Cholesterol
25.04.2019

Female pelvis. Features of the structure of the woman's pelvis. Female and male pelvis

Speaking about the physiological course of childbirth, it is necessary to take into account the state of the woman’s bone pelvis, since its correct age development, the usefulness of the pelvic floor muscles and the fetal head depends on how the birth will proceed. Let's take a quick look anatomical structure pelvis adult woman.

Structure bone skeleton, in particular the pelvis, depends on many reasons, including heredity, intrauterine development, transferred to childhood diseases, injuries, the presence of tumors, etc. play an important role.

A woman’s bony pelvis differs from a man’s, since one of its most important purposes is to participate in birth process. It, together with other reproductive organs, forms the birth canal through which the fetus moves.

The bones of the female pelvis are thinner, smoother, and less massive compared to the male pelvis. Basic distinctive feature The female pelvis is the plane of the entrance to the small pelvis, which in women has a transverse oval shape, and in men it has the shape of a “card heart”.

Anatomically, the female pelvis is lower, wider and larger in volume than the male pelvis. The pubic symphysis in the female pelvis is shorter than the male one. The sacrum of the female pelvis is wider, the sacral cavity is moderately curved. The pelvic cavity in women resembles a cylinder, and in men it narrows funnel-shaped downward. The pubic angle is wider - 90-1000, in men - 70-750. The tailbone protrudes anteriorly less than in the male pelvis. The ischial bones in the female pelvis are parallel to each other, and in the male pelvis they converge. All these differences have great importance during the birth process.

The pelvis of an adult woman consists of four bones: two pelvic, one sacral and one coccygeal, firmly connected to each other.

The pelvic bone, or innominate bone, consists of three bones up to 16-18 years of age, connected by cartilage in the acetabulum area: ilium, ischium and pubis. After puberty, the cartilages fuse together and a solid bone mass is formed - the pelvic bone.

Upper and lower branches The pubic bones in front are connected to each other by means of cartilage, forming a sedentary joint, which allows it to stretch somewhat during pregnancy, thus increasing the volume of the pelvis.

The sacrum and coccyx, consisting of individual vertebrae, form back wall pelvis

There are large and small pelvises. Highest value during pregnancy, it has a small pelvis, since it represents part of the birth canal. Its shape and size are of great importance during childbirth. In the small pelvis there are an entrance, a cavity and an exit. In the pelvic cavity there are wide and narrow parts. In accordance with this, four planes are distinguished: the plane of the entrance to the small pelvis, the plane of the wide part of the small pelvis, the plane of the narrow part of the small pelvis and the plane of the exit from the small pelvis. If you connect the midpoints of all straight dimensions of the small pelvis, you will get a line curved in the form of a hook, which is called the wire axis of the pelvis. The movement of the fetus along the birth canal occurs in the direction of the pelvic axis.

When measuring the pelvis, special importance should be attached to examining the lumbosacral region, the so-called Michaelis diamond. At normal sizes and the shape of the pelvis, the rhombus approaches a square; with an irregular pelvis, its shape and dimensions change (Fig. 8.15 (according to the book:)).

The upper corner of the diamond is the depression between the spinous process of the V lumbar vertebra and the beginning of the middle sacral crest. The lower angle corresponds to the apex of the sacrum, the lateral angles correspond to the posterosuperior spines iliac bones.

Rice. 8.15.A- Michaelis rhombus; b- measurement of external conjugates

The structure of the bone skeleton and, in particular, the pelvis depends on many reasons, among which heredity, intrauterine development, childhood illnesses, injuries, the presence of tumors, etc. play an important role. It is recommended to pay attention to the gait of the pregnant woman, how she sits and stands. A diagram of the bony female pelvis is shown in Fig. 8.16 (according to the book: ).


Rice. 8.16.Female pelvis:

1 - sacrum; 2 - ilium (wing); 3 - anterosuperior spine; 4 - anterior inferior spine; 5 - acetabulum; 6 - obturator foramen; 7 - ischial tuberosity; 8 - pubic arch; 9 - symphysis; 10 - entrance to the small pelvis; 11 - unnamed line

There are large and small pelvises. The small pelvis is of greatest importance during pregnancy, since it represents part of the birth canal. Its shape and size are very important during childbirth. In the small pelvis there are an entrance, a cavity and an exit. In the pelvic cavity there are wide and narrow parts. In accordance with this, four planes are distinguished: the plane of the entrance to the small pelvis, the plane of the wide part of the small pelvis, the plane of the narrow part of the small pelvis and the plane of the exit from the small pelvis. If you connect the midpoints of all straight dimensions of the small pelvis, you will get a line curved in the form of a hook, which is called the wire axis of the pelvis. The movement of the fetus along the birth canal occurs in the direction of the pelvic axis.

Tazomer - a special tool for measuring the size of the pelvis (Fig. 8.17 (according to the book: )).

Rice. 8.17.

1 - Distantia spinarum- the distance between the most distant points of the anterior, superior iliac spines; 2 - Distantia cristarum- the distance between the most distant points of the iliac crests; 3 - Distantia trochanterica- the distance between the most distant points of the trochanters of the femurs

Transverse dimensions of the pelvis:

  • distantia spinarum - 25-26 cm, this is the distance between the most distant points of the anterior, upper iliac spines;
  • disiantia cristarum - 28-29 cm, this is the distance between the most distant points of the iliac crests;
  • distantia trochanterica - 30-31 cm is the distance between the most distant points of the trochanters of the femurs.

To determine the direct dimensions of the pelvis, the external conjugate is measured with a pelvis meter - conjugata diagonals externa(20-21 cm) is the distance from the upper edge of the womb to the top of the Michaelis rhombus. When measuring the external conjugate, the woman in labor lies on her side, lower leg bent at a right angle, and the top one is extended (see Fig. 8.15).

To the most important internal dimensions pelvis include:

Dimensions of the entrance to the pelvis (Fig. 8.18 (according to the book:)

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