Crotch limited front of the angle formed pubic bones, behind - the tip of the coccyx, outside - sciatic mounds, is the bottom of the pelvis (Fig. 1 and 2). In obstetrics crotch call the space between the rear soldering of the labia majora and anal hole. Crotch has a diamond shape; the line connecting the sciatic hills, divided into two triangles: front - urine-Polo-howling through which women held the urethra and vagina, male - urethra, and the back - anal (anal) triangle, which passes through the rectum.

male crotch
Fig. 1. Muscle and fascia male crotch (left fascia removed): 1 - onion-like muscle; 2 - sciatic-cavernous muscle; 3 - urogenital diaphragm; 4 - surface transverse muscle of perineum; 5 - muscle lifting the anus; 6 - most gluteus; 7 - anus; 8 - anal-PC bundle; 9 - coccyx; 10 - the outer sphincter anus; 11 - gluteal fascia; 12 - the lower fascia diaphragm; 13 - sciatic-pryamokishechnye hole; 14 - sciatic hill; 15 - wide fascia; 16 - superficial fascia of the perineum.

women's crotch
Fig. 2. Muscle and fascia of the female perineum (left fascia removed): 1 - the head of the clitoris; 2 - sciatic-cavernous muscle; 3 - top fascia of the urogenital diaphragm; 4 - the lower fascia urogenital diaphragm; 5 - deep transverse muscle of perineum; 6 - surface transverse muscle of perineum; 7 - anus; 8 - the outer sphincter anus; 9 - krestovnikova link; 10 - large gluteus; 11 - sacral-awned bundle; 12 - the muscle that raises the anus; 13 - anal-sacral link; 14 - gluteal fascia; 15 - lower fascia of your pelvic floor; 16 - onion-like muscle; 17 - the vagina; 18 - superficial fascia of the perineum; 19 - the outer opening of the urethra.

Women crotch much shorter than in men. Urogenital triangle in men is a tightly stretched muscular-fascial plate formed by urethral sphincter and deep transverse muscle of perineum, covered the fascia. So they fractures of the pelvis often break the urethra. Women tissue in the urinary triangle more pliable, breaks rare.
The skin of the perineum thin, pigmented and sedentary, subcutaneous tissue and superficial fascia of the more developed to the back, where lies the external sphincter anus. Deeper is its own fascia covering three muscles located in a triangle with both sides: the sciatic-cavernous, bulbous-spongy and surface transverse muscle of perineum. Under its own fascia are cavernous and spongy body of the penis. Urogenital triangle drawn urogenital diaphragm back connects to the anal sphincter, forming on the middle line of the tendon center of the perineum, which is the border between anal and urinary departments. The most large - pair muscle lifting the anus, together with the PC muscle and fascia forms the pelvic floor. Vessels in this area away from the trunk of domestic private parts arteries, nerves from both internal nerve.

Crotch (perineum label) - a set of tissue located between anal hole and outer sexual organs in the sagittal plane and between sciatic mounds in front. Under obstetric crotch understand the space between the rear soldering of private parts of the lips and anus. In a broader sense, the perineum regio perinealis) understand the scope of the pelvic outlet, closed the mobile-muscular-fascial plate - pelvic diaphragm (diaphragma pelvis).
Anatomy. Bone borders perineum are: front - the angle between the pubic bones, behind - the tip of the coccyx, and from sides - sciatic mounds (Fig. 1 and 2).

Fig. 1. Male crotch and adjacent areas: 1 - reg. glutea; 2 - reg. pudendalis (BNA); 3 - reg. urogenitalis (BNA); 4 - reg. perinealis (BNA); 5 - reg. analis; 6 - reg. sacralis.

Fig. 2. Female crotch and adjacent areas: 1 - reg. pudendalis (BNA); 2 - reg. perinealis (BNA); 3 - reg. glutea; 4 - reg. sacralis; 5 - reg. analis; 6 - reg. urogenitalis (BNA).

When divorced hips crotch has a diamond shape. Cross the line drawn through the middle of the diamond between the sciatic mounds, divides this diamond on two triangles: rear (pryamokishechnye), or anal area (regio analis), and front (urogenital), or urogenital region (regio urogenitalis); in front of it is the private parts of the region (regio pudendalis). Through pryamokishechnye triangle passes rectum. Through urinary triangle women are the vagina and the urethra in men - only the urethra.
Urogenital triangle made urogenital diaphragm (diaphragma urogenitale). It is a muscle record, occupying the angle between the pubic bones. Women these bones deployed more than men. In pathological cases, urogenital diaphragm becomes pliable and not holding the inwards, resulting in, for example, the loss of the uterus.
Distinguish education actually the perineum (the muscles, fascia, fat pillows on either side of the rectum)associated with it (the feet of the cavernous bodies of the penis, onion spongy body of the urethra, Bulbo-urethral gland), and education, partly located in the perineal or only passing through it (the urethra, rectum, vessels and nerves of the vulva, vagina).

muscle and fascia male crotch
Fig. 3. Muscle and fascia male crotch (bottom view; left fascia removed): 1 - m. bulbospongiosus; 2 - m. ischiocavernosus; 3 - diaphragma urogenitale; 4 - m. transversa perinei superticialis; 5 - m. levator ani; 6 - m. gluteus max.; 7 - anus; 8 - lig. anococcygeum; 9 - os coccygis; 10 - m. sphincter ani ext.; 11 - fascia glutea (BNA); 12 - fascia diaphragmatis pelvis inf.; 13 - fossa ischiorectalis; 14 - tuber ischiadicum; 15 - fascia lata; 16 - fascia superficialis perinei.

muscle and fascia female perineum
Fig. 4. Muscle and fascia of the female perineum (bottom left fascia removed): 1 - glans clitoridis; 2 - m. ischiocavernosus; 3 - fascia diaphragmatis urogenitalis inf. (membrana perinei); 4 - fascia diaphragmatis urogenitalis sup.; 5 - m. transversus perinei profundus; 6 - m. transversus perinei superficialis; 7 - anus; 8 - m. sphincter ani ext.; 9 - lig. sacrotuberale; 10 - m. gluteus max.; 11 - lig. sacrospinale; 12 - m. levator ani; 13 - lig. anococcygeum; 14 - fascia glutaea (BNA); 15 - fascia diaphragmatis pelvis; 16 - m. bulbospongiosus; 17 - orificium vaginae (BNA); 18 - fascia superficialis perinei; 19 - ostium urethrae ext.

Pelvic diaphragm (Fig. 3 and 4) consists of two pairs of muscles: the muscles that raise the anus (m. levator ani), and PC (m. coccygeus). The muscle lifting the anus,- steam thin plate with a triangular form, closes below the pelvic cavity, forming together with its pair likeness of a funnel, the bottleneck is drawn to the median line and the bottom. Starting tendinous arc (arcus tendineus fasciae pelvis), which runs along the side wall of the small pelvis from the symphysis to back spine. Muscle bundles converge, part of their bypasses the rectum back and forms with beams opposite side of the loop. Other bundles are sent down, back and medial, cover with lateral sides of the prostate gland (for women bladder and the vagina and the rectum and partly intertwined with the muscles of these bodies. Passing through a direct gut, a large part of the muscle bundles ends in the coccyx; anal PC ligament (lig. anococcygeum) they are attached to the top and side edges and to the front of sacrococcygeal together (lig. sacrococcygeum ventrale). Muscle strengthening of the fibrous part of the pelvic diaphragm, raises the bottom of the pelvis, pulls anal part of the rectum forward and up, puts it back to front and helps the external and internal sphincter muscles to squeeze her; for women, also attracts the back wall of the vagina to the front and together with an onion-cavernous muscle (m. bulbospongiosus) big vagina Innervation crotch - branches III and IV bottom of the sacral nerves (from PC plexus).
The PC muscle (m. coccygeus) starts from the sciatic spine and fan-shaped expanding, goes to the side edge of the I - II lower sacral and II-III coccygeal vertebrae; it is closely connected with sacral-spinous bundle (lig. sacrospinale). Of great importance in connection with the vertical position of the human body: with this bundle and hips bugornea ligament (lig. sacrotuberale) takes part in keeping the sacrum in relation to the ring bones. Innervation is the same as the previous.
The external sphincter anal holes (m. sphincter ani externus) unpaired, flat, surrounded by a ring of the rectum and the anal opening. Along with the internal sphincter and the muscle that raises the anus tightly squeezes the anal opening.
Urogenital diaphragm also formed several muscles.
Urethral sphincter (m. sphincter urethrae) koltseobrazno membrane surrounds part of the urethra; to the periphery fiber radiate outwards and are attached to the pubic bone. Separate the reduction in radial fiber reveals compressed channel.
Deep transverse muscle of perineum (m. transversus perinei profundus) steam, has the form of thin plates. Begins on the lower branches of the sciatic and pubic bones; fiber muscles are intertwined in the middle line with similar fibers opposite side, forming a bead. In the upper part of the genitourinary triangle medial ends of the fibers of both muscles are woven into the urethral sphincter.
The superficial muscles of the urogenital diaphragm connected with external sex organs. Muscular elements in women developed significantly weaker than men. Women have only the muscles surrounding the vagina (m. bulbospongiosus, s. constrictor cunni). In men, there are bulbous-cavernous, sciatic-cavernous and surface transverse muscle of perineum (mm. bulbospongiosus, ischiocavernosus et transversus perinei superficialis).
Pelvic fascia (fascia pelvis) - continuation of the fascia transverse abdominal muscles, covers the top surface of the pelvic diaphragm. Densified part of the pelvic fascia - top fascia of the pelvic diaphragm (fascia diaphragmatis pelvis superior), covering the inside of the muscle that raises the anus, can passively resist the pressure of the pelvic viscera. On the sides of the symphysis in the direction of the bladder and prostate pelvic fascia thickened and is called the fascia of the prostate (fascia prostatae).
On both sides of the lower part of the rectum on the outer surface of the muscle, raising the anus, are significant excavation - sciatic-pryamokishechnye fossa (fossae ischiorectales), due to the inclined funnel shape of the muscles. Outside these pits is limited to the mound and branches ischial bones together with the aponeurosis of the internal locking muscle. In addition adipose tissue, there are vessels and nerves of the perineum.
Superficial fascia of the perineum (fascia superficialis perinei) is divided into superficial and deep plates covering the muscles of the urogenital diaphragm.
The lower fascia urogenital diaphragm (fascia diaphragmatis urogenitalis inferior) is strengthened between her three cavernous bodies of the penis and the adjacent muscles.
Top fascia of the urogenital diaphragm (fascia diaphragmatis urogenitalis superior) covers on top of deep transverse muscle of perineum and urethral sphincter.
The blood supply of the perineum with a bawdy artery (a. pudenda interna). Same vein accompany artery. Lymph outflow occurs in the superficial inguinal lymph nodes. Innervation crotch - bawdy nerve (n. pudendus)and perineal branch back cutaneous nerve of thigh (rr. perineales n. cutaneus femoris posterior).