Large and small pelvis structure. Hip bone

The joints of the human lower extremities include articulations various bones, which provide mobility and enable movement in space. This material presents the anatomy of the joints of the lower extremities, which includes basic information about the ligaments, the structure of the human pelvis, and the bones included in the cavity of a particular joint.

The girdle of the lower extremities is represented by the articulations of the pelvic bones with each other in their anterior section and with the sacrum in the back. The joints of the pelvic girdle include the pubic symphysis and the paired sacroiliac joint. The sacrum, wedged between the two pelvic bones, is the “key” of the pelvic ring.

Pubic symphysis

The pubic symphysis is formed by the symphysial surfaces of the pubic bones that articulate with each other. In this place between them there is a cartilaginous interpubic disc with a narrow slit-like cavity located in the sagittal plane. The pubic symphysis is strengthened by two ligaments. The superior pubic ligament is a bundle of transversely oriented connective tissue fibers connecting the pubic bones. The inferior pubic ligament is adjacent to the pubic symphysis from below, occupying the apex of the subpubic angle.

The sacroiliac joint is formed by several bones

The sacroiliac joint is formed by the ear-shaped surfaces of the pelvic bone and the sacrum. The strong capsule of this joint is supported by powerful anterior and posterior sacroiliac ligaments. There are also interosseous sacroiliac ligaments on the posterior side of the joint.

The joint is also strengthened by the iliopsoas ligament, stretched between the transverse processes of the two lower lumbar vertebrae and the iliac crest. Outside the sacroiliac joint are two powerful ligaments stretched between the sacrum and the pelvic bone. These are the sacrotuberous and sacrospinous ligaments, closing the sciatic notches of the pelvic bone and turning them into the greater and lesser sciatic foramina. These ligaments deepen the pelvic cavity.

The structure of the human pelvic bones: female and male types

The pelvic bones and sacrum are connected to form the pelvis. The structure of the pelvic bones is a bone ring, inside of which is the pelvic cavity. The anterior wall of the pelvis is short - this is the pubic symphysis, formed by the symphysial surfaces of the pubic bones facing each other, which are covered with cartilage and connected to each other by the interpubic disc, in which there is a gap. Back wall The pelvis is long, formed by the sacrum and coccyx, the side walls are formed by the internal surfaces of the pelvic bones and ligaments (sacrotuberous and sacrospinous). The obturator foramen located on the side wall is closed by a membrane of the same name. This general structure human pelvis, which can be divided into male and female type depending on the gender of the person.

The border line, formed by the arcuate lines (right and left) of the iliac bones and the ridges of the pubic bones, behind - the promontory of the sacrum, in front - the upper edge of the pubic symphysis, divides the pelvis into 2 sections: large and small. Big pelvis formed by the wings of the ilium and the body of V lumbar vertebra. The small pelvis is limited by the branches of the pubic and ischial bones, the ischial tuberosities, the sacrotuberous ligaments, the sacrum and the coccyx. The sacroiliac joint is formed by the sacrum and ilium that are part of it.

The structure of the pelvis of a woman and a man

Structure female pelvis wider and lower, and all its dimensions are larger than those of men. The bones of the female pelvis are thinner than those of the male. The sacrum in men is narrower and concave, the promontory protrudes forward. The structure of the pelvis in women differs in that the sacrum is wider and more flattened, and the promontory is less pronounced than in men. The angle at which the lower branches of the pubic bones connect (subpubic angle) is acute in men: about 70-75°, in women it approaches straight and even obtuse - 90-100°. The ischial tuberosities and wings of the ilium are located further apart in women than in men. Thus, the distance between both upper anterior iliac spines in women is 25-27 cm, in men - 22-23 cm. The lower aperture (hole) of the female pelvis is wider than the male one, it has the shape of a transverse oval (the structure of the male pelvis has the shape of a longitudinal oval ), and the pelvic volume is larger than in men. The pelvic tilt (the angle between the plane of the boundary line and the horizontal) is also greater in women (55-60°) than in men (50-55°).

The straight diameter of the upper aperture is the distance between the promontory and the upper edge of the symphysis, the lower aperture is the distance between the apex of the coccyx and the lower edge of such an important joint as the pubic symphysis. The transverse diameter of the upper aperture is the distance between the most distant points of the boundary line, the diameter of the lower aperture is the distance between the inner edges of the ischial tuberosities. The oblique diameter of the superior aperture is the distance between the sacroiliac joint on one side and the iliopubic eminence on the other. So, gender differences in the structure of the female pelvis come down mainly to its larger size and volume, and an increase in the lower aperture compared to the male pelvis. This is due to the function performed: the pelvis is the container for the fetus developing in the uterus, which during childbirth leaves the pelvic cavity through the lower aperture.

The structure of the hip joint and its photo

Structure hip joint and the free part of the lower limb has features associated with their functions: participation in movement in space, maintaining body balance and vertical position of a person.

The hip joint, and this is clearly visible in the photo, is spherical, multi-axial, formed by the acetabulum of the pelvic bone and the head femur. The depth of the acetabulum is increased by the cartilaginous acetabular lip, which is firmly fused to the edge of the acetabulum.

Head, nerve and ligaments of the hip joint

The hip joint capsule is very strong. Its strength is significantly increased due to the work of tissues such as the ligaments of the hip joint. The most powerful is the iliofemoral ligament, its thickness is about 1 cm. The ligament begins slightly below the anterior inferior iliac spine and attaches, fanning out, to the intertrochanteric line. The pubofemoral and ischiofemoral ligaments are much weaker than the iliofemoral ligament. If a person is standing, all three ligaments are tense. Inside the cavity of the hip joint is the ligament of the head of the femur, which plays an important role during the formation of the hip joint, holding the head of the femur to the acetabulum. The head of the femur is surrounded by a ligament that serves as a shock absorber that softens the shock experienced by the hip joint during movement. The nerve of the hip joint passes here, which innervates the lower limb.

Bones and nucleus of the hip joint

The nucleus of the hip joint is a synovial bursa formed by the acetabulum and the femoral bones included in it. All bones of the hip joint are reliably protected from damage due to friction by the synovial bursae. Due to the large depth of the acetabulum, the hip joint is a type of spherical joint - a cup-shaped joint. It has 3 axes of rotation: transverse, sagittal and vertical (longitudinal). According to these axes, the hip can perform flexion (forward movement) and extension (backward movement), abduction and adduction, rotation inward (pronation) and outward (supination), as well as circular movement (circumduction).

Hip angles

There are certain angles of the hip joints within which mobility can occur within physiological norm. The mobility of the femur in the hip joint in a living person during flexion and extension reaches 120°; of which 105° is in flexion and 15° is in extension. Limited hip extension is associated with tension in the iliofemoral ligament. Around vertical axis In the hip joint, the head of the femur rotates inward and outward. The total volume of rotation is 40-50°. Due to movements around the sagittal axis in the hip joint, abduction and adduction of the lower limb occur in relation to midline(up to 80-90°).

Structure of the knee joint

The structure of the knee joint is complex; it is a condylar, trochlear-rotational apparatus. This is the largest and most complex human joint in its structure. Three bones take part in its formation: the femur, tibia and patella. When flexing and extending the lower leg, it works as a trochlear joint. As the tibia bends, due to a decrease in the radius of curvature of the articular surface of the femoral condyles and relaxation of the ligaments, movements similar to rotational movements in a ball-and-socket joint (slight rotation of the tibia inward and outward) can occur in it. Articular surfaces tibia and the femurs are supplemented with intra-articular cartilages - medial and lateral menisci, which increase the correspondence (congruence) of the articulating surfaces.

Medial and internal meniscus of the knee joint and its photo

Each meniscus is a semilunar-shaped fibrocartilaginous plate, the thick edge of which faces outward and is fused with the joint capsule, and the thinned edge is directed medially. The upper surface of the menisci is concave and corresponds to the surface of the condyles of the femur, and the lower surface is almost flat, adjacent to the upper articular surface of the tibia.

The medial meniscus of the knee joint articulates superiorly with the medial condyle, inferiorly with the medial part of the superior articular surface of the tibia, internal meniscus knee joint - respectively with the lateral condyle and the lateral part of the upper articular surface of the tibia. Anteriorly, the menisci are connected to each other by the transverse knee ligament. Look at the meniscus of the knee joint in the photo on this page:

Cruciate ligaments of the knee joint

The knee joint capsule is thin, loose and very extensive. From the side of the joint cavity, it fuses with the outer edges of both menisci. The synovial membrane of the capsule forms numerous folds. The paired pterygoid folds are the most developed. There is a a large number of synovial bursae (patellar, deep infrapatellar, popliteal recess, etc.). The knee joint is reinforced by intra-articular (anterior and posterior cruciate ligaments knee joint) and extra-articular ligaments (fibular and tibial collateral ligaments, oblique and arcuate popliteal ligaments, patellar ligament).

IN knee joint Movements around two axes are possible: transverse and vertical. Flexion and extension occur around the transverse axis with a total range of motion of 140-150°. Due to relaxation collateral ligaments When bending the knee joint, rotation around the vertical (longitudinal) axis is possible. The total volume of active rotation in the knee joint is on average 15°, passive - 30-35°.

Tibiofibular joint

The interfibular joint is the articulation of the flat articular surfaces of the head of the fibula with the fibular articular surface of the tibia. Along their edge is attached a tightly stretched articular capsule, reinforced by the anterior and posterior ligaments head of the fibula. The interfibular syndesmosis is a continuous connection formed by the fibular notch of the distal epiphysis of the tibia and the articular surface of the lateral malleolus. The synovial membrane is often invaginated into the syndesmosis. ankle joint, then it becomes the lower tibiofibular joint. The interosseous membrane of the leg is stretched between both bones of the leg. At the top and lower parts membranes have openings for the passage of blood vessels and nerves.

Anatomy of the structure of the human foot and toes and its photo

The structure of the human foot is such that its bones articulate with the bones of the lower leg and with each other, forming joints that are complex in structure and function, which can be divided into five groups:

• articulations of the bones of the foot with the bones of the lower leg;
• articulations of the tarsal bones with each other;
• articulations between the bones of the tarsus and metatarsus;
• articulations of the metatarsal bones with the proximal phalanges;
• articulation of the phalanges of the fingers with each other.

The anatomy of the foot and structure imply high motor activity. The second important factor that affects the structure of the foot and toes is high physical activity. The entire leg and foot structure are designed to allow a person to move freely in space. You can see the structure of the foot in the photos, which show different projections of this part of the lower limb.

Structure, bones and ligaments of the ankle joint of the foot

The ankle joint is block-shaped, complex, uniaxial, formed by the articular surfaces of both tibia bones and the talus. The tibia and fibula bones of the ankle joint, connected together like a fork, cover the block of the talus - this is the structure of the ankle joint. In this joint, around a transverse axis passing through the block of the talus, flexion (movement towards the plantar surface of the foot) and extension (movement towards its dorsal surface) are possible. The total volume of these movements is 60-70°. Due to the fact that the block is slightly wider in front than in the back, when the foot is flexed, slight adduction and abduction become possible. The foot and ankle joint are strengthened by ligaments located on the lateral surfaces of the joint. The medial collateral (deltoid) ligament has the shape of a wide fibrous plate diverging downwards. On the lateral side, the capsule is strengthened by three ligaments of the ankle joint: the anterior talofibular, posterior talofibular and calcaneofibular.

Joints of the human foot and their photos

The joints of the human foot are represented by the following joints: subtalar, talocaleonavicular, calcaneocuboid, transverse tarsal joint, tarsometatarsal, all of them are strengthened by ligaments. For clarity and understanding, we suggest you look at photos of the foot joints

The subtalar joint is cylindrical, uniaxial, formed by the talus and calcaneus. The articular surfaces, completely congruent in shape and size, have a cylindrical shape. This joint is strengthened by the strong interosseous talocalcaneal ligament and the medial and lateral talocalcaneal ligaments. Small movements around the sagittal axis are possible in the joint.

The talocaleonavicular joint is formed by the head of the talus, calcaneus and navicular bones. It is strengthened by the talonavicular dorsal ligament and the calcaneonavicular plantar ligament. Based on the shape of the articular surfaces, this joint can be classified as spherical, but movement in it is only possible around the sagittal axis together with movements in the subtalar joint, i.e. both joints function together as a combination joint. Pronation and supination of the foot occur around the sagittal axis. When pronating with the bones of the lower leg and with each other, forming, during supination the reverse movement occurs. The ankle, subtalar and talocalcaneal-navicular joints, complementing each other in terms of mobility, allow the foot to produce the following movements: flexion and extension, adduction and abduction, pronation and supination, and circular movement.

The transverse tarsal joint (Chopard joint) is formed by two joints: the calcaneocuboid and the talonavicular. The talonavicular joint is ball-and-socket, formed by the articular surfaces of the head of the talus and the scaphoid. The calcaneocuboid joint is formed by the calcaneus and cuboid bones. The articular surfaces are highly congruent. The shape of the joint is saddle-shaped. On the plantar side, the capsule of this joint is strengthened by ligaments, of which the most powerful are the long plantar ligament and the plantar calcaneocuboid ligament. The transverse joint has a strong common bifurcated ligament that begins on the dorsum calcaneus, and is attached with one part on the scaphoid bone, the other on the cuboid. Mobility in this joint is low.

The sphenolvicular joint, flat in shape, connects three sphenoid bones with the scaphoid bone.

The joints of the tarsal bones are strengthened by dorsal and plantar ligaments and interosseous ligaments. A special role is played by the extremely strong short intra-articular interosseous talocalcaneal ligament. The longest plantar ligament has the greatest strength, which spreads between the lower surface of the heel bone and the bases II - V metatarsal bones.

The tarsometatarsal joints are formed by the articulations of the cuboid and sphenoid bones with the bones of the metatarsus. These are three isolated joints. All of them are flat, with the exception of the first (between the medial cuneiform and first metatarsal bones), which can sometimes be saddle-shaped in shape. The joint capsules are strengthened by the dorsal and plantar tarsometatarsal ligaments. Mobility in the joints is minimal.

Interphalangeal and metatarsophalangeal joints of the foot

The metatarsophalangeal joints of the foot are formed by the heads of the metatarsal bones and the bases of the proximal phalanges of the toes. These joints are spherical, however, the mobility in them is relatively low. The joints are strengthened by collateral and plantar ligaments, as well as the deep transverse metatarsal ligament. The joints are capable of flexion and extension, as well as slight abduction and adduction.

The interphalangeal joints of the foot are classified as trochlear joints in shape, which are strengthened on the sides by collateral ligaments.

Anatomy and structure of the foot

The human foot performs a strictly specialized function of movement and support. This is due to its structure, which resembles a strong and elastic vaulted arch with short fingers. The main features of the human foot, in addition to the arches, are a pronated position, strengthening of the medial edge, shortening of the toes, strengthening and adduction of the first toe, which is not opposed to the rest, and expansion of its distal phalanx. The seven stress-bearing tarsal bones are massive and very strong. They are arranged in two rows. In the proximal (posterior) row there are the talus and calcaneus, in the distal (anterior) row there is the cuboid bone laterally, medially there is the narrow scaphoid, and in front of it there are three wedge-shaped bones. The bones of the medial edge of the tarsus lie higher than the bones of the lateral edge, due to this the arch of the foot is formed.

In humans arched foot, it is represented by five longitudinal arches and one transverse arch (arcs), which are convexly facing upward. The arches are formed by the bones of the tarsus and metatarsus that articulate with each other. Each longitudinal arch starts from the same point of the calcaneus - the calcaneal tuberosity and includes the bones of the tarsus and the corresponding metatarsal bone. The support of the talus also participates in the formation of the first arch - the medial one. The foot as a whole has 3 points of support: the calcaneal tubercle and the heads of the 1st and 5th metatarsal bones. The height of the longitudinal arches varies. The highest vault II (second arch). As a result of the unevenness of the longitudinal arches, a transverse arch of the foot is formed. The arched structure of the foot in a living person is maintained by the shape of the bones, the strength of the ligaments (passive “tightening” of the foot) and the tone of the muscles (active “tightening” of the foot). To strengthen the longitudinal arches of the foot, the most important are the long plantar ligament and the plantar calcaneonavicular ligament; for the transverse arch, the deep transverse metatarsal and interosseous metatarsal ligaments.

Depending on the condition of the arches, the foot may be normal, flattened or flat.

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The pelvic girdle bears the weight of the entire upper body, and they rest against it lower limbs. This part of the body experiences a lot of pressure from both sides - below and above, it promotes the movements of the lower limbs and protects important internal organs. The most important function of the pelvis is locomotor, facilitating movement of the body in space.

The differences between the human pelvis and the pelvis of other mammals are related to
with a vertical body position. Only humans have transverse dimensions
The pelvis is larger than the straight ones (antero-posterior). Even the pelvis of great apes
narrower and more elongated in length. In a human fetus, the pelvis has the same shape as
the same as the pelvis of four-legged mammals. Pelvic transformations begin
under the influence of mechanical loads: the weight of the torso, pressure in the hip
joint during movements, etc. Active formation of sexual differences
in the structure of the pelvis occurs during puberty under the influence
hormones. It is characteristic that with reduced ovarian function (female
gonads) slows down the formation of female
features - the pelvis remains relatively narrow.

Pelvic bones

The pelvic girdle, or pelvis, is a strong bony ring that is located in the lower part of the human torso skeleton. It is formed from almost motionlessly connected bones: the unpaired one - the sacrum and two massive, flat ones - the right and left pelvic bones. Wedged between the pelvic bones is the sacrum, to which is attached a small bone - the coccyx - a rudimentary remnant of the caudal skeleton.

In children under 16 years of age, each pelvic bone consists of 3 separate bones: the ilium, the ischium and the pubis, connected to each other by layers of cartilaginous tissue. After 16 years they grow together. At this place there is a deep fossa - the acetabulum. The head of the femur enters it, forming the hip joint.

The structure of the ischium
The ischium has a powerful ischial tuberosity, on which the human body rests when sitting. If a person is standing, the ischial tuberosity is hidden by a thick layer gluteal muscles and fatty tissue.

Structure of the pubic bone
The pubic bone has 2 branches connected to each other at an angle. These branches, together with the branch of the ischium, limit the large obturator foramen on the pelvic bone, covered with a dense membrane. The pubic bones on the right and left are connected to each other through cartilage - thus forming the pubic symphysis (half-joint), one of the joints of the pelvic girdle. The elevation of the skin above the symphysis is called the pubis.

The importance of the pubic symphysis is especially great for female body. By the time of birth, the cartilaginous layer between pubic bones softens, and the gap inside it allows the bones to move apart and thereby somewhat expand the birth canal.

Structure of the ilium
The ilium consists of a body and a thin wing, which expands upward and ends in a long crest. The ridge serves as the attachment point for the broad abdominal muscles. The depression on the inner surface of the wing forms the iliac fossa. It is in this fossa on the right that the cecum is located with vermiform appendix(appendix).

Posteriorly on the ilium there is articular surface, shaped like auricle. It is tightly connected to exactly the same surface on the sacrum, forming a flat sacroiliac joint. This joint is strengthened on all sides by bundles of ligaments, which in terms of their strength are considered the most powerful in the human body.

Angle of inclination of the pelvic bones
The pelvic bones are the attachment point for the muscles of the abdomen, back and lower extremities. IN vertical position The human pelvis is tilted forward at an angle of 45-60 degrees relative to the horizontal plane. The size of the angle depends on posture; in women it is larger than in men.

Large and small pelvis

There are large and small pelvises. The boundary line dividing them runs along the inner surface of the pelvic bones from the protrusion on the spine - the promontory (the junction of the last lumbar vertebra with the sacrum) to the upper edge of the pubic symphysis.

Big pelvis
The pelvis major is the upper section of the pelvis, formed by the unfolded wings of the ilium. It is the bottom wall abdominal cavity and serves as a support for internal organs.

Small pelvis
The small pelvis is located below the large pelvis and is limited from behind by the sacrum and coccyx, in front and from the sides by the ischial and pubic bones. It distinguishes between entrance, exit and cavity. In the pelvic cavity there are bladder, rectum and internal genital organs (ovaries, the fallopian tubes, uterus and vagina, prostate, seminal vesicles and vas deferens). The entrance to the small pelvis is open to the abdominal cavity and corresponds to the border line with the large pelvis. The exit from the pelvic cavity is closed by the muscles that form the pelvic diaphragm; in men they pass through urethra and rectum, in women - the urethra, rectum and vagina. From the outside, this area of ​​the body stands out as the perineum.

The pelvic organs differ from the abdominal organs in that they can
significantly change its volume: periodically filled
and the bladder and rectum are emptied, and the
and the uterus moves during pregnancy. It affects
on the functioning of other organs and blood supply.

Female and male pelvis

In no part of the skeleton are sex differences more pronounced than in the pelvis. Sex differences in the pelvis begin to appear in children aged 8-10 years. The average size of the male pelvis is approximately 2 cm smaller than the average size of the female pelvis. The female pelvis is wider and shorter than the male, the wings of the ilium are more deployed. The angle between the lower branches of the pubic bones is rounded in the form of a pubic arch, the promontory almost does not protrude into the pelvic cavity, and thanks to the wide, short and flat sacrum, the pelvic cavity has the shape of a cylinder.

The structure of the pelvis in men
In men, the pelvis is narrower and higher: the wings of the ilium are located almost vertically, the sacrum is strongly concave, and the promontory clearly protrudes into the pelvic cavity, the subpubic angle is acute. As a result, both the entrance and exit from the male pelvis are greatly narrowed, and its cavity itself has a conical shape.

The structure of the pelvis in women
The fetus moves through the small pelvis in women during childbirth, so its shape and size vary great importance for normal birth. The dimensions of the small pelvis are determined by indirect measurements of the large pelvis with obstetric calipers. Inner dimensions determined by vaginal examination and ultrasound.

For example, the distance between the protruding tubercles on the iliac crest (the so-called superior anterior iliac spines) in women is normally 25-27 cm, and the distance between the most distant points of the crest on the right and left is 28-30 cm. The dimensions of the inlet and exit from the small pelvis, which are both direct and transverse dimension in women are about 11-13 cm. The direct size of the outlet from the small pelvis (the distance between the lower edge of the pubic symphysis and the apex of the coccyx), equal to 10 cm, during childbirth increases by 1.5-2 cm due to the posterior deviation of the apex of the coccyx.

In case of disturbances in the development of a girl, due to rickets, spondylitis, coxitis and other diseases and poor nutrition, neglect of classes physical culture or too big physical activity deviations are possible normal development pelvis - narrow pelvis. With a small degree of narrowing, childbirth is possible, but it can be long and difficult. With greater narrowing, obstacles arise for the passage of the fetus through the birth canal.

The large pelvis is much wider than the small pelvis, it is limited on the sides by the wings of the ilium, behind by the last lumbar vertebrae, and in front by the lower section 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 quite accurately. The size of the large pelvis is used to judge the size of the small pelvis, which cannot be directly measured. Meanwhile, determining the size of the small pelvis has important, since the born fetus passes through the stubborn bony canal of the small pelvis.

Small pelvis

Planes and dimensions of the small pelvis. The pelvis is the bony part of the birth canal. The posterior wall of the pelvis consists of the sacrum and coccyx, the lateral ones are formed by the ischial bones, and the anterior wall is formed by the pubic bones and the symphysis. The posterior wall of the pelvis is 3 times longer than the anterior one. Upper section The pelvis is a continuous, inflexible ring of bone. In the lower section, the walls of the small pelvis are not solid; they contain obturator foramina and sciatic notches, bounded by two pairs of ligaments (sacrospinous and sacrotuberous).

In the small pelvis there are the following sections: inlet, cavity and outlet. In the pelvic cavity there are wide And narrow Part. 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 pelvic cavity, III - the plane of the narrow part of the pelvic cavity, IV - the plane of the exit of the pelvis.

/. Plane of entry into the pelvis has the following boundaries: in front - the upper edge of the symphysis and the upper inner edge of the pubic bones, on the sides - innominate lines, in the back - 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 there are three sizes: straight, transverse and two oblique.

- Straight size - the distance from the sacral promontory to the most prominent point on the inner surface of the symphysis pubis. This size is called the obstetric, or true, conjugate (conjugata vera). There is also an anatomical conjugate - the distance from the promontory 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 equal to 1 1 cm.

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

Oblique sizes two: right and left, which are equal to 12-12.5 cm. Right oblique size - distance from the right sacroiliac joint to the left iliopubic tubercle, left oblique size- from the left sacroiliac joint to the right iliopubic tubercle. In order to more easily navigate in the direction of the oblique dimensions of the pelvis in a woman in labor, M.S. Malinovsky and M.G. Kushnir suggests the following technique. The hands of both hands are folded at right angles, with the palms facing upward; 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 - 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, in the back - 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 the II and III sacral vertebrae to the middle of the inner surface of the symphysis; equals 12.5 cm.

- Transverse size - between the tips of the acetabulum; equals 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 widest part of the pelvis are conditionally allowed (length 13 cm).

///. The plane of the narrow part of the pelvic cavity bounded in front by the lower edge of the symphysis, on the sides by the spines of the ischial bones, and behind by the sacrococcygeal joint. 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); equals 11-11,5 cm.

- Transverse size connects the spines of the ischial bones; equal to 10.5 cm.

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

- Straight pelvic outlet size goes from the top of the coccyx to the lower edge of the symphysis; it is equal to 9.5 cm. As the fetus passes through the small pelvis, the tailbone moves away by 1.5-2 cm and the direct size increases to 1 1.5 cm.

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

In addition to the above (classical) pelvic cavities, there are parallel planes of the pelvis (planes Goji).

The first (upper) plane passes through the terminal line (I. terminalis innominata) and is therefore called terminal plane.

Second - main plane, runs parallel to the first at the level of the lower edge of the symphysis. It is called the main one because the head, having passed this plane, does not encounter significant obstacles, since it has passed a solid bone ring.

Third - spinal plane, parallel to the first and second, crosses the pelvis in the spina oss area. ischii.

Fourth - exit plane, represents the bottom of the pelvis (its diaphragm) and almost coincides with the direction of the coccyx.

Wired axis (line) of the pelvis. All planes (classical) of the pelvis border in front with one or another point of the symphysis, and in the back - with different points of the sacrum or coccyx. The symphysis is much shorter than the sacrum and coccyx, so the planes of the pelvis converge anteriorly and fan out posteriorly. If you connect the middle of the straight dimensions of all the planes of the pelvis, you will get not a straight line, but a concave anterior (towards the symphysis) line. This conventional line connecting the centers of all direct dimensions of the pelvis is called wire axis of the pelvis. The wire axis of the pelvis is initially straight; it bends in the pelvic cavity according to the concavity of the inner surface of the sacrum. In the direction of the wire axis of the pelvis, the born fetus passes through the birth canal.

Pelvic angle(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°. It can be reduced by forcing a woman lying on her back to strongly pull her thighs towards her stomach, which leads to elevation of the womb. It can be increased by placing a roll-shaped hard pillow under the lower back, which will lead to a 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.

Serves as a support for the body.

There are large and small pelvises. The large pelvis is limited: in front soft tissues the anterior abdominal wall, behind -, from the sides - by the wings of the iliac bones; small pelvis: in front - by the pubic (pubic) bones, in the back - by the sacrum and coccyx, and on the sides - by the ischial bones.

The pelvic bone consists of three bones: the ilium, the ischium and the pubis, connected to the lateral sections of the sacrum (sacroiliac joint) and to each other (pubic joint). The lower part of the sacrum is connected to the coccyx, forming a low-moving joint, strengthened in front and behind by ligaments. On the posterior surface of the ischium there are two notches that overlap with ligaments, forming the greater and lesser sciatic foramen. The musculoskeletal formations present in the pelvis: the anterior superior and inferior spines, the iliac crest, the pubic joint, etc. serve as identification points used for orientation in this area and measurement of the pelvis. There is some flattening of the ilium, a discrepancy in size and shape of the acetabulum and the femoral head.

Sexual characteristics of the pelvis - see.

The pelvis contains the organs lower section abdominal cavity (small and large intestine); pelvis - bladder, rectum and internal (in women - the uterus and its appendages, in men - part of the vas deferens).

The peritoneum, covering the pelvic organs, forms pouches during the transition from one organ to another: in men, vesico-rectal, in women, vesico-uterine and rectal-uterine, which in case of pathology can be filled with blood. In the subperitoneal space (between the peritoneum and fascia) lies fiber that envelops the vessels, nerves and pelvic organs.

Within the pelvis are located: iliopsoas, internal obturator, piriformis muscles, which originate from the pelvic bones and are attached to the thigh; levator muscle anus, anal sphincter and coccygeus muscle. The external pelvic muscle group includes: the external obturator, gluteus maximus, gluteus medius and minimus, and the superior and inferior gemellus muscles. The levator ani muscle is woven with its fibers into the walls of the vagina and rectum and is attached to the tailbone.

In the area of ​​the obturator foramen and membrane, both internally and externally, the internal and external obturator muscles begin, which are attached to the thigh in the area of ​​the trochanteric fossa. Departs from the lateral surface of the II, III and IV sacral vertebrae and the sacroiliac joint piriformis muscle, passing through the greater sciatic foramen and attached to the apex of the greater trochanter. This muscle, passing through the indicated opening, forms two slits: supra- and infrapiriform; through the first of them the superior gluteal vessels and nerve emerge, and through the second (infrapiriform) - the inferior gluteal vessels and the nerve of the same name, sciatic nerve etc. Through the small sciatic foramen, the pudendal vessels and nerve penetrate from the pelvis.

The exit from the small pelvis is limited by the ischial tuberosities, sacrotuberous ligaments and is closed by the muscles (levator ani and coccygeus) and fascia that form pelvic floor, or the pelvic diaphragm. The angle between the pubic bones is formed by the urogenital diaphragm, formed by two muscles - the sphincter of the urethra and the deep transverse muscle crotch. The urethra and pass through the urogenital diaphragm, and through the pelvic diaphragm.

The anatomy of the human pelvis is quite complex. This is facilitated by high load and wide range functions performed. The human pelvis connects the torso and lower limbs; accordingly, pressure is exerted both from above and from below.

It is interesting that out of all the diversity of mammals on the planet, it is humans that have pelvic sizes of cross section more than in the anterior-posterior. Moreover, in intrauterine development The shape of the fetal pelvis is the same as that of four-legged mammals, but changes over time.

Due to the nature of gender differences and the characteristics of the body, the pelvic bone of women is wider and lower. Its wings and tubercles of the ischial region are more spread out to the sides to facilitate pregnancy and childbirth. Differences in the structure of the pelvis begin to form immediately after the onset of the first menstruation (under the influence of female sex hormones).

Interestingly, with a lack of female sex hormones, against the background of reduced ovarian function, the anatomy of the female pelvis changes (becomes narrow) due to a slowdown in the formation female characteristics.

What functions does the human pelvis perform?

IN anatomical structure human body the pelvis has great value, as it performs important functions for the body:

• supporting - the spinal column is attached to it;
• protective - human organs are located inside the pelvic cavity (bladder, colon, female and male genital organs);
• the pelvis functions as the center of mass of the human skeleton;
• hematopoietic - due to great content red bone marrow.

Protection

One of essential functions The pelvis is considered protective. Anatomy human body is such that almost all reproductive organs, the bladder and some abdominal organs are located in the pelvic area.

All these organs are protected from mechanical damage and displacement by bone tissues of the pelvic cavity.

This is especially important for women when carrying a child. The pelvic floor in the form of a junction of the sacrum and ilium is connected by ligaments and supports the uterus in the required position.

Pelvic bone structure

The pelvic bone is one of the most massive bone structures of the human body, and its structure and geometric shape are determined by its main function – support. It is formed by three sections: the ischial, pubic and iliac. Moreover, before the onset of puberty, the sections are separated by cartilage tissue, and at the age of 14-17 years the sections fuse and become one single pelvic bone.

The merging of departments occurs in areas with the heaviest loads- in the area of ​​the acetabulum. The head of the femur is located in the acetabulum and thus forms the hip joint.

The iliac pelvis is located above the acetabulum and consists of a wing and a body. The wing at the end has a kind of ridge to which they are attached. muscle fibers abdominal cavity. On the posterior side of the ilium, the surface of the bone is connected to the joint of the sacrum (sacroiliac joint).

The pubic region is located below the acetabulum in front. It consists of two branches connected at an angle. At the junction of the branches there is cartilage tissue. All together is pubic symphysis. During the restructuring of the female body for childbirth, the cartilage tissue softens and the bones move apart so as not to impede the baby’s exit from the birth canal.

The ischial region is located symmetrically to the pubis at the back. Like the pubis, it is located below the acetabulum. Bone tissue The ischial region has powerful tubercles that are covered with muscle and fatty tissue. It is the tubercles that support a person when he is in a sitting position.

The human pelvis is formed by the pelvic structures, the sacrum and the coccyx. Together they form a ring-shaped pelvic cavity.

Hip joint

One of the most important joints in humans that allows us to walk, run or move objects is the hip joint.

The formation of the joint begins in the womb. After birth, it partially consists of a cartilaginous hyaline layer, and at 4-5 months the cartilage ossifies. At the same time, intensive growth of the femur bones occurs. During the process of growing up, the hyaline cartilage completely ossifies and growth stops. In the following, the form mutual arrangement and the structure of human bones is constantly undergoing change.

The hip joints consist of two acetabulums of the pelvic bone and a pair of femoral heads. The shape of the joint corresponds to a spherical one, since the acetabulum has the appearance of a semi-spherical shape, which is filled with fatty tissue, and there is a cartilaginous rim along the edges. The structure of the hip joint is determined by the nature of the functions performed.

The ball-shaped head of the femur, covered with cartilage, is connected by the femoral neck to the bone itself (acetabulum). Outside surface The joint is covered by a durable capsule. There are several ligaments inside the joint. For example, the femoral head ligament absorbs stress on the femur bone during motor activity, and also protects the feeding vessels inside it.

The iliofemoral ligaments are the strongest in the entire human body, and their thickness is about 8-10 mm. Their function is to slow down the extension and internal rotation of the hip. The pubofemoral pair of ligaments, on the contrary, inhibits hip abduction in an extended position.