The pelvis is the bottom of the human body between the stomach and thigh (sometimes also called pelvic area from the torso) or the embedded frame (sometimes called pelvic bone , or pelvic bone ).
The pelvic area of ​​the torso includes the pelvis, the pelvic cavity (the space covered by the hip bone), the pelvic floor, under the pelvic cavity, and the perineum, below the pelvic floor. The pelvic skeleton is formed in the back area, by the sacrum and the tail bone and anteriorly and to the left and right, by a pair of hip bones.
Both pelvic bones connect the spine with the lower limbs. They attach to the posterior sacrum, connect to each other anteriorly, and join the two femures in the hip joint. The gap covered by the pelvis, called the pelvic cavity, is the lower part of the body and consists mainly of the reproductive organs (sex organs) and the rectum, while the pelvic floor at the bottom of the cavity helps in support. abdominal organs.
In mammals, the pelvic bone has a gap in the middle, significantly greater in women than in men. Those who are young pass through this gap when they are born.
Video Pelvis
Structure
The pelvic region of the torso is the bottom of the stem, between the abdomen and thigh. It includes several structures: pelvic bone, pelvic cavity, pelvic floor, and perineum. The bone pelvis (pelvic skeleton) is part of the skeleton embedded in the pelvic area of ​​the torso. It is divided into a pelvic corset and a hip spine. The pelvic girdle is composed of appendicular pelvic bone (ilium, iscium, and pubis), which connects the pelvic region of the spine to the lower limb. The hipbone consists of a sacrum and a coccyx bone.
- the pelvic cavity , usually defined as a small portion of the chamber covered by the pelvis, is limited by the full pelvis above and the pelvic floor below; as an alternative, the pelvic cavity is sometimes also defined as the entire space enclosed by the pelvic skeleton, divided into:
- larger (or wrong) pelvis, above the hips
- lower (or true) pelvis under the hips
- pelvic floor (or the pelvic diaphragm), under the pelvic cavity
- the perineum , below the pelvic floor
bone bone
The pelvic skeleton is posteriorly formed (in the back area), by the sacrum and the tail bone and laterally and anteriorly (front and sideways), by a pair of hip bones. Each hip bone consists of 3 parts, ilium, iscium, and pubis. During childhood, this section is a separate bone, joining the triradiate cartilage. During puberty, they join together to form one bone.
Pelvic cavity
The pelvic cavity is the body cavity that is bounded by the pelvic bone and which mainly contains the reproductive and rectal organs.
The difference made between the lower or lower pelvis is lower than the terminal line, and the larger or false pelvis above it. Hole pelvis or pelvis superior hole, which leads to a lower pelvis, bounded by cape, ilium curve, iliopubic eminence, pekten pubis, and the top of the symphysis pubis. The pelvic inferior pelvis or pelvic outlet is the area between the subpubic or pubic angles, ischemic tuberosity and coccyx.
- Ligaments: obturator membrane, inguinal ligament (lakun lakunar, iliopectineum arch)
Alternatively, the pelvis is divided into three areas: inlet, midplane, and outlet.
Pelvic floor
The pelvic floor has two conflicting functions: One is to close the pelvic cavity and the abdomen and bear the weight of the visceral organ; the other is to control the opening of the rectum and the urogenital organs that penetrate the pelvic floor and make it weaker. To achieve these two tasks, the pelvic floor consists of several overlapping muscle sheets and connective tissue.
The pelvic diaphragm is composed of the levator ani and coccygeus muscle. It arises between the symphysis and the iscone spine and congregates in the anococcygeal bone of the tail and ligaments that extend between the coccyx end and the anal hiatus. This leaves a gap for anal and urogenital openings. Because of the wide openings of the genitals, which are wider in women, a second closure mechanism is required. The urogenital diaphragm consists primarily of the inner transverse perineum arising from the ischial flax and inferior pubis and extends to the urogential hiatus. The urogenital diaphragm is reinforced posteriorly by a shallow transverse perineal.
Anal sphincters and external urethra cover the anus and urethra. The first is surrounded by bulbospongiosus that narrows the vaginal introitus in women and surrounds the corpus spongiosum in men. Ischiocavernosus squeezes blood into the penis of the corpus cavernosa and clitoridis.
Variations
Modern humans are largely characterized by bipedal motion and large brains. Because the pelvis is essential for both movement and childbirth, natural selection has been confronted by two conflicting demands: widespread birth canal and driving efficiency, the so-called "obstetrical dilemma". The female pelvis, or gynecoid pelvis , has evolved to the maximum width for labor - a wider pelvis will prevent a woman from walking. In contrast, human male pelvic bone is not limited by the need for childbirth and is therefore more optimized for bipedal movement.
The main differences between true and false hips of men and women include:
- The female pelvis is larger and wider than the higher, narrower, more compact male pelvis.
- The female inlet channel is larger and oval in shape, while the male promontory above projected further (ie more heart-shaped male niches).
- The pelvic side of a man gathers from the inlet to the outlet, while the female side of the pelvis is wider.
- The angle between acute inferior pubic rami (70 degrees) in men, but dull (90-100 degrees) in women. Thus, this angle is called the subpubic angle of the male and the pubic arch in the female. In addition, the bone that forms the angle/arch is more concave in the female but straight to the male.
- The distance between small ischia bones in males, making outlets narrow, but large in women, which have relatively large outlets. The ischial spines and tuberosity are more severe and projected further into the pelvic cavity in males. Sciatic scoots are larger wider in women.
- The iliac peak is higher and clearer in males, making the male false pelvis deeper and narrower than in females.
- Male sacrum is long, narrow, straight, and has a protruding sacred horn. Female sacrum is shorter, wider, more curved to the posterior, and has a slightly prominent headland.
- Acetabula is wider in women than in men. In men, facial acetabulum is more lateral, while the face is more anterior in women. As a result, when a man on foot can move forward and backward in one area. In females, the legs should swing forward and inward, from where the head is spinning from the thighbone moving the leg back on another plane. This change in the angle of the femoral head provides a characteristic female walking style (ie hip swing).
Maps Pelvis
Development
Each side of the pelvis is formed as a cartilage, which hardens as the three major bones that remain separated through childhood: ilium, iscium, pubis. At birth, the entire hip joint (acetabulum area and upper femur) is still made of cartilage (but there may be a small piece of bone in the major trochanter of the femur); this makes it difficult to detect congenital hip dislocations by X-raying.
"In terms of comparative anatomy the human shoulder blade represents two bones that have fused together, the right (dorsal) spinal and the corral (ventral).The epiphyseal line across the glenoid cavity is the fusion line, they are the counterparts of the ilium and iscium of the pelvic girdle. "
There is early evidence that the pelvis continues to widen for a lifetime.
Function
The pelvic skeleton is a hollow-shaped ring of bone connecting the vertebral column to the femora.
Its main function is to bear the upper body weight while sitting and standing, transfer the weight from the axial skeleton to the lower appendicular bone as it stands and walks, and provides attachment to and restrain the strength of strong muscles and posture.. Compared with the corset of the shoulder, the pelvic girdle is so strong and stiff.
Its secondary function is to hold and protect the pelvic viscera and abdominopelvis (the inferior portion of the urinary tract, internal reproductive organs), providing attachment to external reproductive organs and muscles and related membranes.
As a mechanical structure
The pelvic girdle consists of two hip bones. The hip bone is connected to each other anteriorly in the symphysis pubis, and posterior to the sacrum on the sacroiliac joint to form the pelvic ring. This ring is very stable and allows very small mobility, a prerequisite for transmitting load from the trunk to the lower limbs.
As a mechanical structure, the pelvis can be regarded as four roughly triangular and circular rings. Each superior ring is formed by the iliac bone; the anterior side extends from the acetabulum to the anterior superior iliac spine; the posterior side reaches from above the acetabulum to the sacroiliac joint; and the third side is formed by a palpable iliac crest. The lower ring, formed by the pubic and iskial bone flakes, supports the acetabulum and rotates 80-90 degrees in relation to the superior ring.
An alternative approach is to consider the pelvic portion of an integrated mechanical system based on the tensegrity icosahedron as an infinite element. Such systems are able to withstand omnidirectional forces - from holding back to childbirth - and, as systems that require low energy, are favored by natural selection.
The angle of the pelvis is the most important element of human posture and adjusted in the hip. This is also one of the rare things that can be measured on posture assessment. A simple measurement method is described by the English orthopedist Philip Willes and is done using an inclinometer.
As anchor for muscle
The lumbosacral joint, between the sacrum and the last lumbar vertebra, has, like all vertebral joints, intervertebral discs, anterior and posterior ligaments, flava ligaments, interspinous and supraspinous ligaments, and synovial joints between the articular processes of the two bones. In addition to these ligaments the joint is strengthened by umbilumbar and lateral lumbosacral ligaments. The iliolumbar ligament passes between the tip of the transverse process of the fifth lumbar vertebra and the posterior part of the iliac crest. Lateral lumbosacral ligaments, partially continued with the iliolumbar ligament, pass below the lower limit of the fifth vertebral transverse process to the sacral ala. Possible movements in the lumbosacral joint are flexion and extension, a small amount of lateral flexion (from 7 degrees in childhood to 1 degree in adults), but no axial rotation. Between the ages of 2-13 joints are responsible for as much as 75% (about 18 degrees) of flexion and extension in the lumbar spine. From the age of 35 ligaments simply limit the range of motion.
The three extracapsular ligaments of the hip joint - iliofemoral, ischiofemoral, and pubofemoral ligaments - form a twisting mechanism encircling the neck of the femur. When seated, with the hip joint flexed, this ligament becomes weak allowing a high level of mobility in the joint. When standing, with elongated hip joints, the ligament revolves around the femoral neck, pushing the femoral head firmly into the Acetabulum, thus stabilizing the joint. The orbicularis zone helps in maintaining contact in the joint by acting like a buttonhole in the femoral head. The intracapsular ligament, the terry ligament, transmits the healthy blood vessels of the femoral head.
Junctions
Both pelvic bones join anteriorly in the symphysis pubis by fibrous cartilage which is covered by hyaline cartilage, interpubic disk, where non-synovial cavities may exist. Two ligaments, superior and inferior pubic ligaments, strengthen the symphysis.
The second sacroiliac joint , formed between the auricular surface of the sacrum and the two hip bones. is an amphiarthroses, an almost immobile joint that is flanked by a tightly tightened joint capsule. This capsule is reinforced by ventraliliary, interosseous, and dorsal ventroiliac ligaments. The most important accessory ligaments of the sacroiliac joint are sacrospinous and sacrotuberous ligaments that stabilize the hip bone in the sacrum and prevent the promonotory from tilting forward. In addition, these two ligaments convert larger and smaller sciatic bumps into larger and smaller foramina, a pair of important pelvic openings. The iliolumbar ligament is a strong ligament that connects the tip of the transverse process of the fifth lumbar vertebra to the posterior portion of the inner lobe of the iliac crest. This may be regarded as the lower boundary of the thoracolumbar fascia and is sometimes accompanied by smaller ligament bands passing between the fourth vertebral lumbar and the iliac crown. The lateral lumbosacral ligament partially continues with the iliolumbar ligament. It passes between the transverse process from the fifth vertebra to the sacrum ala where it mingles with the anterior sacroiliac ligament.
The joint between the sacrum and coccyx, the sacrococcygeal symphysis, is amplified by a series of ligaments. The anterior sacrococcygeal ligament is an extension of the anterior longitudinal ligament (ALL) that runs on the anterior side of the vertebral body. Irregular fibers blend with the periosteum. The posterior sacrococcygeal ligament has a deep and shallow portion, the first being a flat band corresponding to the posterior longitudinal ligament (PLL) and the latter corresponding to the flava ligament. Several other ligaments complement the foramen of the last sacral nerve.
Intrinsic shoulder and back
The inferior part of latissimus dorsi, one of the upper limb muscles, arises from the posterior third of the iliac peak. His actions on the shoulder joint are internal rotation, adduction, and retroversion. It also contributes to respiration (ie cough). When the arm is added, latissimus dorsi can pull it back and toward the medial until the back of the hand covers the buttocks.
In the longitudinal osteofibrous channel on both sides of the spine there is a group of muscles called the spina erector that is divided into shallow and medial lateral channels. In the lateral tract, iliocostalis lumborum and longissimus thoracis are derived from the back of the sacrum and the posterior part of the iliac crest. Contraction of these muscles bilaterally extends the spine and unilateral contractions bend the spine to the same side. Medial channels have "straight" (interspinal, intertransversarii, and spinal) and "oblique" components (multifidus and semispinalis), both extending between the vertebral processes; the former acts similarly to the lateral channel muscles, while the latter works unilaterally as spinal and bilateral extensors as spinal rotation. In the medial channel, multifidi comes from the sacrum.
Abdomen
Abdominal wall muscles are divided into shallow and deep groups.
The superficial group is divided into the lateral and medial groups. In the medial shallow group, on both sides of the abdominal wall center, the rectus abdominis extends from the V-VII rib bones and the sternum to the top of the pubis. At the lower end of the rectus abdominis, the pyramid suspends linea alba . The lateral superficial muscles, transverse and external and internal oblique muscles, originate from the ribs and at the pelvis (the iliac symbol and the inguinal ligament) and attach to the anterior and posterior layers of the rectus sheath.
Stretching the stem (bending forward) is essentially the movement of the rectus muscles, while lateral flexion (side bend) is achieved by contracting the obliques together with the quadratus lumborum and intrinsic back muscles. Lateral rotation (turning rod or pelvis to the side) is achieved by contracting an internal slant on one side and an external oblique on the other. The main function of transversus is to produce abdominal pressure to constrict the abdominal cavity and pull the diaphragm upward.
There are two muscles in the inner or posterior group. Quadratus lumborum arises from the posterior part of the iliac crest and extends to the ribs XII and lumbar vertebra I-IV. Unilaterally bend the rod to the side and bilaterally pull the 12th rib down and help in expiration. The iliopsoas consist of psoas major (and sometimes minor psoas) and iliacus, muscles with separate origins but common insertion on small trochanters of the femur. Of these, only iliacus is attached to the pelvis (fossa iliac). However, the psoas pass through the pelvis and therefore function on two joints, it topography is classified as a posterior but functional abdominal muscle as a hip muscle. Iliopsoas flex and externally rotate the hip joint, while unilateral contractions bend lateral stems and bilateral contractions increase the stem from the supine position.
Hips and thighs
The hip muscles are divided into dorsal and ventral groups.
The back hip muscles are either inserted into the lower trochanter region (anterior or inner group) or the major trochanter (posterior or outer group). Anterior, psoas major (and sometimes minor psoas) originate along the spine between the ribs and the pelvis. Iliacus is derived from the iliac fossa to join the psoas in iliopubic eminence to form iliopsoas which are fed into the lower trochanters. The iliopsoas are the most powerful hip flexors.
Posterior groups include maximus gluteii, medius, and minimus. Maximus has a wide origin extending from the posterior part of the iliac crest and along the sacrum and tailbone, and has two separate inserts: the proximal radiating to the iliotibial and distal channels inserting into the gluteal tuberosity on the posterior side of the femoral shaft. It is primarily an extensor and lateral rotator of the hip joint, but, because of its bipartite insertion, it can both adduct and kidnap the hip. Medius and minimus appear on the external surface of the ilium and both are fed into the greater trochanter. Their anterior fibers are the rotator and the medial flexor while the posterior fibers are the lateral and extensor rotators. Piriformis begins on the ventral side of the sacrum and is fed into the trochanter major. These abducts and lateral rotate the hip in upright posture and help extend the thighs. The tensor fasciae latae appears on the anterior superior iliac spine and inserts it into the iliotibial canal. It presses the head of the femur into the acetabulum and flexes, medially spins, and abducts the hip.
The ventral hip muscles are important in controlling the body's balance. The internal and external obturator muscles along with the quadratus femoris are the lateral rotators of the hip. Together they are stronger than the medial rotator and therefore the feet pointed out in the normal position to get better support. The obturators have their origins on both sides of the foramen obturator and are inserted into the trochanteric fossa on the femur. Quadratus appears on the ischial tuberosity and is fed into the intertrochanteric peak. The superior and inferior gemelli, arising from the iscia spine and the respective ischial tuberosities, may be considered the marginal head of the obturator internus, and its primary function is to aid this muscle.
The thigh muscle can be divided into adductor (medial group), extensor (anterior group), and flexor (posterior group). The extensor and flexor act on the knee joint, whereas the adductors act mainly on the hip joint.
Thigh adductors have their origins in the inferior bone of the pubic bone and, with the exception of gracilis, are inserted along the femoral shaft. Together with sartorius and semitendinosus, gracilis reaches beyond the knee to their common insertion on the tibia.
The anterior thigh muscle forms the quadriceps inserted on the patella with a common tendon. Three of the four muscles are from the femur, while the rectus femoris arises from the anterior inferior iliac spine and thus are the only of the four that act on two joints.
The posterior thigh muscle is derived from the inferior iscial ramus, except for the short head of biceps femoris. Semitendinosus and semimembranosus are inserted on the tibia on the medial side of the knee, while the biceps femoris are inserted into the fibula, on the lateral side of the knee.
In pregnancy and delivery
In the final stages of pregnancy the fetal head is aligned in the pelvis. Also joints softened due to the effects of pregnancy hormones. These factors can cause pelvic joint pain (pubic symphysis dysfunction or SPD). As the end of the pregnancy approaches, the ligaments of the sacroiliac joint relax, allowing the pelvis to dilate outward; this is easily seen in cows.
During labor (except through cesarean section) the fetus passes through the opening of the uterus pelvic opening .
Clinical interests
Hip fractures often affect the elderly and occur more frequently in women, and this is often due to osteoporosis. There are also various types of pelvic fractures that are often caused by traffic accidents.
Pelvic pain generally, can attack anyone and has various causes; endometriosis in women, bowel adhesion, irritable bowel syndrome, and interstitial cystitis.
There are many variations of pelvic anatomy. In women the pelvis may be much larger than normal, known as a giant pelvis or a large, or much smaller, pelvis known as reduced pelvis or > justo minor pelvis . Other variations include pelvis android pelvis normal form of male pelvis, in women this form can prove problematic during childbirth.
History
Caldwell-Moloy Classification
During the measurement of 20th century pelvimetry made in pregnant women to determine whether natural birth will be possible, current practice is limited to cases where certain problems are suspected or follow cesarean delivery. William Edgar Caldwell and Howard Carmen Moloy studied a collection of skeletal throwers and thousands of stereoscopic radiograms and finally identified three types of women's throwers plus masculine types. In 1933 and 1934 they published their typology, including the Greek names since then which are often quoted in various handbooks: Gynaecoid ( gyne , female), anthropoid ( anthropos , human), platypelloid ( platys , flat), and android ( aner , man).
- The gynaecoid pelvis is the normal female pelvis called. Inlet channel slightly oval, with larger transverse diameter, or round. The interior walls are straight, the subpubic arch width, the sacrum shows the average tendency to the rear, and the larger sciatic notation is well rounded. Since this type is broad and well proportioned there is little or no difficulty in labor. Caldwell and co-workers found gynaecoid deposits in about 50 percent of specimens.
- The platypelloid placemant has wide and wide-width, wide anterior, larger male-type ski slots, and has a short-curved inside that reduces the diameter of the lower pelvis. This is similar to a rachitic pelvis in which the soft bone extends laterally because the weight of the upper body results in reduced anteroposterior diameter. Childbirth with this type of pelvis is associated with problems, such as transverse arrest. Less than 3 percent of women have this type of pelvis.
- The pelvic android is a female pelvis with masculine features, including a wedge or heart-shaped inlet caused by a prominent sacrum and anterior segment of the triangle. A reduced pelvic outlet often causes problems during childbirth. In 1939 Caldwell discovered this species in a third of white women and in one-sixth of non-white women.
- The anthropoid rim is marked with an oval shape with larger anteroposterior diameter. It has a straight wall, a small subpubic arch, and a large sacrosciatic notch. Sciatic spines are placed widely apart and sacrum is usually straight, causing unobstructed pelvis. Caldwell found this species in a quarter of white women and nearly half of non-white women.
However, Caldwell and Moloy then complicate this simple four-part scheme by dividing the pelvic channel into a posterior and anterior segment. They named the pelvis according to the anterior segment and affixed another type corresponding to the posterior segment character (ie anthropoid-android) and ended up with no less than 14 morphologies. Regardless of the popularity of this simple classification, the pelvis is much more complicated than this because the pelvis can have different dimensions at different levels of the birth canal.
Caldwell and Moloy also classify women physically by their pelvic type: gynaecoid type has small shoulders, small waist and wide hips; the android type looks square in the back; and the anthropoid type has broad shoulders and narrow hips. Finally, in their article they describe all types of non-gynaecoid or "mixed" pelves as "abnormal", a word inherent in the medical world even though at least 50 percent of women have this "abnormal" pelvis.
The classifications of Caldwell and Moloy are influenced by earlier classifications that attempt to define an ideal female pelvis, treating any deviation from this ideal as impeded dysfunction and causes of labor. In 19th century anthropologists and others see the evolutionary scheme in this pelvic typology, the scheme has since been refuted by archeology. Since 1950 malnutrition is considered to be one of the major factors affecting the shape of the pelvis in the Third World although there are at least some genetic components for variation in pelvic morphology.
Currently the obstetric conformity of female pelvis is assessed by ultrasound. The dimensions of the fetal head and the birth canal are measured and compared accurately, and the feasibility of labor is predictable.
Other animals
The pelvic girdle is present in the early vertebrates, and can be traced back to the paired fish fins that are some of the earliest chordates.
The pelvic form, especially the iliac crest, the shape and depth of the acetabula, reflects the driving force and animal body mass. In bipedal mammals, iliac crest is parallel to vertically oriented sacroiliac joints, where in four-legged mammals they are parallel to the horizontally oriented sacroiliac joint. In severe mammals, especially in four-legged animals, pelvis tends to be more vertical oriented as it allows the pelvis to support greater weight without dislocation of sacroiliac joints or adding torque to the vertebral column.
In outpatient mammals, acetabules are superficial and open to allow for wider pelvic movement, including significant abduction, compared with polar mammals. The lengths of ilium and iscium and their angles relative to the acetabulum are functionally important because they determine the moment arms for the hip extensor muscles that provide momentum during movement.
In addition to this, the relatively wide (front to back) shape of the pelvis provides greater influence for the gluteus medius and minimus. These muscles are responsible for hip abduction that plays an integral role in upright balance.
Primates
In primates, the pelvis consists of four parts - the left and right hip bones that meet in the midline in a ventral way and are set to the dorsal sac and the coccyx. Each hip bone is composed of three components, ilium, iscium, and pubis, and at the time of sexual maturation these bones become fused together, although there is never any movement between them. In humans, the ventral joint from the pubic bone is closed.
Great apes, such as Pongo (orangutan), Gorilla (gorilla), Australopithecus afarensis (Lucy), and Pan troglodytes (chimpanzees), has three longer pelvic planes with maximum diameter in the sagittal plane.
Evolution
The current morphology of the pelvis is inherited from our four-legged ancestral pelvis. The most striking feature of pelvic evolution in primates is the widening and shortening of the blades called ilium. Because of the pressure involved in bipedal movement, the thigh muscles move the thigh forward and backward, providing the power for bi-pedal and quadrupedal drive.
Source of the article : Wikipedia
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