How is the small pelvis arranged in women, and what can be seen in the photo in the anatomical atlas? How the human pelvis works The structure of the bones of the pelvis of a woman

The posterior wall of the rectum fills most of the sacral cavity. Part of the anterior wall of the rectum above the rectovaginal or rectovesical cavity is covered with peritoneum (Fig. 6). The posterior recess of the peritoneum has an almost vertical direction, however, the anterior wall of the rectum partially hangs over this recess.

Wind G. J.

Applied laparoscopic anatomy: abdomen and pelvis

The pelvis is a part of the skeleton that provides attachment to the body of the lower limbs and serves as a container and protection for a number of important internal organs. The male and female pelvis are similar in structure, but in women it allows them to carry and protect the fetus during pregnancy. Problems in the weaker sex occur much more often, the pelvic organs now and then make themselves felt. This is due to the structural features of the female body, into which infections and viruses penetrate more easily.

3. Diseases of the uterus (erosion, endometriosis, etc.).

4. Inflammation of the appendages.

5. Ovarian cyst.

6. Diseases of the bladder (for example, cystitis).

In women, everything in the body is interconnected, so the disease of one organ often affects another.

endometriosis and endometritis


The pelvic organs play a primary role in pregnancy and childbirth. Some women experience inflammation of the lining of the uterus (endometritis). It is a consequence of neglected infectious diseases, miscarriages or abortions. Also, inflammation can occur when using local contraceptives (for example, when installing a spiral). Pay attention to your health, monitor your discharge, and occasionally feel your pelvic organs to make sure everything is in order. Endometriosis is manifested in the growth of uterine tissue to other organs. It can lead to infertility, so it should be detected in the early stages. The main symptom of endometriosis is pain in the lower abdomen, menstruation disorders. Endometriosis discharges are blood clots. In some cases, surgery is required. To exclude diseases or identify them in the early stages, you should regularly visit a gynecologist. The pelvic organs are a thing that cannot be trifled with. Since even minor pain can be a sign of a serious illness.

Vaginitis and other diseases of the vagina

Inflammation of the vagina occurs in the presence of any harmful factors. For example, your man's poor hygiene, a constant allergy to condoms. Also, vaginitis occurs with untreated or ignored thrush, chlamydia. In no case should you have sex in the presence of these problems, since the physical impact on the irritated walls of the vagina leads to the appearance of wounds and microcracks, as a result, everything develops into vaginitis. With recurrent thrush, you should consult a doctor, since self-medication can only lead to a worsening of the condition. Often, thrush passes to the uterus and other organs of the small pelvis. Then it will be very difficult to get rid of it. If thrush appears rarely and is always associated with hypothermia, malnutrition, or taking antibiotics, then you should not panic. The easiest treatment option is 1 fluconazole capsule. Of the folk methods of struggle - douching and washing with soda solution, decoction of chamomile or plantain.

All components of the human body are uniquely thought out by nature and clearly perform their functions, whether it is the structure of the femur or pelvis. This part of the body is a lower limb girdle, which has hip joints on both sides. This part of the skeleton is a kind of continuation of the spine and performs many tasks in humans. It is necessary to understand the structural features of the human pelvis, because, despite the similarity, its anatomy in women and men is different.

Building without details

In total, two components can be named - this is the sacrum and two nameless bones, which are also called the pelvic. They are connected by inactive joints, which are reinforced with ligaments. There is an entrance and exit, which is covered with muscles, these features are more important in women, because they have an impact on the course of childbirth. There are many holes through which the vessels and nerves pass. With the help of the nameless pelvic bones, it is limited in front and from the sides. Behind the limitation is the coccyx, which is a continuation of the spine.

Unnamed pelvic bones

The structure of these pelvic bones is unique in its kind, since they are three more bones that have joints until the age of 16, and then grow together, which is confirmed by x-ray anatomy. This joint fuses in the region of the acetabulum, the name of which is translated from Latin as acetic acid. In the area of ​​\u200b\u200bthis formation is the hip joint, which in humans is strengthened by ligaments and with the help of muscles. Components of the innominate bone:

  • iliac;
  • pubic;
  • ischial.

The ilium has a body located in the region of the acetabulum, as well as a wing. On the inner surface, it has a concavity, the shape is due to the fact that intestinal loops are located here. An unnamed line passes below, which limits the entrance to the small pelvis and serves as a guide for doctors in humans, this applies to women. There are three lines along the outer surface - the place of attachment of the gluteal muscles. A crest runs along the edge of the wing, which ends with the anterior and posterior, upper iliac bones, it has an outer and inner edge. There are superior and inferior, anterior and posterior iliac bones, which in humans are important anatomical landmarks.

The second bone that has a body in the region of the acetabulum is the pubis. It has two branches and forms another joint - pubic symphysis. This formation is called a semi-joint, because it has some signs of a joint, there are no movements or in the form of sliding, however, it diverges during childbirth, increasing the pelvic cavity. The upper branch runs horizontally, while the lower branch runs vertically. Connecting with the ischium, they limit the obturator foramen.

The pubic symphysis is strengthened by ligaments, which are called the upper and lower longitudinal. Sometimes during childbirth their rupture occurs, as shown by x-ray anatomy in the produced image. The upper branch is the limiter of the entrance to the pelvic cavity in humans. The lower one limits the exit plane.

The third bone is the ischium, its body, it fuses in the region of the acetabulum of the hip joint. One process departs from the body, which has a tubercle, it is on it that a person leans while sitting.

Sacrum

In ancient times, the sacrum was considered a sacred bone and therefore got its name in Latin - sacrum, which translates as sacred. This bone, no doubt, can be called a continuation of the spine. Outwardly, it resembles a spine, but one that has grown together. In humans, these are five vertebrae, which have a smooth surface in front, in anatomy it is called the pelvic. Traces of fusion are visible on this surface, and there are also holes through which nerves enter the pelvic cavity in a person.

The back surface is uneven, has bulges characteristic of this part of the spine. These irregularities serve to attach muscles and ligaments. The sacrum is connected to the innominate bones with the help of joints reinforced with ligaments. Ahead there is the most protruding part, which is a cape and serves as a guide for a person during a study at a gynecologist's appointment.

The sacrum ends with the coccyx, which is a section of the spine, and includes from 3 to 5 vertebrae. During childbirth, it is pushed back, allowing the baby to be born without problems. It also has attachment points for the pelvic floor muscles.

Difference of the pelvis

In a woman, the bone component and internal organs have some features. The female pelvis performs important functions - it participates in childbirth. In this aspect, not only its clinical and X-ray anatomy, but also its shape matters for the doctor. In women, the pelvis is wider and lower, the hip joints are located at a wider distance, the bones do not differ in thickness. The shape of the sacrum in the male pelvis is narrower and more concave, the promontory and lower spine protrude more forward. In the female pelvis, the opposite is true: the sacrum is wide and does not protrude forward so much.

The shape of the pubic angle in men is sharp and ranges from 70 to 75 cm, in women it is more straight and ranges from 90 to 100 cm, the wings in the female pelvis are deployed, and the buttocks are at a distance. A landmark in a person can serve as protrusions of the bone. Thus, in women, the distance between the anterior-upper bones ranges from 25 to 27 cm, while in men it averages 22-23 cm.

The plane of entry and exit from the small pelvis in women is larger; on top, the opening in women resembles a transverse oval, while in men it is longitudinal. Yes, and the volume is greater in the female pelvis, which is associated with childbirth. There are also features in the angle of inclination. In the female pelvis, it is 55-60 degrees, while in the male - 50-55 degrees.

For human pelvic bones, the size of the entrance and exit to the small pelvis matters. The entrance to gynecology is the distance between the upper edge of the symphysis and the most protruding point of the promontory. The exit is determined from the edge of the coccyx to the lower edge of the symphysis. The transverse dimensions are located on top at the farthest points of the innominate line, the lower ones are between the ischial tubercles.

The sex of the pelvic bones of the skeleton can be easily determined, this circumstance is used during excavations in archeology or during forensic examination, when only the skeleton is the task of establishing who it belonged to. The dimensions of the pelvis are taken into account by obstetricians during childbirth and in their planning. If the dimensions are distorted or insufficient, then delivery is carried out operatively, through caesarean section. The dimensions of the pelvis are established and recorded in the pregnant woman's card at her first visit to the antenatal clinic. In men, the pelvis has no such significance.

Perineal muscles

The exit from the small pelvis is called the perineum and is closed by muscles that matter to a woman because they take part in the process of childbirth. The male perineum, like the female, is responsible for the act of defecation, urination and the function of the genital organs. The human perineum consists of the pelvic floor muscles, the levator anus, and the external sphincter. There are also several muscles that affect sexual function, promote erection, narrow the entrance to the vagina, for example, ischiocavernosus.

Organs that are in the pelvis

The structure of this part of the human body cannot be imagined without pelvic organs.

In the cavity of the large pelvis, these are intestinal loops; during pregnancy, the uterus and the fetus in it are located here. Also in the right iliac region on the right side of a person is an appendix, although the options for its location may be different.

In women and men in the pelvic cavity there are some features of the genital organs. The bladder and urethra are present in both sexes, as are the rectum and part of the large intestine. Vessels, nerves, part of the muscles of the joints pass near the spine. Nerve plexuses and lymph nodes are located near the pelvic spine.

In the pelvis of a man there is a prostate covering the urethra, it consists of muscles, next to it are the seminal vesicles, as well as the vas deferens.

Among the pelvic organs, a woman has the ovaries, which are made up of muscles, the fallopian tubes, the uterus, her cervix, and the vagina. Moreover, the cavity of the female genital organs communicates with the abdominal cavity, which is fraught with the spread of infection. The space between the organs is occupied by fiber. Near the rectum, this fiber in some cases becomes inflamed, causing paraproctitis.

Blood supply and nerve plexuses

The sacral and coccygeal nodes are considered the most important in practice. Some nerves emerge from the spinal canal and enter the pelvic cavity as independent nerves.

Also near the spine are arteries and veins. The largest are the common iliac arteries extending from the aorta. From them, on each side, the outer one branches off, it goes to the thigh, and the inner one, which supplies the organs of the small pelvis, the iliac arteries. The outflow of blood is carried out through the veins of the same name into the superior vena cava.

The anatomy of the pelvis is very complex, in addition to being the seat of internal organs, it also bears the load during walking and distributes it. Any curvature of the pelvic bones in women can affect the success of childbirth, the ability to bear a fetus. In both sexes, the curvature, for example, after an injury, can cause lameness, soreness, or disruption of the pelvic organs, it is the anatomy that helps to establish the cause in such cases.

Knowledge of every detail of the structure of the pelvis allows you to make a diagnosis, to understand the cause of the development of a particular disease. In some cases, structural features are used for examination in order to establish gender. Information about the structure of the pelvis is also required during the examination and reading of x-rays.

Reproduction is the main purpose of all life on our planet. To realize this goal, nature has endowed people with special organs, which we call reproductive. In women, they are hidden in the pelvis, which provides a favorable environment for the development of the fetus. Let's talk on the topic - "The structure of the female pelvic organs: a diagram."

The structure of the female organs located in the small pelvis: diagram

In this area of ​​\u200b\u200bthe female body, the reproductive and urogenital organs are located:

  • ovaries, the main purpose of which is the production of eggs;
  • fallopian tubes, through which eggs are delivered to the uterus for fertilization by male sperm;
  • vagina - entrance to the uterus;
  • urinary system, consisting of the bladder and urethra.



The vagina (vagina) is a muscular tube that extends from the entrance, hidden behind the labia, to the cervical region of the uterus. That part of the vagina that surrounds the uterine neck, forms a vault, conditionally consisting of four sectors: posterior, anterior, as well as left lateral and right.

The vagina itself consists of walls, which are also called posterior and anterior. The entrance to it is covered by the outer labia, forming the so-called vestibule. The vaginal opening is also known as the birth canal. It is used to remove secretions during menstruation.


Between the rectum and the bladder (in the middle of the small pelvis) is the uterus. It looks like a small, hollow, pear-shaped muscle bag. Its function is to ensure the nutrition of the fertilized egg, the development of the embryo and its gestation. The bottom of the uterus is located above the entry points of the fallopian tubes, and her body is located below.

The narrow part protruding into the vagina is called the cervix. It has a spindle-shaped cervical passage, which begins on the inside of the uterus with a pharynx. The part of the canal that goes into the vagina forms the external pharynx. In the peritoneal cavity, the uterus is attached through several ligaments, such as round, cardinal, wide left and right.


A woman's ovaries are connected to the uterus through the fallopian tubes. In the peritoneal cavity on the left and right they are held by wide ligaments. Pipes are a paired organ. They are located on both sides of the uterine fundus. Each tube begins with a hole resembling a funnel, along the edges of which are fimbria - finger-shaped protrusions above the ovary.

The widest part of the pipe departs from the funnel - the so-called ampoule. Tapering along the tube, it passes into the isthmus, which ends in the uterine cavity. After ovulation, a mature egg moves along the fallopian tubes from the ovary.


The ovaries are a pair of female sex glands. Their shape resembles a small egg. In the peritoneum, in the pelvic area, they are held by their own ligaments and partly due to the wide ones, they have a symmetrical arrangement relative to the uterine body.

The narrower tubular end of the ovaries is turned towards the fallopian tube, and the wide lower edge faces the uterine fundus and is attached to it by means of its own ligaments. The fimbriae of the fallopian tubes cover the ovary from above.

The ovary contains follicles inside which eggs mature. As it develops, the follicle moves to the surface and, in the end, breaks through, releasing a mature egg into the abdominal cavity. This process is called ovulation. She is then captured by the fimbriae and sent on her journey through the fallopian tubes.


In women, the urinary duct connects the internal opening of the bladder to the external urethral opening next to the vulva. It runs parallel to the vagina. Near the external urethral opening, two paraurethral ducts flow into the canal.

Thus, in the urethra, three main parts can be conditionally distinguished:

  • internal opening of the urinary duct;
  • intra-wall part;
  • outer hole.


Possible anomalies in the development of organs in the pelvis in women

Anomalies in the development of the uterus are common: they occur in 7-10% of women. The most common types of uterine anomalies are caused by incomplete fusion of the Müllerian ducts and are:

  • with complete nonunion of the ducts - a double vagina or uterus;
  • with partial nonunion, the so-called bicornuate uterus develops;
  • the presence of intrauterine partitions;
  • arcuate uterus;
  • an asymmetric unicornuate uterus due to a delay in the development of one of the Müllerian ducts.

Variants of vaginal anomalies:

  • vaginal infertility - most often occurs due to the absence of the uterus;
  • vaginal atresia - the lower wall of the vagina consists of fibrous tissue;
  • Müllerian aplasia - the absence of the vagina and uterus;
  • transverse vaginal septum;
  • intravaginal urethral outlet;
  • anorectal or vaginorectal fistula.

There are also anomalies in the development of the ovaries:

  • Turner's syndrome - the so-called infantilism of the genital organs, caused by chromosomal abnormalities, which leads to infertility;
  • development of an additional ovary;
  • absence of fallopian tubes;
  • displacement of one of the ovaries;
  • hermaphroditism - a condition when a person has both male testicles and female ovaries with a normal structure of the external genital organs;
  • false hermaphroditism - the development of the gonads occurs according to one type, and the external organs - according to the opposite sex.

In the medical literature, the intricate definition of the concept of the small pelvis in women is accompanied by a photo or picture, where the names of organs and bones are signed in Latin. It is difficult for a person who is far from medicine to understand the meanings of these terms and to delve into medical terminology, but this knowledge, at times, turns out to be very useful. So what hides a woman's small pelvis?

The pelvis refers to the girdle of the lower extremities. Responsible for a reliable skeletal connection of the legs with the body due to the bone-ligamentous base of the pelvis and hip joints.

It consists of two pelvic bones, each of which is usually divided into three parts:

  • iliac;
  • ischial;
  • pubic.

Until about the age of 16, such a division is due to the fact that the pelvic bone is divided by cartilage into 3 parts with similar names. As they grow older, the cartilages ossify, thereby forming a single bone plate, and such a gradation remains and is more of a conditional character.

In the center of the ilium on the outer surface is the acetabulum - a deep hemispherical depression necessary for articulation with the femoral head.

Fact! Due to this, a strong connection of the upper body with the lower limbs is formed, which is also necessary for the performance of the motor function.

The bone ring is formed by the connection of two pelvic bones with the sacrum and coccyx. The border in this case will be the so-called borderline or, as it is also called, the nameless line. Its conditional location can be determined by the following bones:

  • iliac (arc-shaped lines);
  • sacrum (his cape);
  • pubic (their crests);
  • pubic symphysis (upper edge).

What is above is the upper section, also called the large pelvis, respectively, the narrow pelvis is located below, which has other names - narrow, true.

Bone borders of the pelvis

There is a bone restriction of the large pelvis only on three sides, it is absent in front. On the sides of its borders define the ilium, behind - the vertebrae of the lumbar spine.

The structure of the small pelvis includes more bones. It includes:

  1. In front - the pubic articulation (pubic symphysis), which is a semi-movable connection of the pubic bones.
  2. On the sides are the wings of the ilium.
  3. Behind - sacrum and coccyx.

Such atypical structure of the small pelvis allows it to perform the following functions:

  1. Maintain balance.
  2. Distribute the high load of the upper body.
  3. Serve as a support for the spine.

In addition, the pelvis is a protective structure for the internal organs, and the skeleton of the female pelvis differs from the male. This is due to the fact that women are genetically programmed to perform the reproductive function, that is, to carry and give birth to a child.

The structure of the female pelvis has its own anatomical features:

  1. His bones are much thinner and do not differ in such massiveness as those of the male.
  2. A wide and less concave sacrum, the cape protrudes less forward compared to the male.
  3. Wide and short symphysis.
  4. The wide entrance to the small pelvis has a transverse-oval shape, and a notch is located in the region of the promontory of the sacrum.
  5. The pubic angle reaches 90-100°.
  6. The coccyx protrudes less forward than in men.

The pelvis of women is larger and wider, but not as deep as that of men.

The cavity formed inside the joints of the bones serves as a kind of receptacle for several vital organs.

If you do not go into anatomical details, then in the small pelvis are the organs of the reproductive and digestive systems. They are very closely located among themselves and are surrounded on all sides by muscles and ligaments, which provide them with an anatomically correct position. The fibrous muscles of the perineum and the dense muscles of the pelvic diaphragm form the pelvic floor.

Interesting! The pelvic floor is in constant tone. It can, if necessary, contract or stretch - this happens, for example, during urination or in the process of coughing.

Vagina

This is an internal organ, which is an elastic muscular tube. Its upper part connects to the cervix, the lower part passes into the vestibule of the vagina, which is surrounded by the following organs:

  1. Clitoris.
  2. Large (external) labia.
  3. Small (inner) labia.

The entrance to the vagina is located in the middle between the urethra, located in front, and the rectum at the back. For virgins, the entrance is closed by the hymen. She may have one or more holes for menstrual flow.

ovaries

This is a female sex steam gland, which has an average weight of about 7 grams. They are attached to the uterus with ligaments and are mobile organs - their topography depends on the size and position of the uterus.

It is from here, from the ovaries, that the mature eggs begin their journey through the fallopian tubes, in which they are fertilized. After that, they continue to move towards the uterus, where the fetus will grow and develop until childbirth. If fertilization does not occur, the next cycle of menstruation begins.

The fallopian tubes

Otherwise they are called - fallopian tubes. This is a paired organ that connects the uterus and ovaries. The main task is to transport the eggs to the uterus and create a favorable environment for the fertilization of the egg.

Muscular hollow organ. Its front surface borders on the bladder, and the back - on the rectum. The slope of the uterus directly depends on the filling of these organs.

The walls of the uterus are multi-layered and extensible, which allows it to change its size along with the growth of the child during pregnancy. When the pregnancy comes to an end - the uterus, like a muscular organ, begins to contract, directing the child to its lower part - the neck. That, in turn, increases in size and opens to release the child into the birth canal and give rise to the birth process itself.

Bladder

Hollow organ of the urinary system. In addition to cumulative, it performs the function of excreting urine, it is located behind the pubis. The bladder is a muscular organ, so it can increase due to the fluid entering it from the kidneys up to 650 ml, after which the brain receives a signal to remove urine.

Rectum

This is the final part of the digestive system, located in the small pelvis. It is named so because of the absence of bends. At this site, the process of splitting the remaining food and the absorption of nutrients ends, and the accumulation of feces begins to further bring them out.

PID

PID is an inflammatory disease of the pelvic organs, the causes of which are many, but there are similar symptoms:

  1. Itching and swelling of the external genitalia.
  2. Discharge: purulent or simply profuse.
  3. The appearance of pain in the lower abdomen is not clear origin.
  4. Painful urination.
  5. Pain that occurs during intercourse.
  6. irregular cycle.

The presence of even one or two of these symptoms is a reason to go to the gynecologist and identify the causes of the disease. To do this, you will need to pass tests and undergo certain studies, which are assigned individually, depending on each specific situation. The World Health Organization estimates that 40% of women who leave their infections untreated will develop PID. And every fourth will face infertility.

During therapy, conservative treatment is most often used. After the end of therapy, a second study is carried out to monitor the patient's condition. There are cases when surgical intervention is necessary, for example, when removing pus or uterine appendages. After such surgical procedures, physiotherapy and drug treatment are prescribed, aimed at restoring the normal environment of the vagina and strengthening the immune system. Prevention of PID is safe sex and proper selection of contraception.


The bone pelvis is a strong container for the internal hollow organs and their surrounding tissues. The woman's pelvis forms the birth canal through which the fetus is born.

Differences between the female pelvis and the male pelvis begin to emerge during puberty and become distinct in adulthood.

The bones of the female pelvis are thinner, smoother and less massive than the bones of the male. The female pelvis is lower, wider and larger in volume. The sacrum in women is wider and less concave than in men. The symphysis in women is shorter and wider. The cape of the sacrum protrudes less forward. The entrance to the small pelvis in women is more extensive and has a transverse-oval shape with a notch in the region of the cape of the sacrum, while in men it resembles the shape of a card heart due to the sharp protrusion of the cape. The pelvic cavity in women is more extensive and in shape approaches the cylinder, curved anteriorly. In men, the pelvic cavity is smaller, and it narrows downwards in a funnel-shaped manner. The exit of the pelvic cavity in a woman is wider, since the distance between the ischial tubercles is greater. The pubic angle is wider (90-100) than in men (70-75). And the coccyx protrudes anteriorly less than in the male pelvis

Thus, we can conclude that the female pelvis is more voluminous and wider, but less deep than the male.


Pelvic bones

The pelvis is made up of four bones: two pelvic bones, the sacrum, and the coccyx.

Pelvic (nameless) bone (os coxae ). Up to 16-18 years, it consists of three bones connected by cartilage: iliac, ischial and pubic. After ossification, the cartilages fuse together to form the innominate bone.

Ilium ( os ilium ) has two parts: body and wing. The body makes up a short, thickened part of the bone and participates in the formation of the acetabulum.


Large pelvis dimensions

Knowing the size of the external pelvis is very important in obstetrics, since the size of the small pelvis is judged by its size. The measurement is made with a tazometer. There are four sizes: three transverse and one straight.

Distantia spinarum- distance between the anterior superior iliac spines.It is usually equal to 25-26 cm.


Distantia cristarum- the distance between the most distant points of the iliac crests. Usually it is 28-29 cm.


Distantia trochanterica -distance between the greater trochanters of the femur. It is 30-31 cm.


Conugata externa -external conjugate i.e. straight size of the pelvis. The woman is laid on her side, the underlying leg is bent at the knee and hip joints, the overlying one is pulled out. The button of one branch of the tazomer is set in the middle of the upper outer edge of the symphysis, the other end is pressed against the supra-sacral fossa, which is located between the spinous process of the 5th lumbar vertebra and the beginning of the middle sacral crest (the supra-sacral fossa coincides with the upper angle of the sacral crest). Normally, it is 20-21 cm .


Conugata vera-true conjugate. To determine it, it is necessary to subtract 9 from the outer conjugate, then we get the true size. The difference between the true and external conjugates depends on the thickness of the sacrum, symphysis and soft tissues, so the difference does not always correspond exactly to 9 cm. Or 1.5-2 cm is subtracted from the size of the diagonal conjugate.


Conugata diagonalis -- diagonal conjugate - this is the distance from the lower edge of the symphysis to the most prominent point of the promontory of the sacrum. It is determined by vaginal examination. With a normal pelvis, it is 12.5-13 cm.

Taking into account the danger of pelvic presentation of the fetus in the mother's pelvis, timely diagnosis, hospitalization of a woman in an obstetric hospital at 35-36 weeks of gestation is very important. fetus in the mother's pelvis by caesarean section. Indications for the operation of turning the fetus on the leg are: full disclosure of the cervix and discharge of water during examination or in a timely manner. The operation of turning the fetus on the leg is performed under deep anesthesia. Categorical contraindications for this operation are: premature, early discharge of amniotic fluid and incomplete opening of the cervix.

1. TOPIC OF THE LESSON: PELVIS FROM THE OBSTETRIC POINT OF VIEW: DIMENSIONS OF THE LARGE PELVIS, THE SMALL PELVIS, ITS PLANES AND DIMENSIONS. FETUS AS AN OBJECT OF BIRTH: HEAD OF THE FETUS, BONES OF THE SKULL, SUMS AND FELLOWS. DIMENSIONS OF THE HEAD OF THE TERM FETUS. POSITION OF THE FETUS IN THE UTERUS.

2. Form of organization of the educational process: a practical lesson.

3. Meaning of the topic(relevance of the problem under study): Knowledge of anatomical formations, the size of a normal pelvis, the average size of the fetus is necessary for further study of obstetrics.

4. Learning objectives:

4.1. common goal: study of the anatomy of the pelvis and structural features of the fetus; obstetric terminology.

4.2. learning goal: the student must know the structure of the pelvis of a woman and the head of the fetus; measure the pelvis and head of the fetus, as well as timely diagnose deviations in the structure and size of the pelvis.

4.3. Psychological and pedagogical goal: Knowledge of the anatomical features of the structure of the bone pelvis, allows the doctor to determine the tactics of pregnancy and childbirth.

The student must know:

    the structure of the bone pelvis;

    pelvic planes, their boundaries and sizes, diagonal, anatomical and true conjugates;

    wire axis and angle of inclination of the pelvis;

    muscles and fascia of the pelvic floor;

    the structure of the skull of a full-term fetus, sutures, fontanelles and the size of the head, shoulder and pelvic girdle of the fetus;

    basic obstetric terms (articulation, position, fetal axis, presentation, position and appearance);

    signs of pregnancy (doubtful, probable, reliable), methods for diagnosing pregnancy, hormonal tests.

The student must be able to:

    show on the model of the female pelvis the boundaries of the planes of the small pelvis, the identification points of the anatomical and true conjugates;

    four ways to determine with vera;

    show the sutures and fontanelles on the head of a full-term fetus (doll);

    size of the head of a full-term fetus, signs of full-term;

    on the phantom, give the doll a certain position, position, appearance, presentation;

    determine the gestational age by various methods.

5. Place of the practical lesson: department of pathology of pregnancy, maternity department, study room, methodical office.

6. Equipment for the lesson:

1. Tables

2. A set of tickets to control the initial level of knowledge of students.

3. A set of tickets to control the final knowledge of students.

4. Obstetric simulator with a doll.

5. Model of the bone pelvis.

6. Model "Doll".

7. Tazomer, measuring tape.

8. Obstetric stethoscope.

8. Annotation of the topic(summary)

Of great importance in obstetrics is the bone pelvis, which forms a solid foundation for the birth canal. The pelvic floor, stretching, is included in the birth canal and contributes to the birth of the fetus.

Female pelvis (bone pelvis)

Bone pelvis It is a strong container for the internal genital organs of a woman, the rectum, bladder and surrounding tissues. The woman's pelvis forms the birth canal through which the fetus is born. The development and structure of the pelvis is of great importance in obstetrics.

The pelvis of a newborn girl differs sharply from the pelvis of an adult woman, not only in size, but also in shape. The sacrum is straight and narrow, located vertically, the cape is almost absent, its area is located above the plane of the entrance to the pelvis. The entrance to the small pelvis has an oval shape. The wings of the ilium are steep, the pelvis narrows significantly towards the exit. As the body develops, the volume and shape of the pelvis changes. The development of the pelvis, as well as the whole organism as a whole, is determined by environmental conditions and hereditary factors. The formation of the pelvis in childhood is particularly influenced by the effects associated with sitting, standing, walking. When the child begins to sit, the pressure of the trunk is transferred to the pelvis through the spinal column. When standing and walking, pressure from the lower extremities joins the pressure on the pelvis from above. Under the influence of pressure from above, the sacrum moves somewhat into the pelvis. There is a gradual increase in the pelvis in the transverse direction and a relative decrease in the anteroposterior dimensions. In addition, the sacrum, under the influence of pressure from above, rotates around its horizontal axis so that the cape descends and begins to protrude into the entrance to the pelvis. In this regard, the entrance to the pelvis gradually takes the form of a transverse oval with a notch in the promontory area. When the sacrum is rotated around the horizontal axis, its tip should have moved backward, but it is held by the tension of the sacrospinous and sacrotuberous ligaments. As a result of the interaction of these forces, a curve of the sacrum (sacral cavity) is formed, which is typical for the pelvis of an adult woman.

Differences between the female and male pelvis begin to be detected during puberty and become distinct in adulthood:

1. the bones of the female pelvis are thinner, smoother and less massive than the bones of the male pelvis;

2. the female pelvis is lower, wider and larger in volume;

3. the sacrum in women is wider and not as strongly concave as in the male pelvis;

4. the sacral promontory in women protrudes less than in men;

5. the symphysis of the female pelvis is shorter and wider;

6. the entrance to the small pelvis in a woman is more extensive, the shape of the entrance is transversely oval, with a notch in the cape area; the entrance to the male pelvis resembles a card heart due to the sharper protrusion of the promontory;

7. The pelvic cavity in women is more extensive, in its outline it approaches a cylinder, curved anteriorly; the cavity of the male pelvis is smaller, it narrows downwards like a funnel;

8. the exit of the female pelvis is wider because the distance between the ischial tubercles is greater, the pubic angle is wider (90-100 0) than in men (70-75 0); the coccyx protrudes anteriorly less than in the male pelvis.

Thus, the female pelvis is more voluminous and wide, but less deep than the male pelvis. These features are important for the birth process.

The development of the pelvis can be disrupted under adverse conditions of intrauterine development associated with diseases, malnutrition and other disorders in the mother's body. Severe debilitating diseases, unfavorable living conditions during childhood and puberty can lead to a delay in the development of the pelvis. In such cases, features characteristic of the childish and youthful pelvis may persist until the woman's puberty.

PELVIC BONES

The pelvis consists of four bones: two pelvic (or innominate), sacrum and coccyx.

Pelvic (innominate) bone(os coxae, os innominatum) up to 16-18 years old consists of three bones connected by cartilage: iliac, pubic and ischial. After ossification of the cartilage, these bones fuse together to form the innominate bone.

Ilium(os ilium) consists of two parts: the body and the wing. The body makes up a short, thickened part of the ilium, it participates in the formation of the acetabulum. The iliac wing is a fairly wide plate with a concave inner and convex outer surface. The most thickened free upper edge of the wing forms iliac crest(crista iliaca). In front, the ridge begins with a ledge ( anterior superior spine- spina iliaca anterior superior), below is the second protrusion (front-lower spine - spina iliaca anterior inferior). Under the anteroinferior axis, at the junction with the pubic bone, there is a third elevation - iliopubic tubercle(tuberculum iliopubicum). Between the anteroinferior and anteroinferior iliac spine is the lesser iliac notch, between the anteroinferior spine and the iliopubic tubercle is the greater iliac notch. The iliac crest ends behind posterior superior iliac spine(spina iliaca posterior superior), below which is the second protrusion - the posterior iliac spine (spina iliasa posterior inferior). Under the posterior spine is a large sciatic notch (incisura ischiadica major). On the inner surface of the ilium, in the area of ​​​​the transition of the wing to the body, there is a ridge-like protrusion that forms an arcuate border, or nameless line (linea terminalis, s innominata). This line runs from the sacrum across the entire ilium, in front passes to the upper edge of the pubic bone.

Ischium(os ischii) has a body involved in the formation of the acetabulum, and two branches: upper and lower. The upper branch goes down from the body and ends ischial tuberosity(tuber ischiadicum). On the back surface of the lower branch there is a protrusion - ischial spine(spina ischiadica). The lower branch goes anteriorly and upwards and connects with the lower branch of the pubic bone.

Pubic bone, or pubic (os pubis), forms the front wall of the pelvis. The pubic bone consists of a body and two branches: the upper (horizontal) and the lower (descending). The short body of the pubic bone forms part of the acetabulum, the lower branch is connected to the corresponding branch of the ischium. On the upper edge of the upper (horizontal) branch of the pubic bone, there is a sharp crest, which ends in front with a pubic tubercle (tuberculm pubicum). The upper and lower branches of both pubic bones are connected to each other in front by means of a sedentary pubic articulation (connection) - symphysis(symphisis). Both pubic bones are connected in the symphysis by an intermediate cartilage, in which there is often a small slit-like cavity filled with fluid; during pregnancy, this gap increases. The lower branches of the pubic bones form an angle under the symphysis, which is called the pubic arch. The connecting branches of the pubic and ischial bones limit the rather extensive obturator foramen (foramen obturatorium).

Sacrum(os sacrum) consists of five fused vertebrae. The size of the sacral vertebrae decreases downward, so the sacrum has the shape of a truncated cone. Its wide part - the base of the sacrum - is turned up, the narrow part - the top of the sacrum - down. The posterior surface of the sacrum is convex, the anterior is concave, it forms the sacral cavity. On the anterior surface of the sacrum (in the cavity), four transverse rough lines are visible, corresponding to the ossified cartilaginous joints of the sacral vertebrae. The base of the sacrum (the surface of the 1st sacral vertebra) articulates with the 5th lumbar vertebra; a protrusion is formed in the middle of the anterior surface of the base of the sacrum - sacral promontory(promontory). Between the spinous process of the 5th lumbar vertebra and the beginning of the middle sacral crest, it is possible to feel the cavity ( suprasacral fossa), which is used when measuring the pelvis.

Coccyx(os coccygis) consists of 4-5 fused vertebrae, is a small bone, tapering downwards.

The bones of the pelvis are connected through the symphysis, sacroiliac and sacrococcygeal joints. Cartilaginous layers are located in the joints of the pelvis. The joints of the pelvis are reinforced with strong ligaments. symphysis is a sedentary joint, semi-joint.

There are two sections of the pelvis: the upper - large pelvis - and the lower - the small pelvis. The boundaries between the large and small pelvis are: in front - the upper edge of the symphysis and pubic bones, from the sides - nameless lines, behind - the sacral cape. The plane lying between the large and small pelvis is the plane of entry into the small pelvis, this plane is of great importance in obstetrics.

LARGE pelvis

The large pelvis is much wider than the small one, it is bounded laterally by the wings of the ilium, behind by the last lumbar vertebrae, and in front by the lower abdominal wall. The volume of the large pelvis can change in accordance with the contraction or relaxation of the abdominal muscles. The large pelvis is available for research, its dimensions are determined and quite accurately. By the size of the large pelvis, the size of the small pelvis is judged, which is not available for direct measurement. Determining the size of the small pelvis is important, since the fetus passes through the unyielding bone canal of the small pelvis.

Usually four sizes of the pelvis are measured: three transverse and one straight.

1. Distantia spinarum (24-26 cm)

2. Distantia cristarum (27-29 cm)

3. Distantia trochanterica (30-31 cm)

4. Conjugata externa (20-21 cm)

By the size of the outer conjugate, one can judge the size of the true conjugate: 9 cm is subtracted from the length of the outer conjugate. The sacral rhombus (Michaelis rhombus) is also examined and measured.

SMALL pelvis

Determining the size of the small pelvis is important, because. through the stubborn bone canal of the small pelvis passes the fetus being born. The small pelvis has: an entrance, a cavity and an exit. In the pelvic cavity, a wide and narrow part is distinguished.

The planes and dimensions of the small pelvis. The small pelvis is the bony part of the birth canal. The posterior wall of the small pelvis consists of the sacrum and the coccyx, the lateral ones are formed by the ischial bones, the anterior - by the pubic bones and symphysis. The posterior wall of the small pelvis is 3 times longer than the anterior one. The upper part of the small pelvis is a solid, unyielding bone ring. In the lower part of the pelvic wall is not continuous; they have obturator openings and ischial notches, limited by two pairs of ligaments (sacrospinous and sacrotuberous).

In the 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: I - the plane of the entrance to the pelvis, II - the plane of the wide part of the cavity of the small pelvis, III - the plane of the narrow part of the pelvic cavity, IV - the plane of the exit of the pelvis.

I. The plane of the entrance to the small pelvis has the following boundaries: in front - the upper edge of the symphysis and the upper inner edge of the pubic bones, from the sides - nameless lines, behind - the sacral promontory. The entrance plane has the shape of a kidney or a transverse oval with a notch corresponding to the sacral promontory. At the entrance to the pelvis, three sizes are distinguished: straight, transverse and two oblique.

Straight size- the distance from the sacral cape to the most prominent point on the inner surface of the pubic joint. This size is called obstetric, or true, conjugate (conjugata vera). There is also an anatomical conjugate - the distance from the cape to the middle of the upper inner edge of the symphysis; the anatomical conjugate is slightly (0.3-0.5 cm) larger than the obstetric conjugate. Obstetric, or true conjugate is 11 cm.

Transverse dimension- the distance between the most distant points of the nameless lines. This size is 13-13.5 cm.

oblique dimensions two: right and left, which are equal to 12-12.5 cm. The right oblique size is the distance from the right sacroiliac joint to the left ilio-pubic tubercle, the left oblique size is from the left sacroiliac joint to the right ilio-pubic tubercle. In order to make it easier to navigate in the direction of the oblique dimensions of the pelvis in a woman in labor, M.S. Malinovsky and M.G. Kushnir offer the following reception. The hands of both hands are folded at a right angle, with the palms facing up; the ends of the fingers are brought closer to the outlet of the pelvis of the lying woman. The plane of the left hand will coincide with the left oblique size of the pelvis, the plane of the right hand with the right.

II. The plane of the wide part of the pelvic cavity has the following boundaries: in front - the middle of the inner surface of the symphysis, on the sides - the middle of the acetabulum, behind - the junction of the II and III sacral vertebrae. In the wide part of the pelvic cavity, two sizes are distinguished: straight and transverse.

Straight size- from the junction of II and III sacral vertebrae to the middle of the inner surface of the symphysis; equal to 12.5 cm.

Transverse dimension- between the tops of the acetabulum; equal to 12.5 cm.

There are no oblique dimensions in the wide part of the pelvic cavity because in this place the pelvis does not form a continuous bone ring. Oblique dimensions in the wide part of the pelvis are allowed conditionally (length 13 cm).

III. The plane of the narrow part of the pelvic cavity bounded in front by the lower edge of the symphysis, laterally by the spines of the ischial bones, and behind by the sacrococcygeal articulation. There are two sizes: straight and transverse.

Straight size goes from the sacrococcygeal joint to the lower edge of the symphysis (apex of the pubic arch); equal to 11-11.5 cm.

Transverse dimension connects the awns of the ischial bones; equal to 10.5 cm.

IV. Pelvic outlet plane has the following boundaries: in front - the lower edge of the symphysis, from the sides - ischial tubercles, behind - the tip of the coccyx. The pelvic exit plane consists of two triangular planes, the common base of which is the line connecting the ischial tuberosities. In the outlet of the pelvis, two sizes are distinguished: straight and transverse.

Direct pelvic outlet size goes from the top of the coccyx to the lower edge of the symphysis; it is equal to 9.5 cm. When the fetus passes through the small pelvis, the coccyx departs by 1.5-2 cm and the direct size increases to 11.5 cm.

Transverse dimension of the pelvic outlet connects the inner surfaces of the ischial tubercles; is 11 cm. Thus, at the entrance to the small pelvis, the largest size is the transverse one. In the wide part of the cavity, the direct and transverse dimensions are equal; the largest size will be the conditionally accepted oblique size. In the narrow part of the cavity and the outlet of the pelvis, the direct dimensions are larger than the transverse ones.

The wire axis (line) of the pelvis. All planes (classical) of the small pelvis in front border on one or another point of the symphysis, and behind - on different points of the sacrum or coccyx. The symphysis is much shorter than the sacrum with the coccyx, so the planes of the pelvis converge in an anterior direction and fan-shaped diverge backwards. If you connect the middle of the direct dimensions of all the planes of the pelvis, you will get not a straight line, but a concave anterior (to the symphysis) line. This conditional line connecting the centers of all direct dimensions of the pelvis is called the wire axis of the pelvis. The wire axis of the pelvis is initially straight, it bends in the pelvic cavity in accordance with the concavity of the inner surface of the sacrum. In the direction of the wire axis of the pelvis, the fetus passes through the birth canal.

The angle of inclination of the pelvis (the intersection of the plane of its entrance with the plane of the horizon) when a woman is standing can be different depending on the physique and ranges from 45-55 0 . It can be reduced if the woman lying on her back is forced to pull the hips strongly to the stomach, which leads to the elevation of the womb. It can be increased by placing a roll-shaped hard pillow under the lower back, which will lead to the downward deviation of the womb. A decrease in the angle of inclination of the pelvis is also achieved if the woman is given a semi-sitting position, squatting.

PELVIC FLOOR

The exit of the pelvis is closed from below by a powerful muscular-fascial layer, which is called the pelvic floor. The part of the pelvic floor located between the posterior commissure of the labia and the anus is called the obstetric or anterior perineum (the posterior perineum is the part of the pelvic floor located between the anus and the coccyx).

The pelvic floor is made up of three layers of muscles covered by fascia:

I. Bottom (outer) layer consists of muscles converging in the tendon center of the perineum; the shape of the arrangement of these muscles resembles a figure eight suspended from the bones of the pelvis.

1. Bulbous-cavernous muscle(m.bulbo-cavernosus) wraps around the entrance to the vagina, attaches to the tendon center and the clitoris; when contracted, this muscle compresses the vaginal inlet.

2. Ischiocavernosus muscle(m.ischio-cavernosis) starts from the lower branch of the ischium and is attached to the clitoris.

3. Superficial transverse perineal muscle(m.transversus perinei superficialis) starts from the tendon center, goes to the right and left, is attached to the ischial tuberosities.

4. External sphincter of the anus(m.sphincter ani externus) - a muscle surrounding the end of the rectum. Deep bundles of muscles of the external sphincter of the anus begin at the top of the coccyx, wrap around the anus and end in the tendon center of the perineum.

II. Middle layer of pelvic muscles- the urogenital diaphragm (diaphragma urogenitale) occupies the anterior half of the exit of the pelvis. The urogenital diaphragm is a triangular muscular-fascial plate located under the symphysis, in the pubic arch. The urethra and vagina pass through this plate. In the anterior part of the urogenital diaphragm, muscle bundles surround the urethra and form its external sphincter; in the posterior section, muscle bundles are laid, running in the transverse direction to the ischial tuberosities. This part of the urogenital diaphragm is called the deep transverse perineal muscle. (m. transversus perinei profundus).

III. Upper (internal) the layer of muscles in the perineum is called the pelvic diaphragm (diaphragma pelvis). The pelvic diaphragm consists of a paired muscle that raises the anus (m.levator ani). Both broad muscles that lift the anus form a dome, the top of which is turned down and is attached to the lower rectum (slightly above the anus). The wide base of the dome is turned upwards and is attached to the inner surface of the walls of the pelvis. In the anterior part of the pelvic diaphragm, between the bundles of muscles that lift the anus, there is a longitudinally located gap through which the urethra and vagina (hiatus genitalis) exit the pelvis. The muscles that lift the anus consist of separate muscle bundles starting from various sections of the pelvic walls; this layer of pelvic muscles is the most powerful. All muscles of the pelvic floor are covered with fascia.

In childbirth, the perineum is often injured, while it is the inner layer of the pelvic floor that is damaged.

The muscles and fasciae of the pelvic floor perform the following important functions:

1. The pelvic floor is a support for the internal genital organs, helps to maintain their normal position. Of particular importance are the muscles that lift the anus. With the contraction of these muscles, the genital gap closes, the lumen of the rectum and vagina narrows. Damage to the muscles of the pelvic floor leads to prolapse and prolapse of the genitals.

2. The pelvic floor is a support not only for the genitals, but also for the viscera. The pelvic floor muscles are involved in the regulation of intra-abdominal pressure together with the abdominal obstruction and the muscles of the abdominal wall.

3. During childbirth, when the fetus is expelled, all three layers of the pelvic floor muscles stretch and form a wide tube, which is a continuation of the bone birth canal. After the birth of the fetus, the pelvic floor muscles contract again and return to their previous position.

It forms a generic the channel through which the fetus moves. Unfavorable conditions for intrauterine development, diseases suffered in childhood and inpuberty, can lead to disruption of the structure and developmentpelvis. The pelvis can be deformed as a result of trauma, tumors, various exostoses. 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 those of the male. pelvis. The plane of the entrance to the small 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. The pubic symphysis in the female pelvis is shorter than the male. The sacrum in women is wider, the sacral cavity is moderately concave. The pelvic cavity in women approaches the cylinder in outline, while in men it narrows downwards in a funnel-shaped manner. The pubic angle is wider (90-100°) than in men (70-75°). The coccyx protrudes anteriorly less than in the male pelvis. The ischial bones in the female pelvis are parallel to each other, and converge in the male.

All of these features are very important in the process of childbirth. The pelvis of an adult woman consists of 4 bones: two pelvic, one sacral and one coccygeal, firmly connected to each other,

Pelvic bone, or nameless (os coxae, os innominatum), consists up to 16— 18 years of 3 bones connected by cartilage in the area of ​​the acetabulum(acetabulum): iliac (os ileum), sciatic (os ischii) and pubic (os pubis ). After puberty, cartilage fuses together and a solid bone mass is formed - the pelvic bone.

On the ilium distinguish between the upper section - the wing and the lower - the body.At the place of their connection, an inflection is formed, called arcuate or be-zymyanny line ( linea arcuata, innominata ). On the ilium follows from-mark a number of protrusions that are important to the obstetrician. Upper thickenedwing edge - iliac crest ( Crista Iliaca ) - has an arcuatecurved shape, serves to attach the broad muscles of the abdomen. Spere-di it ends with the anterior superior iliac spine ( spina iliaca anterior superior ), and behind - the posterior superior iliac spine ( spina iliaca posterior superior ). These two spines are important in determining the size of the pelvis.Ischium forms the lower and posterior thirds of the pelvic bone. She isconsists of a body involved in the formation of the acetabulum, and a branchischium. The body of the ischium with its branch makes an angle, openty anteriorly, in the region of the angle, the bone forms a thickening - the ischial tuberosity(tuber ischiadicum ). The branch goes anteriorly and upwards and connects with the lowerher branch of the pubic bone. On the back surface of the branch there is a protrusion - ischial spine (spina ischiadica). On the ischium, there are two tenderloin: greater ischial tenderloin ( incisura ischiadica major ), located below the posterior superior iliac spine, and a small sciatic notch ku (incisura ischiadica minor).

Pubic, or pubic, bone forms the anterior wall of the pelvis, consists of the bodyand two branches - the upper ( ramus superior ossis pubis) and lower (ramus inferior ossis pubis ). The body of the pubis forms part of the acetabulum. Togetherconnection of the ilium with the pubis is the iliopubic elevation ( eminentia iliopubica).

The upper and lower branches of the pubic bones are connected to each other in frontthrough cartilage, forming a sedentary joint, a half-joint ( symphysis ossis pubis ). The slot-like cavity in this connection is filled with liquid andincreases during pregnancy. The lower branches of the pubic bones formyut angle - pubic arch. Along the posterior edge of the superior ramus of the pubisthe pubic ridge stretches ( crista pubica ), passing backwards into linea arcuata of the ilium.

Sacrum(os sacrum ) consists of 5-6 vertebrae fixed to each other, the size of which decreases downwards. The sacrum has the shape of acone. The base of the sacrum is turned upward, the apex of the sacrum (narrowpart) - downwards. The anterior surface of the sacrum has a concave shape; on itthe junctions of the fused sacral vertebrae are visible in the form of transverserough lines. The posterior surface of the sacrum is convex. Along the midlinepass the spinous processes of the sacral vertebrae fused together.First sacral vertebra connected to V lumbar, has a protrusion - sacral cape (promontorium).

Coccyx (os coccygis ) consists of 4-5 fused vertebrae. He connectsusing the sacrococcygeal articulation with the sacrum. In braid connections the pelvis has cartilaginous layers.

The female pelvis from an obstetric point of view

There are two parts of the pelvis: the large pelvis and the small pelvis. border between them is the plane of entry into the small pelvis.

The large pelvis is bounded laterally by the wings of the ilium, behind -last lumbar vertebra. In front, it has no bony walls.

The pelvis is of the greatest importance in obstetrics. Through the small pelvisthe birth of the fetus is going on. There is no easy way to measure the pelvis.At the same time, the dimensions of the large pelvis are easy to determine, and based on them you can judge the shape and size of the small pelvis.

The small pelvis is the bony part of the birth canal. Form andthe size of the small pelvis is very important during childbirth and the definition of tactics for their management. With sharp degrees of narrowing of the pelvis and its deformationyah, childbirth through the natural birth canal becomes impossible, and women well, delivery by caesarean section.

The posterior wall of the small pelvis is made up of the sacrum and coccyx, the lateral ones arefarther bones, anterior - pubic bones with l circumferential symphysis. Top-The lower part of the pelvis is a solid bone ring. In the middle andlower thirds of the wall mscarlet pelvis is not continuous. In the lateral sections there are large and small sciatic foramen ( foramen ischiadicum majus etminus), limited respectively by large and small ischial notches (incisure ischiadica major et minor) and withviscous ( lig. sacrotuberale, lig. sacrospinale ). The branches of the pubic and ischial bones, merging, surroundobturator opening ( foramen obturatorium ) shaped like a triangle with rounded corners.

In the small pelvis, an entrance, a cavity and an exit are distinguished. In the pelvic cavity, excretelyayut wide and narrow parts. In accordance withthis in the pelvis distinguish four classical planes ( rice. one ).

The plane of the entrance to the small pelvis anteriorly bounded by the superior margin of the symphysis andthe upper inner edge of the pubic bones, from the sides - arcuate linesiliac bones and behind - sacral promontory. This plane is shapedtransversely located oval (or kidney-shaped). It distinguishes three size (rice. 2): straight, transverse and 2 oblique (right and left). Straight size is the distance from the upper inner edge of the symphysisto the sacral cape. This size is called the true or obstetric conjugates (conjugata vera) and equal 11 cm.

In the plane of the entrance to the small pelvis, tea still anatomical conjugate (conjugata anato - mica ) - the distance betweenthe upper edge of the symphysis andsacral cape.The value of the anatomical conjugate is11.5 cm. P about the pepper size - the distance between the most distant parts of the du-curved lines. He co-sets 13.0-13.5 cm. plane dimensions entrance to the small pelvisrepresent the distance betweendu sacroiliacarticulation of one sideny and the iliac-pubic eminence of the oppositefalse side. Rightthe oblique dimension is determinedfrom the right sacro-under-iliac joint, le-exit - from the left. These sizes Rs range from 12.0 to 12.5 cm .

The plane of the wide gas-ti cavity of the small pelvis from the front it is limited by the middle of the inner surface of the symphysis, from the sides - by the middle of the plates covering the acetabular cavities, from behind - by the junction of the II and III sacral vertebrae. In the wide part of the bands of the small pelvis, there are

2 sizes: straight and transverse. Straight size— distance between the junction of AND and III sacral vertebrae and the middle of the inner surface of the symphysis. It is equal to 12.5 cm. The transverse size is the distance between the midpoints of the inner surfaces of the plates covering the acetabulum. It is equal to 12.5 cm. Since the pelvis in the wide part of the cavity does not represent a continuous bone ring, oblique dimensions in this section are allowed only conditionally (13 cm each).

The plane of the narrow gasti of the pelvic cavity bounded in front by the lower edge of the symphysis, laterally by the awns of the ischial bones, and behind by the sacrococcygeal articulation.

In this plane, 2 sizes are also distinguished. Direct size - distance gap between bottom edgesymphysis and sacrococcygealjoint. He is equal 11.5cm. Cross dimension - the distance between thetyami ischial bones. He is 10.5 cm.

Plane of exit from the small pelvis( rice. 3 ) is limited in front by the lower edge of the pubic symphysis, from the sides - by the ischial tubercles, from behind - by the tip of the coccyx. Direct size - dis- standing between the bottom edgesymphysis and apex of the cop-chica. It is equal to 9.5 cm.the passage of the fetus through the birth canal (through the plane of exit from the small pelvis)due to protrusion of the coccyxposteriorly, this size is increasedshrinks by 1.5-2.0 cm and becomesnew equal to 11.0-11.5 cm. Cross dimension - the distance between the internal surfaces of the gray- personal bumps. It is equal to 11.0 cm.

When comparing the dimensions of the small pelvis in different planes, it turns out that in the plane of the entrance to the small pelvis, the transverse dimensions are maximum, in the wide part of the cavity of the small pelvis, the direct and transverse dimensions are equal, and in the narrow part of the cavity and in the plane of exit from the small pelvis, the direct dimensions are larger than the transverse ones.


In obstetrics, in some cases, a system is used parallel Goji planes( rice. four ). The first, or upper, plane (terminal) passes through the upper edge of the symphysis and the border (terminal) line. The second parallel plane is called the main one and passes through the lower edge of the symphysis parallel to the first. The fetal head, having passed through this plane, does not encounter significant obstacles in the future, since it has passed a solid bone ring. The third parallel plane is the spinal plane. It runs parallel to the previous two through the ischial spines. The fourth plane - the exit plane - runs parallel to the previous three through the top of the coccyx.

All classical planes of the small pelvis converge in the direction of the anterior (symphysis) and fan-shaped diverge backwards. If you connect the midpoints of all the direct dimensions of the small pelvis, you get a line curved in the form of a fishhook, which is called wire axis of the pelvis. It bends in the cavity of the small pelvis, corresponding to the concavity of the inner surface of the sacrum. The movement of the fetus through the birth canal occurs in the direction of the wire axis of the pelvis.

Angle of inclination of the pelvis - this is the angle formed by the plane of entry into the small pelvis and the horizon line. The value of the angle of inclination of the pelvis changes when the center of gravity of the body moves. In non-pregnant women, the angle of inclination of the pelvis is on average 45-46 °, and the lumbar lordosis is 4.6 cm (according to Sh. Ya. Mikeladze).

As pregnancy progresses, lumbar lordosis increases due to the displacement of the center of gravity from the region of the II sacral vertebra anteriorly, which leads to an increase in the angle of inclination of the pelvis. With a decrease in the lumbar lord dose, the angle of inclination of the pelvis decreases. Up to 16-20 weeks. pregnancy in the setting of the body, no changes are observed, and the angle of inclination of the pelvis does not change. By the gestational age of 32-34 weeks. lumbar lordosis reaches (according to I. I. Yakovlev) 6 cm, and
the angle of inclination of the pelvis increases by 3-4°, amounting to 48-50° ( rice. 5 ). The magnitude of the angle of inclination of the pelvis can be determined using special devices designed by Sh. Ya. Mikeladze, A. E. Mandelstam, as well as manually. When a woman is positioned on her back on a hard couch, the doctor holds her hand (palm) under the lumbosacral lordosis. If the hand passes freely, then the angle of inclination is large. If the hand does not pass, the angle of inclination of the pelvis is small. It is possible to judge the magnitude of the angle of inclination of the pelvis by the ratio of the external genitalia and thighs. With a large angle of inclination of the pelvis, the external genital organs and the genital gap are hidden between the closed thighs. With a small angle of inclination of the pelvis, the external genital organs are not covered by closed hips.

You can determine the value of the angle of inclination of the pelvis by the position of both iliac spines relative to the pubic joint. The angle of inclination of the pelvis will be normal (45-50°) if, in the horizontal position of the woman's body, the plane drawn through the symphysis and the superior anterior iliac spines is parallel to the plane of the horizon. If the symphysis is located below the plane drawn through these spines, the angle of inclination of the pelvis is less than normal.

A small angle of inclination of the pelvis does not prevent the fixation of the fetal head in the plane of the entrance to the small pelvis and the advancement of the fetus. Childbirth proceeds quickly, without damage to the soft tissues of the vagina and perineum. A large angle of inclination of the pelvis often presents an obstacle to fixing the head. Incorrect insertion of the head may occur. In childbirth, injuries of the soft birth canal are often observed. By changing the position of the body of a woman in labor during childbirth, it is possible to change the angle of inclination of the pelvis, creating the most favorable conditions for the advancement of the fetus through the birth canal, which is especially important if a woman has a narrowing of the pelvis.

The angle of inclination of the pelvis can be reduced by raising the upper body of the lying woman, or in the position of the body of the woman in labor on her back, bring the legs bent at the knee and hip joints to the stomach, or put a polster under the sacrum. If the polster is under the lower back, the angle of inclination of the pelvis increases.

Loading...Loading...