Anatomy of the pelvis: structure, functions

The pelvic region includes pelvic bones, sacrum, coccyx, pubic symphysis, as well as ligaments, joints and membranes. Some experts refer to it and the buttock area.

The article deals with pelvic anatomy: bone system, musculature, genital and excretory organs.

The pelvic system of the pelvis

The skeleton of the pelvis consists of pelvic bones, sacrum and coccygeal bone. Each of them is firmly fixed. The iliac bone, as well as the coccygeal articulation, connects with the sacrum.

The pelvis is divided into a large and a small section.

The first consists of sides with wings of the iliac bones. On the inner surface is the iliac pit, and outside - gluteal pits.

The small pelvis consists of a cylindrical cavity with an upper and a lower opening (i.e., an inlet and an outlet).

The osseous bone is slightly mobile, which helps women during childbirth. The pelvic anatomy of the pelvis has the following differences in men and women:

• The male pelvis is long and narrow, in women it is shorter and wider;
• The male cavity of the pelvis is conical, the female - cylindrical;
• The wings of the ilium in men are more vertical, in women - more horizontally;
• The branches of pubic bones in men make an angle of 70-75 degrees, in women 90-100 degrees;
• In men, the shape of the entrance reminds the heart (as on the cards), in women it is round, although it happens that women also have an entrance as a "card heart".

Bundles

Well developed ligaments fix four pelvic bones, the anatomy of which is discussed above. They are assisted by connecting three joints: a frontal fusion (two unpaired), sacroiliac (pair) and sacrococcygeal fusion.

One is located on the pubic bones from the upper edge, the other on the bottom. The third joints strengthen the joints of the sacral and iliac bones.

Muscular system of the pelvis

In this section, the anatomy of the pelvis is represented by parietal and visceral musculature. In the first part in the large pelvis there is a muscle consisting of three m.iliacus, m.psoas major and m.psoas minor interconnected. In the small pelvis this same parietal musculature is represented by pear-shaped muscle, internal blocking and coccygeal muscles.

Visceral musculature is involved in the formation of the pelvic diaphragm. It includes paired muscles that lift the anus and unpaired m.sphincter ani extremus.

Here are the pubic-coccygeal muscle, ilio-coccygeal, as well as the powerfully developed circular muscle of the distal part of the rectum.

Blood supply and lymphatic system

Blood enters the pelvis (anatomy here involves the involvement of the pelvic wall and internal organs) from the hypogastric artery. It is divided first into the front and back, and then to the other branches.

In the soft tissues of the large pelvis, blood flows through a single vessel of a.iliolumbalis, which branches into two terminal branches.

The walls of the pelvis provide four arteries:

• Lateral sacral;
• Blocking;
• Upper gluteal;
• Lower gluteal.

Vascular wall and retroperitoneal space are involved in the circulatory circulation . In a roundabout venous circle, the main veins pass between the large and small pelvis. There are abundant venous anastomoses located near the rectum wall and in its thickness, as well as under the peritoneum of the pelvis. When blocking large pelvic veins, the veins of the spine, waist, anterior abdominal wall and retroperitoneal tissue serve as roundabout ways.

Anatomy of the pelvis, like other systems, suggests the variability of the morphology of the vessels in the lymph.

The main lymphatic collectors from the pelvic organs are the iliac lymphatic plexus, distracting lymph.

Lymphatic vessels under the peritoneum mostly pass at the level of the middle floor of the pelvis.

Innervation

Nerves of this area are divided into:

• Somatic;
• Vegetative (parasympathetic and sympathetic).

The somatic system of nerves is represented by the sacral plexus associated with the lumbar plexus. Sympathetic - sacral part of the border trunks and unpaired coccygeal node. Parasympathetic nerves are nn.pelvici s.splanchnici sacrales.

Buttocks

Often the anatomy of the gluteal region is not included in the pelvis. However, topographically, it should be referred here, and not to the lower extremities. Therefore, we will briefly mention it.

Above the gluteal region is limited by the scab of the ilium, and from below - by the gluteal fold, under which is the gluteal groove. From the lateral side, you can represent a vertical line from a row of bones, and from the medial - both areas are separated by a megacollow slit.

Consider the anatomy here layer by line:

• The skin of this area is thick and dense;
• Subcutaneous tissue with superficial, middle and lower nerves is well developed;
• Then follows the surface plate of the gluteus fascia;
• The gluteus maximus;
• Gluteus fascia fascia;
• Fatty tissue between the large muscle and the middle layer of muscles;
• Middle layer of muscles;
• Deep layer of muscles;
• bones.

Excretory organs

Anatomy of the small pelvis includes an unpaired muscular organ - the bladder. It consists of the top, body, bottom and neck. One department here goes into another. Bottom fixed with urogenital diaphragm. When the bladder begins to fill, its shape becomes ovoid. With an empty bubble, the shape is close to saucer-like.

The blood supply comes from the system of the hypogastric artery, and the venous outflow is directed into the dense plexus plexus, which adjoins the lateral surfaces and the prostate gland.

Innervation is carried out by somatic and vegetative fibers.

The rectum begins to develop from embryonic rudiments. The upper part is derived from the endoderm, and the lower one appears by screwing from the surface of the ectodermal layer.

The rectum is at the level of the posterior part of the small pelvis. It is divided into three departments: upper, middle and lower.

The musculature is externally represented by powerful longitudinal fibers, and inside - by circular ones. Mucous consists of numerous folds. Innervation here is similar to what happens in the bladder.

Sexual system

Without the reproductive system it is impossible to consider the pelvis (structure). The anatomy of this area in both sexes consists of the sexual gland, the wolf body, the canal, the Mullerian duct, the sinus of the genitourinary and genital tubercles, folds and ridges.

The sex gland is laid in the lower back and turns into a testicle or ovary, respectively. The Wolffian body, canal and muller duct are also laid here. However, further on, the mullerian channels are differentiated in the female, and the male body has the wolf body and ducts.

The remaining rudiments are reflected on the external organs.

Ovary and ovary grow behind the peritoneum.

The male reproductive system is represented by:

• A cover of the testicle, consisting of skin, fleshy shell, Cooper fascia, cremaster, common and proprietary vaginal membrane, belly coat;
• The seminal gland;
• Lymphatic system;
• Appendage consisting of three divisions (head, body and tail);
• Spermatic cord;
• Seminal vesicles (hollow tubes with bayonet protrusions);
• Prostate gland (glandular-muscular organ between the diaphragm and the bottom of the bladder);
• A penis consisting of three sections (root, body and head);
• The urethra.

Anatomy of the female pelvis includes the reproductive system of:

• Uterus (derivative of Muller channels);
• Ovaries located in a special ovarian fossa;
• Fallopian tubes consisting of four sections (funnel, dilated part, isthmus and part perforating the wall);
• Vagina;
• External genitalia, consisting of large labia and vulva.

Crotch

This area is located from the slide to the top of the coccygeal bone of the pelvis.

Anatomy of the perineum in both men and women is divided into 2 areas: sham (front) and anal (back). An urogenital triangle corresponds to the front of the region, and the rectum from the back.

Conclusion

This is the structure of the pelvis as a whole. The anatomy of this area is certainly a complex system. The article gives only a brief overview of what it consists of and how it works.