peritoneum. They go from the edges of the uterus to the side walls of the pelvis.

3. Sacro-uterine ligaments - depart from the posterior surface of the uterus in the isthmus, go

posteriorly, covering the rectum on both sides. Attached to the anterior surface of the sacrum.

4. Own ligaments of the ovaries go from the bottom of the uterus (posteriorly and below the place of discharge of the tubes) to the ovaries.

5. Voronkotazovye ligaments - the outermost part of the wide uterine ligament, passing into the peritoneum of the side wall of the pelvis.

The round ligaments keep the uterus in anteversio state, the wide ligaments tense during the movement of the uterus and thereby contribute to the retention of the uterus in the physiological position, the ovary’s own ligaments and the funnel-pelvic ligaments help to keep the uterus in the middle position, the sacro-uterine ligaments attract the uterus posteriorly.

The fixing device of the uterus consists of connective tissue cords with a small number of muscle cells that go from the lower part of the uterus: a) anteriorly to the bladder and further to the symphysis; b) to the side walls of the pelvis - the main ligaments; c) posteriorly, making up the connective tissue skeleton of the sacro-uterine ligaments.

The supporting apparatus is constituted by the muscles and fascia of the pelvic floor, which prevent the genitals and viscera from dropping down.

Blood supply to the genitals.

The external genital organs are supplied with blood through the shameless artery (a branch of the internal iliac artery).

Blood supply to the internal genital organs is provided by the uterine and ovarian arteries.

The uterine artery is paired, departs from the internal iliac artery, goes to the uterus along the peritoneal tissue, approaches the lateral surface of the uterus at the level of the internal pharynx, gives the cervical-vaginal branch supplying the cervix and upper vagina. The main trunk rises along the edge of the uterus, giving numerous branches that feed the uterine wall, and reaches the bottom of the uterus, where it gives a twig that goes to the tube.

The ovarian artery is also paired, departs from the abdominal aorta, goes down along with the urine, passes through the funnel-pelvic ligament, giving branches to the ovary and tube.The end sections of the uterine and ovarian arteries anastomose to each other in the upper section of the wide uterine ligament.

Arteries are accompanied by the same veins.

Genital innervation.

The sympathetic and parasympathetic nervous systems (uterine-vaginal and ovarian plexuses) take part in the innervation of the genital organs.

The external genitalia and the pelvic floor are innervated by the shameful nerve.

Physiology of the female genital organs.

It is known that reproduction, or reproduction, is one of the most important functions.

the female body. The reproductive function of women is carried out primarily due to the activity of the ovaries and uterus, since the egg matures in the ovaries, and changes occur in the uterus under the influence of hormones secreted by the ovaries in preparation for the perception of a fertilized fetal egg. The reproductive (reproductive) period continues from 17-18 to 45-50 years.

The childbearing period is preceded by the following stages of a woman's life: intrauterine; newborns (up to 1 year); childhood (up to 8-10 years); prepubertal and puberty (up to 17-18 years). The reproductive period goes into menopause, which distinguishes between premenopause, menopause (last menstruation) and postmenopause.

The menstrual cycle is one of the manifestations of complex biological processes in a woman's body. The menstrual cycle is characterized by cyclical changes in all parts of the reproductive system, the external manifestation of which is menstruation.

Each normal menstrual cycle is the preparation of the woman’s body for pregnancy. Conception and pregnancy usually occur in the middle of the menstrual cycle after ovulation (rupture of the mature follicle) and the ovum ready to fertilize the egg from the ovary. If fertilization does not occur during this period, the unfertilized egg dies, and the prepared for its perception, the uterine mucosa is rejected and menstrual bleeding begins. Thus, the appearance of menstruation indicates the end of complex iklicheskih changes in a woman's body, aimed at preparing for a possible pregnancy.

The first day of menstruation is conventionally taken as the first day of the menstrual cycle, and the duration of the cycle is determined from the beginning of one to the beginning of another (subsequent) menstruation. The normal duration of the menstrual cycle ranges from 21 to 35 days and most women average 28 days. blood loss on menstrual days 50-100 ml. The duration of normal menstruation from 2 to 7 days.

The first menstruation (menarhe) is observed at the age of 10-12 years, but within 1-1.5 years after this, menstruation can be irregular, then a regular menstrual cycle is established.

Regulation of menstrual function is carried out in a complex neurohumoral way with the participation of five links (levels): 1) the cerebral cortex; 2) the hypothalamus; 3) the pituitary gland; 4) the ovaries; 5) peripheral organs called target organs (fallopian tubes, uterus and vagina). Target organs, due to the presence of special hormonal receptors, most clearly respond to the action of sex hormones produced in the ovaries during the menstrual cycle.

The cyclic functional changes occurring in a woman’s body are conditionally combined into several groups. These are changes in the hypothalamus-pituitary gland, ovaries (ovarian cycle), uterus, and primarily in its mucous membrane (uterine cycle) .In addition, cyclic shifts occur throughout the body of a woman, known as the menstrual wave. They are expressed in periodic changes in the central nervous system, metabolic processes, the function of the CCC, thermoregulation, etc.

The cerebral cortex carries out a regulatory and corrective effect on the processes associated with the development of menstrual function. Through the cerebral cortex, the external environment affects the underlying parts of the nervous system involved in the regulation of the menstrual cycle.

The hypothalamus is a part of the diencephalon and is connected to various parts of the brain via a series of nerve conduits (axons), which ensures central regulation of its activity. In addition, the hypothalamus contains receptors for all peripheral hormones, including ovarian (estrogen and progesterone). Thus, in the hypothalamus, complex interactions are carried out between pulses entering the body from the environment through the central nervous system, on the one hand, and

the effects of hormones of the peripheral glands of internal secretion - on the other.

Under the control of the hypothalamus is the activity of the brain appendage - the pituitary gland, in the anterior lobe of which gonadotropic hormones are released that affect the function of the ovaries.

The controlling effect of the hypothalamus on the anterior pituitary is carried out through the secretion of neurohormones.

Neurohormones that stimulate the release of tropic pituitary hormones are called releasing factors or liberins. Along with this, there are also neurohormones that inhibit the release of tropic neurohormones called statins.

In the anterior pituitary gland, follicle-stimulating (FSH) and luteinizing (LT) gonadotropins, as well as prolactin, are secreted.

FSH stimulates the development and maturation of a follicle in one of the ovaries. Under the combined action of FSH and LH, a mature follicle ruptures, or ovulation occurs. After ovulation under the predominant influence of LH, a yellow body forms from the follicle (connective tissue membrane and granulating cells lining its inner surface). Prolactin promotes corpus luteum production of progesterone.

In the ovaries, during the menstrual cycle, follicles grow and the ovum ripens, which, as a result, becomes ready for fertilization. At the same time, sex hormones are produced in the ovaries, which provide changes in the mucous membrane of the uterus, which can absorb a fertilized egg.

Sex hormones synthesized by the ovaries affect target tissues and organs by interacting with the corresponding receptors. Target tissues and organs include the genitals, primarily the uterus, mammary glands, spongy bone, brain, endothelium and smooth muscle cells blood vessels, myocardium, skin and its appendages (hair follicles and sebaceous glands), etc.

Estrogenic hormones contribute to the formation of the genitals, the development of secondary sexual characteristics during puberty. Androgens affect the appearance of hair growth on the pubis and armpits. Progesterone controls the secretory phase of the menstrual cycle, prepares the endometrium for implantation. Sex hormones play an important role in the development of pregnancy and childbirth.

Cyclical changes in the ovaries include three main processes:

1) follicular growth and the formation of a dominant follicle (follicular phase);

2) ovulation;

3) the formation, development and regression of the corpus luteum (luteal phase).

At the birth of a girl, the ovary contains 2 million follicles, 99% of which undergo atresia throughout life. The atresia process refers to the reverse development of follicles at one of the stages of its development. By the time of the menarche, the ovary contains about 200-400 thousand follicles, of which mature to the ovulation stage 300-400.

The following main stages of follicular development are distinguished: primordial follicle, preantral follicle, antral follicle, preovulatory (dominant) follicle. The dominant follicle is the largest (by the time of ovulation 21 mm).

Ovulation is the rupture of the dominant follicle and the exit of the egg. The thinning and rupture of the follicle wall occurs mainly under the influence of the collagenase enzyme.

After the egg enters the follicle cavity, the formed capillaries quickly grow. Granulosa cells undergo luteinization: they increase the volume of the cytoplasm and lipid inclusions form. LH, interacting with the protein receptors of granulosa cells, stimulates the process of their luteinization. This process leads to the formation of a corpus luteum.

The corpus luteum is a transient endocrine gland that functions for 14 days regardless of the length of the menstrual cycle. In the absence of pregnancy, the corpus luteum regresses.

Cyclical secretion of hormones in the ovary determines changes in the mucous membrane of the uterus. The endometrium consists of two layers: the basal layer, which is not torn away during menstruation and the functional one, which undergoes cyclic changes during the menstrual cycle and is rejected during the period of menstruation.

The following phases of endometrial change during the cycle are distinguished:

1) the proliferation phase; 3) menstruation;

2) phase of secretion; 4) regeneration phase

Proliferation phase.As the secretion of estradiol increases by the growing ovarian follicles, the endometrium undergoes proliferative changes. Active propagation of the cells of the basal layer occurs. A new surface loose layer with elongated tubular glands forms. This layer quickly thickens by 4-5 times. Tubular glands lined with cylindrical epithelium.

Secretion phase.In the luteal phase of the ovarian cycle, under the influence of progesterone, the tortuosity of the glands increases, and their lumen gradually expands. The stromal cells, increasing in volume, approach each other. The secretion of the glands increases. They acquire a sawtooth shape. There is an increased vascularization of the stroma.

Menstruation.This is the rejection of the functional layer of the endometrium. The endocrine basis for the onset of menstruation is a pronounced decrease in progesterone and estradiol levels due to regression of the corpus luteum.

The regeneration phase.Endometrial regeneration is observed from the very beginning of menstruation. By the end of the 24th hour of menstruation, 2/3 of the functional layer of the endometrium is rejected. The basal layer contains stromal epithelial cells, which are the basis for endometrial regeneration, which usually ends by the 5th day of the cycle. Angiogenesis ends in parallel with the restoration of the integrity of torn arterioles, veins and capillaries.

In the regulation of menstrual function, the implementation of the principle of the so-called feedback between the hypothalamus, the anterior pituitary and the ovaries is of great importance. It is customary to consider two types of feedback: negative and positive.

With a negative type of feedback, the production of central neurohormones (releasing factors) and gonadotropins of the adenohypophysis are suppressed by ovarian hormones produced in large quantities. With a positive type of feedback, the production of releasing factors in the hypothalamus and gonadotropins in the pituitary are stimulated by a low level of ovarian hormones in the blood. The implementation of the principle of non-negative and positive feedback is the basis of self-regulation of the function of the hypothalamus-pituitary-ovary system.

Female pelvis and pelvic floor.

The bony pelvis is of great importance in obstetrics. It is a receptacle for the internal genital organs, rectum, bladder and surrounding tissues, and during childbirth forms the birth canal through which the fetus moves.

The pelvis consists of four bones:  two pelvic (nameless), sacrum and tailbone.

The pelvic bone consists of three bones: the iliac, pubic and sciatic, interconnected in the acetabulum.

There are two parts of the pelvis:  a large basin and a small basin. The border between them runs in front along the upper edge of the pubic joint, laterally along an anonymous line, posteriorly along the sacral promontory.

Big basin  limited from the sides by the wings of the ilium, from behind by the last lumbar vertebrae. In front, it has no bone wall. By the size of the large pelvis, which is easy enough to measure, they judge the shape and size of the small pelvis.

Small basin  represents the bone part of the birth canal. The shape and size of the pelvis are of great importance during the birth certificate. With sharp degrees of narrowing of the pelvis and its deformations, childbirth through the natural birth canal becomes impossible, and the woman is delivered by cesarean section.

The posterior wall of the pelvis consists of the sacrum and coccyx, the lateral ones are formed by the ischial bones, the anterior one is the pubic bones and the symphysis. The posterior wall of the pelvis is three times longer than the anterior.

In the small pelvis, there are the following departments: entrance, cavity and exit.  In the pelvic cavity, a wide and narrow part is distinguished. In accordance with this, four planes of the small pelvis are considered: 1) the plane of the entrance to the small pelvis; 2) the plane of the wide part of the small pelvis; 3) the plane of the narrow part of the small pelvis; 4) the plane of the exit of the pelvis.

Basin Entrance Plane   It has the following boundaries: in front - the upper edge of the symphysis and pubic bones, on the sides - nameless lines, behind - the sacral cape. The entrance plane has a kidney-shaped shape. The following dimensions are distinguished in the entrance plane: a straight line, which is the true conjugate of the small pelvis (11 cm), transverse (13 cm) and two oblique (12 cm).

The plane of the wide part of the pelvic cavity   bounded in front by the middle of the inner surface of the symphysis, on the sides by the middle of the acetabulum, with the junction of the II and III sacral vertebrae. In the wide part, there are two sizes of the straight (12.5 cm) and transverse (12.5 cm)

The plane of the narrow part of the pelvic cavity bounded in front by the lower edge of the symphysis, with the sides by the remains of the ischial bones, behind by the sacrococcygeal connection. There are also two sizes: straight (11 cm) and transverse (10.5 cm).

Pelvic exit plane   It has the following boundaries: in front - the lower edge of the symphysis, on the sides - sciatic tubercles, behind - the coccyx. The exit plane of the pelvis consists of two triangular planes, the common base of which is the line connecting the ischial tubercles. The direct size of the exit of the pelvis - from the top of the coccyx to the lower edge of the symphysis, due to the mobility of the coccyx during the passage of the fetus through the small pelvis increases by 1.5 - 2 cm (9.5-11.5 cm). The transverse size is 11 cm.

The line connecting the midpoints of the direct dimensions of all the planes of the pelvis is called pelvic axis,   since it is along this line during childbirth that the fetus passes through the birth canal. The wire axis is curved according to the concavity of the sacrum.

The intersection of the entrance plane to the pelvis with the horizon plane forms pelvic angle  equal to 50-55 ’.

Differences in the structure of the female and male pelvis begin to appear during puberty and become pronounced in adulthood. The bones of the female pelvis are thinner, smoother, and less massive than the bones of the male pelvis. The plane of entry into the pelvis in women has a transverse oval shape, while in men it has the shape of a card heart (due to the strong protrusion of the cape).

Anatomically, the female pelvis is lower, wider and larger in volume. Pubic symphysis in the female pelvis is shorter than the male. The sacrum of women is wider, the sacral cavity is moderately concave. The pelvic cavity in women outlines close to the cylinder, and in men it is funnel-shaped narrowing downward. The pubic angle is wider (90-100 ’) than that of men (70-75’), the tailbone is anteriorly smaller than in the male pelvis. The sciatic bones in the female pelvis are parallel to each other, and in the male, they converge.

All of these features are very important in the process of labor.

Pelvic floor muscles.

The pelvic exit is closed from below by a powerful muscular-fascial layer called pelvic floor.

Two diaphragms are involved in the formation of the bottom of the pelvis - the pelvic and urogenital.

Pelvic diaphragm  it occupies the back of the perineum and has the form of a triangle, the apex of which is directed to the coccyx, and the corners to the sciatic tubercles.

The surface layer of the muscles of the pelvic diaphragm It is represented by an unpaired muscle - the external sphincter of the anus (m.sphincter ani externus). The deep bundles of this muscle begin from the tip of the coccyx, wrap around the anus and end in the tendon center of the perineum.

To the deep muscles of the pelvic diaphragm  two muscles belong: the muscle lifting the anus (m.levator ani) and the coccygeal muscle (m. coccygeus).

The muscle that lifts the anus is paired, triangular in shape, with a similar muscle on the other side, forms a funnel, with the wide part facing up and attached to the inner surface of the walls of the pelvis. The lower parts of both muscles, tapering, cover the rectum in the form of a loop. This muscle consists of the pubic-coccygeal (m. Pubococcygeus) and the iliac-coccygeal muscles (m.iliococcygeus).

The coccygeal muscle in the form of a triangular plate is located on the inner surface of the sacro-spinous ligament. With a narrow top, it starts from the sciatic spine, with a wide base attached to the lateral edges of the lower sacral and coccygeal vertebrae.

Genitourinary diaphragm  –Fascial – muscular plate located in front of the bottom of the pelvic floor between the lower branches of the pubic and sciatic bones.

The muscles of the urogenital diaphragm are divided into superficial and deep.

To surfaceinclude the superficial transverse muscle of the perineum, the sciatic-cavernous muscle and the bulbous-spongy.

The superficial transverse muscle of the perineum (m.transversus perinei superficialis) is paired, unstable, sometimes it can be absent on one or both sides. This muscle is a thin muscle plate located at the posterior edge of the urogenital diaphragm and running across the perineum. With the lateral end, it is attached to the sciatic bone, the medial part crosses along the midline with the same muscle of the opposite side, partially woven into the bulbous-spongy muscle, partially into the external muscle compressing the anus.

The sciatic-cavernous muscle (m.ischiocavernosus) is a pair, looking like a narrow muscle strip. It begins with a narrow tendon from the inner surface of the sciatic tubercle, bypasses the clitoris leg and is woven into its protein membrane.

The bulbous-spongy muscle (m. Bulbospongiosus) is a pair, surrounds the entrance to the vagina, has the shape of an elongated oval. This muscle starts from the tendon center of the perineum and the external sphincter of the anus and attaches to the dorsal surface of the clitoris, interwoven into its protein membrane.

To the deep the muscles of the urogenital diaphragm include the deep transverse muscle of the perineum and the sphincter of the urethra.

The deep transverse muscle of the perineum (m. Transversus perinei profundus) is a paired, narrow muscle starting from the sciatic tubercles. She goes to the midline, where she connects with the same muscle of the opposite side, participating in the formation of the tendon center of the perineum.

The urethra sphincter (m.sphincter urethrae) is a paired muscle, lies anterior to the previous one. Peripherally located bundles of this muscle are directed to the branches of the pubic bones and to the fascia of the urogenital diaphragm. Bunches of this muscle surround the urethra. This muscle connects to the vagina.

Sexual intercourse is a mechanism for the complex interaction of male and female genital organs. The anatomy of intimacy provides the connection of the egg and sperm, resulting in conception. For a better understanding, we will analyze what happens during sex.

Anatomical features of organs

Before you begin to consider the anatomy of sexual intercourse, you need to remember how the male and female reproductive systems work. It is also necessary to understand the function of each component of the reproductive system. First, consider the genitals of women.

• The ovaries.

These are paired glands located in the pelvic cavity. Their function is to secrete female sex hormones. Also, egg maturation occurs in them.

• Fallopian, or uterine, tubes.

The fallopian tubes are a paired tubular structure. With their help, the uterine cavity is connected to the abdominal.

• Uterus.

The hollow organ is a reservoir for bearing the fetus. The neck, isthmus and body are distinguished in the structure of the organ.
  Female reproductive system.

• Vagina.

This is a muscular organ, which is a tube that connects to the uterus. When excited, the walls are abundantly smeared with the secretion of the vaginal and bartholin glands, as well as with the plasma penetrating from the blood vessels. The muscle layer of the organ allows the vagina to stretch to the desired size. This fact of anatomy is important during intercourse and during childbirth.

• Large and small labia.

They are located on the edges of the genital fissure, so they cover and protect the vagina. These structures are rich in sensitive nerve endings. The labia minora are well supplied with blood, and when sexually aroused, they are filled with blood and slightly increase in size.

• Bartholin glands.

These are glands of external secretion, which are located in the thickness of the labia majora. Their excretory ducts are located in the junction of the labia minora and labia majora, and the secret is needed to moisturize the vestibule.

• Clitoris.

This is a small tubercle located in the anterior commissure of the labia minora, its main function is to ensure orgasm. During excitation, an increase in clitoris in size and swelling is observed.

The organs of the reproductive system in men are also divided into external and internal. Consider the structure of the male genital organs. Their anatomy is presented below:

• Testicles.

These are paired glands that are located in the scrotum. The function is to produce testosterone and sperm.

• Seminal vesicles.

Tubular formations with many hollow chambers. They contain nutrients for sperm to ensure their functioning.

• Seminal tubules.

Designed for blood supply to the testicles and the removal of seed from them. Here, sperm cells form from the primary germ cells.

   Male reproductive system.

• The vas deferens are structures designed to eject sperm.
• Penis.

This is the main organ during sexual intercourse. It consists of two cavernous bodies and one spongy. Anatomically isolate the head and body of the penis. It is important to note that the entire surface of the penis is saturated with sensitive receptors. Therefore, this is the main erogenous zone of men.

• Prostate.

This is one of the main glands of the male body. The prostate is involved in the regulation of sexual abilities, is responsible for the quality of sperm.

What happens during coitus

For sexual intercourse, it is necessary that both the man and the woman are in a state of excitement. In a man, this is manifested by the presence of an erect penis, and in a woman by an increase in vaginal secretion. Excitation is promoted not only by physical factors, such as stimulation of erogenous zones. In the formation of preparation for sexual intercourse, psychological and sensory factors take part.

In response to the stimulation of certain parts of the brain and spinal cord in men, an expansion of the blood vessels of the penis is observed. As a result, blood flow increases, filling of the corpora cavernosa, and the genital organ grows in size and hardens. It is this mechanism that determines the formation of an erection, which makes the penetration of the penis into the vagina possible.

In women, during arousal, blood flow to the genitals increases, and the secretion of glands increases. Through the walls of numerous blood vessels surrounding the vagina, the liquid part of the blood plasma seeps into its lumen. This anatomy provides hydration to the vaginal mucosa, which facilitates intercourse. It is worth noting that normally the size of the vagina is about 8 cm, but due to the elasticity at the time of intercourse, the organ can expand, change shape, adjusting to the size of the penis.

   For sexual intercourse it is necessary that both the man and the woman are in a state of excitement.

The process of introducing the penis into the vagina is an even greater stimulator of sexual activity. Then the man begins to make frictions. These are reciprocating movements performed by the pelvis, due to which mutual sexual stimulation occurs. The anatomy of women is designed so that stimulation of the cervix, vagina and clitoris brings maximum satisfaction. In men, the peak of sexual pleasure is observed with direct irritation of the glans penis.

Sexual intercourse ends with an orgasm. At the same time, in men, contractions of intimate muscles lead to the release of sperm. Semen is released in several portions. The female reproductive system is such that, at the time of orgasm, muscle contractions prevent the flow of seminal fluid and promote its advancement to the cervix. Subsequently, sperm enters the uterine cavity, then from the area of \u200b\u200bits bottom penetrates into the fallopian tubes.

If sexual intercourse occurs during ovulation, then the probability of fertilization of the egg is high. Normally, conception occurs in the fallopian tube, and only then the fertilized egg descends into the uterus, where it attaches.

The physiology of sexual intercourse is a complex process of interaction between all organs of the reproductive system, as well as a cascade of biochemical processes. To understand the mechanism of sexual intercourse, it is necessary to clearly understand how the reproductive system of men and women is arranged. This will help you better understand your feelings and find the key to achieving maximum pleasure for your partner.

Female genitals are divided into external (vulva) and internal. The internal genital organs provide conception, the external ones participate in sexual intercourse and are responsible for sexual sensations.

Internal genitalia include the vagina, uterus, fallopian tubes, and ovaries. To the external - pubis, labia minora, labia minora, clitoris, vestibule of the vagina, large glands of the vestibule (bartholin glands). The boundary between the external and internal genital organs is the hymen, and after the onset of sexual activity - its remains.

External genitalia

Pubis  (venereum tubercle, lunar mound) - the lowest part of the anterior abdominal wall of a woman, slightly rising due to the well-developed subcutaneous fat layer. The pubic area has a pronounced hairline, which is usually darker than on the head, and in appearance it is a triangle with a sharply defined upper horizontal border and a vertex pointing down. The labia (shameful lips) are folds of skin located on both sides of the genital gap and the vestibule of the vagina. Distinguish between large and small labia

Big labia -  skin folds in the thickness of which is rich in fat fiber. The skin of the labia majora has many sebaceous and sweat glands, and during puberty it is covered with hair from the outside. In the lower parts of the labia majora, the Bartholin glands are located. In the absence of sexual stimulation, the labia majora are usually closed in the midline, which creates mechanical protection for the urethra and entry into the vagina.

Labia minora  located between the large labia in the form of two thin delicate skin folds of pink color, limiting the vestibule of the vagina. They have a large number of sebaceous glands, blood vessels and nerve endings, which allows us to consider them the organ of sexual sensation. Small lips converge above the clitoris, forming a skin fold called the foreskin of the clitoris. During sexual arousal, the labia minora become saturated with blood and turn into elastic ridges that narrow the entrance to the vagina, which increases the intensity of sexual sensations with the introduction of the penis.

Clitoris  - Female external genitalia located at the upper ends of the labia minora. This is a unique organ whose only function is to concentrate and accumulate sexual sensations. The size and appearance of the clitoris have individual differences. Length - about 4-5 mm, but in some women it reaches 1 cm or more. With sexual arousal, the clitoris increases in size.

The vestibule of the vagina - slit-like space, limited laterally by the labia minora, front by the clitoris, posterior by the posterior adhesion of the labia. On top of the vestibule of the vagina is covered with hymen or its remnants. On the eve of the vagina, the external opening of the urethra, located between the clitoris and the entrance to the vagina, opens. The vestibule of the vagina is sensitive to touch and at the time of sexual arousal is poured with blood, forming an elastic elastic "cuff", which is moisturized by the secret of large and small glands (vaginal lubrication) and opens the entrance to the vagina.

Bartholin glands  (large glands of the vestibule) are located in the thickness of the labia majora at their base. The size of one gland is about 1.5-2 cm. Glands during sexual arousal and intercourse secrete a viscous grayish protein-rich fluid (vaginal fluid, lubricant).

Internal genitalia

Vagina (vagina)  - the internal sexual organ of a woman who is involved in the process of sexual intercourse, and in childbirth is part of the birth canal. The length of the vagina in women is, on average, 8 cm. But for some, it can be longer (up to 10-12 cm) or shorter (up to 6 cm). Inside the vagina is lined with a mucous membrane with a large number of folds, which allows it to stretch during childbirth.

Ovaries  - female gonads, from the moment of birth they contain more than a million immature eggs. The ovaries also form hormones estrogen and progesterone. Due to the constant cyclic change in the content of these hormones in the body, as well as the release of hormones by the pituitary gland, egg maturation and their subsequent exit from the ovaries occur. This process is repeated approximately every 28 days. The release of an egg is called ovulation. In the immediate vicinity of each ovary is the fallopian tube.

Fallopian tubes (fallopian tubes) -  two hollow tubes with holes going from the ovaries to the uterus and opening in its upper part. At the ends of the tubes near the ovaries there are villi. When the egg leaves the ovary, the villi, with their continuous movements, try to capture it and drive it into the tube so that it can continue on to the uterus.

Uterus  - a hollow organ shaped like a pear. It is located in the pelvic cavity. During pregnancy, the uterus increases as the fetus grows. The walls of the uterus are composed of layers of muscle. With the onset of labor and during labor, the uterine muscles contract, the cervix stretches and opens and the fetus is pushed into the birth canal.

Cervix represents its lower part with a passage connecting the uterine cavity and the vagina. During childbirth, the walls of the cervix become thinner, the pharynx of the cervix expands and takes the form of a round hole with a diameter of approximately 10 centimeters, due to which it becomes possible for the fetus to exit the uterus into the vagina.

Hymen  (hymen) - a thin fold of the mucous membrane in virgins located at the entrance to the vagina between the internal and external genital organs. Each girl has individual, only her inherent features of hymen. In the hymen there is one or more holes of various sizes and shapes through which blood is released during menstruation.

At the first sexual contact, the hymen ruptures (defloration), usually with the release of a small amount of blood, sometimes with a sensation of pain. At the age of over 22 years, the hymen is less elastic than at a young age, therefore, in young girls, defloration usually occurs easier and with less blood loss, cases of sexual intercourse and without rupture of the hymen are frequent. Ruptures of the hymen can be deep, with heavy bleeding, or superficial, with minor spotting. Sometimes with too elastic hymen, rupture does not occur, in this case defloration occurs without pain and spotting. After childbirth, the hymen is completely destroyed, only its individual rags remain.

The girl’s lack of blood during defloration should not cause jealousy or suspicion, since it is necessary to take into account the individual structural features of the female genital organs.

In order to reduce pain during defloration and increase the duration of sexual intercourse, lubricants containing drugs that reduce the pain sensitivity of the vaginal mucosa can be used.

Literally 10-15 years ago, the word "vagina" or "vagina" could cause extreme indignation and bewilderment. Most people who want to know the structure of their bodies, especially virgins, were simply afraid to raise this topic so as not to become “ignorant” in the eyes of others. Nevertheless, interest in the woman’s body, both from her and from the man’s side, has not lost its relevance. Many people ask and search for information, videos and photos of the vagina to "calculate the compatibility" of the genitals in order to avoid, for example, pain during intercourse. From this article you can learn more about female genital organs.

The vagina is an organ of the internal reproductive system, which is a fairly narrow muscle channel in the form of a tube with elastic walls that connects the vulva and uterus. This organ of the female body plays an important role in fertilization, as well as the birth of a child.

In general, the reproductive system of the fair half of humanity consists not only of the pelvic organs. It is also the mammary and endocrine glands, the operation of which is controlled by some parts of the brain. And they all take part in the fulfillment of the mission - the birth of the baby. The organs of the reproductive system are divided into external and internal, depending on their location in the body. And the vagina refers to the internal, which shows the photo.

How does this organ work?

Considering the structure of the vagina, it is worth noting that this is a hollow tube of muscles. It is located in the body, slightly bending to the top. Each young girl (including a virgin), as a rule, has corrugated walls. And her size is different for every woman. According to statistics, as well as research results, the average length of the tube can be from 8 to 12 cm. Regarding the width of the vagina, the average is 2-3 cm. Although during intercourse and childbirth, it can increase many times, reaching a diameter of 9 up to 12 cm.

Its walls consist of 3 layers. In general, their total thickness is about 4 mm. They are soft to the touch. Each wall is a layer that performs its function:

The inner layer, which is a mucous membrane consisting of many folds. Thanks to them, the vagina has the ability to increase in size.

The middle, smooth muscle layer. The muscle bundles (longitudinal and transverse), which are presented in this wall, are present both in the upper part of the vagina and in its lower part. Unlike the upper ones, the lower bundles are more durable. They are woven into the muscles that regulate the work of the perineum.

Outer layer (adventitious). This wall is represented by connective tissue, in which there are elements of elastic fibers and muscles. It performs a connective function, combining the vagina and organs that are not related to the reproductive system. So, for example, the rectum, located behind the vagina, as well as the bladder located in front of it, are connected precisely by the tissues of the outer layer.

As shown in the photo above, the female vagina has two walls (front, back). The ring that these walls form at the top, uniting, covers part of the uterus. They form a "arch", highlighting part of the vagina at the beginning of the cervix.

The lower ring, created by the front and back walls of the vagina, form a vestibule opening. It is here that the hymen is located. As you know, this is a film that virgins have. Its dimensions and structure are purely individual. But for every virgin, she is thin and quite elastic. This allows girls who have not entered into sexual intercourse to freely use tampons.

It is worth noting that contrary to prevailing public opinion, hymen (hymen) is not evidence confirming the chastity of the fair sex. And this film can be easily damaged during physical exercises that require strong muscle tension, as well as during masturbation. In addition, the true purpose from the physiological point of view of the hymen has not yet been established.

In order for the vaginal microflora to be healthy, it must always be moist. This function is provided by the inner walls.

They have glands that secrete special mucus. It is a discharge of a whitish color, which is characteristic of a characteristic smell. Mucus also has a slightly acid reaction, which prevents the development of pathogenic bacteria and other microorganisms. In addition, the secreted mucus provides a normal moistened vagina from the inside, it contributes to the painless implementation of sexual intercourse, which is often experienced by virgins.

However, it is worth knowing that the normal secretion of mucus does not bother with excessive manifestations. Therefore, if you began to notice abundant vaginal discharge, you should consult your gynecologist. If they are not a sign of ovulation, then these secretions can become a symptom of the inflammatory process.

About the functions performed by this body

You have already learned about the structure of the vagina. Now you can familiarize yourself with the functions that this female organ performs. There are 4 of them:

1. Sexual This is the main function that the vagina performs in the body of a woman, taking a direct part in the conception of the child. Sperm secreted by a man during unprotected intercourse, it gets into the vagina, getting the opportunity to penetrate the cervix. Thus, reaching the uterine tube, the sperm can fertilize the egg, which will give rise to a new life.
2. Generic.  Both walls of the vagina, connecting with the cervix, form a channel. It is called generic, because during childbirth, the fetus from the uterus passes through this channel. This is because during the course of pregnancy the woman’s body prepares for the fetus to be excreted: under the influence of hormones, the tissues of the walls change, become more elastic. As practice shows, this allows the vagina to stretch as much as necessary so that the child freely leaves the mother's womb.
3. Protective.  It is expressed in the fact that the vagina of a woman, including a virgin, is a kind of barrier. The structure of the vagina is such that it provides self-cleaning of the body, while preventing the entry and development of other microorganisms. As previously mentioned, it is the walls of the vagina that help to perform this function in a woman's body.

   Some girls and women, unknowingly, incorrectly implement the rules of intimate hygiene, thereby violating the normal microflora of internal organs. This happens in cases when frequent douching is practiced with water or, even worse, with antibacterial agents. If the microflora is normal and abundant discharge does not bother, this should not be done.

4. Output.  This internal organ of the female body is, as previously mentioned, a channel. However, it is intended not only to contribute to the conception of a child and his birth, but also to cleanse the body from the inside. The vagina helps to remove from the body of the fair sex (virgin, girl, woman) physiological secretions, which are the result of the body’s working capacity. This applies to both minor secretions of a transparent or whitish color, and menstruation.