The bony base of the pelvis is formed by two pelvic bones, the sacrum and the coccyx. The pelvic cavity contains the loops of the small intestine and part of the large intestine, as well as genitourinary system. The upper external landmarks of the pelvis are the pubic and ilium bones, the sacrum. The lower part is limited by the coccyx and ischial tuberosities. The outlet from the pelvis is closed by the muscles and fascia of the perineum, which form the pelvic diaphragm.
In the area of the pelvic floor, formed by fascia and muscles, the pelvic diaphragm and the genitourinary diaphragm are distinguished. The pelvic diaphragm is formed mainly by the levator muscle anus. Its muscle fibers, connecting with the bundles of the opposite side, cover the wall of the lower part of the rectum and intertwine with the muscle fibers of the external anal sphincter.
The urogenital diaphragm is a deep transverse perineal muscle that fills the angle between the inferior rami of the pubis and ischium. Below the diaphragm is the perineal area.
The large and small pelvis are separated. The boundary between them is the boundary line. The pelvic cavity is divided into three sections (floors): peritoneal, subperitoneal and subcutaneous.
In women, the peritoneum at the transition from the posterior surface Bladder forms a shallow vesicouterine cavity on the anterior surface of the uterus. In front, the cervix and vagina are located subperitoneally. Having covered the fundus, body and cervix from behind, the peritoneum descends to the posterior fornix of the vagina and passes to the rectum, forming a deep rectal-uterine cavity.
Duplications of the peritoneum directed laterally from the uterus to the lateral walls of the pelvis are called the broad ligament of the uterus. Between the leaves of the broad ligament of the uterus there are the fallopian tube, the ligament of the ovary, the round ligament of the uterus and the ovarian artery and vein going to the ovary, lying in the ligament supporting the ovary. At the base of the ligament lie the ureter, uterine artery, venous plexus and uterovaginal nerve plexus. In addition to the broad ligaments, the uterus in its position is strengthened by the round ligaments, rectouterine and sacrouterine ligaments and the muscles of the genitourinary diaphragm, to which the vagina is fixed.
The ovaries are located behind the broad ligament of the uterus closer to the side walls of the pelvis. With the help of ligaments, the ovaries are connected to the corners of the uterus, and with the help of suspensory ligaments they are fixed to the side walls of the pelvis.
The subperitoneal section of the pelvis is located between the peritoneum and the parietal fascia, contains parts of organs that do not have peritoneal cover, the final parts of the ureters, vas deferens, seminal vesicles, prostate, in women - the cervix and part of the vagina, blood vessels, nerves, The lymph nodes and the loose fatty tissue surrounding them.
In the subperitoneal section of the small pelvis, two spurs of fascia pass in the sagittal plane; in front they are attached at the medial edge of the internal opening of the obturator canal, then, following from front to back, they merge with the fascia of the bladder, rectum and attach to the anterior surface of the sacrum, closer to the sacroiliac joint. In each of the spurs there are visceral branches of vessels and nerves leading to the pelvic organs.
In the frontal plane, as noted, between bladder, prostate and rectum in men, between the rectum and vagina in women there is a peritoneal-perineal aponeurosis, which, having reached the sagittal spurs, merges with them and reaches the anterior surface of the sacrum. Thus, the following parietal cellular spaces can be distinguished; prevesical, retrovesical, retrorectal and two lateral.
The retropubic cellular space is located between the pubic symphysis and the visceral fascia of the bladder. It is divided into preperitoneal (anterior) and prevesical spaces.
The prevesical space is relatively closed, triangular in shape, limited in front by the pubic symphysis, and behind by the prevesical fascia, on the sides by fixedly obliterated umbilical arteries. The prevesical space of the pelvis along the femoral canal communicates with the tissue of the anterior surface of the thigh, and along the cystic vessels - with the lateral tissue space of the pelvis. Through the prevesical space, extraperitoneal access to the bladder is performed when a suprapubic fistula is applied.
The retrovesical cellular space is located between back wall the bladder, covered with a visceral layer of the prevesical fascia, and the peritoneal-perineal aponeurosis. From the sides, this space is limited by the already described sagittal fascial spurs. The bottom is the pelvic urogenital diaphragm. For men, they are located here prostate, having a strong fascial capsule, the terminal parts of the ureters, vas deferens with their ampoules, seminal vesicles, loose tissue and prostatic venous plexus.
Purulent leaks from the retrovesical cellular space can spread into the cellular space of the bladder, into the area of the inguinal canal along the vas deferens, into the retroperitoneal cellular space along the ureters, into the urethra, and into the rectum.
The lateral cellular space of the pelvis (right and left) is located between the parietal and visceral fascia of the pelvis. The lower border of this space is the parietal fascia, which covers the levator ani muscle on top. At the back there is a connection with the retrointestinal parietal space. From below, the lateral tissue spaces can communicate with the ischiorectal tissue if there are gaps in the thickness of the levator ani muscle, or through gaps between this muscle and the obturator internus.
Thus, the lateral cellular spaces communicate with the visceral cellular spaces of all pelvic organs.
The posterior rectal tissue space is located between the rectum with its fascial capsule in front and the sacrum in the back. This cellular space is delimited from the lateral spaces of the pelvis by sagittal spurs running in the direction of the sacroiliac joint. Its lower border is formed by the coccygeus muscle.
In the fatty tissue of the retrorectal space at the top there is the superior rectal artery, then the median and branches of the lateral sacral arteries, the sacral section of the sympathetic trunk, branches from the parasympathetic centers of the sacral section spinal cord, sacral lymph nodes.
The spread of purulent leaks from the retrorectal space is possible into the retroperitoneal cellular space, the lateral parietal cellular spaces of the pelvis, and the visceral cellular space of the rectum (between the intestinal wall and its fascia).
Operational accesses to the retrorectal cellular space of the pelvis is carried out through an arcuate or median incision between the coccyx and the anus, or resection of the coccyx and sacrum is performed no higher than the third sacral vertebra.
Vessels of the subperitoneal region
At the level of the sacroiliac joint, the common iliac arteries are divided into external and internal branches. The internal iliac artery goes downwards and backwards and after 1.5–5 cm divides into anterior and posterior branches. The superior and inferior vesical arteries, uterine, middle rectal and parietal arteries (umbilical, obturator, inferior gluteal, internal genital) depart from the anterior branch. The parietal arteries (iliopsoas, lateral sacral, superior gluteal) depart from the posterior branch. The internal genital arteries enter the ischiorectal fossa through the lesser sciatic foramen.
Deoxygenated blood from the pelvic organs it flows into the venous plexuses (vesical, prostatic, uterine, vaginal). The latter give rise to veins of the same name as the arteries, usually double, which together with the parietal veins (superior and inferior gluteal, obturator, lateral sacral, internal genital) form the internal iliac vein. Blood from the rectal venous plexus partially flows through the superior rectal vein into the portal vein system.
The lymph nodes of the pelvis are represented by the iliac and sacral nodes. The iliac nodes are located along the external (lower) and common (upper) iliac arteries and veins (from 3 to 16 nodes) and receive lymph from lower limb, external genitalia, lower half of the anterior abdominal wall.
Rectum
The rectum is the terminal part of the intestinal tube and begins at the level of the II or upper edge of the III sacral vertebra, where the colon loses the mesentery and the longitudinal muscle fibers are evenly distributed over the entire surface of the intestine, and not in the form of three bands. The intestine ends in the anus.
The length of the rectum does not exceed 15 cm. Anterior to it in men are the bladder and prostate, ampoules of the vas deferens, seminal vesicles and the terminal parts of the ureters, in women - the vagina and cervix. The rectum in the sagittal plane forms a bend corresponding to the curvature of the sacrum, first in the direction from front to back (sacral bend), then in the opposite direction (perineal bend). At the same level, the rectum bends in the frontal plane, forming an angle open to the right.
The rectum has two main parts: pelvic and perineal. The pelvic part (10–12 cm long) lies above the pelvic diaphragm and has a suprampullary part and an ampulla (the wide part of the rectum. The suprampullary part of the rectum, together with the terminal part of the sigmoid colon, is called the rectosigmoid colon.
The anal canal (perineal part of the rectum) is 2.5–3 cm long and lies above the pelvic diaphragm. Adjacent to it on the sides is the fatty body of the ischial-anal fossa, in front - the bulb of the penis, covered with muscle and fascia, the posterior edge of the urogenital diaphragm and the tendon center of the perineum.
The rectum is covered in the upper part by the peritoneum on all sides, below - in the front and sides, and at the level of the IV sacral vertebra (and partially V) - only in the front. In the subperitoneal part, the rectum has a well-defined visceral fascia - the fascia of the rectum.
The mucous membrane of the upper part of the rectal ampulla forms 2 - 4 transverse folds. In the anal canal, longitudinal folds are separated by sinuses, the number of which ranges from 5 to 13, and the depth is often 3 - 4 mm. From below, the sinuses are limited by the anal valves, located 1.5 - 2 cm above the anus. The purpose of these folds is to relieve pressure feces to the pelvic floor.
The muscular layer of the rectum consists of an outer longitudinal and an inner circular layer. The outlet of the rectum is ring-shaped and enclosed under the skin by the external anal sphincter, consisting of striated muscle fibers (voluntary sphincter). At a distance of 3 - 4 cm from the anus, ring-shaped smooth muscle bundles, thickening, form the internal sphincter (involuntary). The fibers of the levator rectum muscle are woven between the fibers of the external and internal sphincter. At a distance of 10 cm from the anus, the annular muscles form another thickening - the third (involuntary) sphincter.
Arterial blood supply to the rectum is carried out mainly by the superior rectal artery (unpaired, final branch inferior mesenteric artery), which passes at the root of the mesentery of the sigmoid colon and at the back at the level of the beginning of the intestine is divided into 2 - 3 (sometimes 4) branches, which along the posterior and lateral surfaces of the intestine reach its lower part, where they connect with the branches of the middle and lower rectum arteries.
Middle rectal arteries (paired, from the internal iliac artery) supply blood to the lower parts of the rectum. They can have a large caliber, and sometimes are absent altogether.
The lower rectal arteries (paired) in the amount of 1 - 4 on each side depart from the internal genital arteries and, having passed through the tissue of the ischio-anal fossa, enter the wall of the rectum in the area of the external sphincter.
The veins corresponding to the arteries form plexuses in the wall of the rectum (rectal venous plexuses). There is a subcutaneous plexus (around the anus), submucosal, which in the lower part consists of tangles of veins penetrating between the bundles of circular muscles (hemorrhoidal zone), and subfascial (between the muscle layer and its own fascia). Venous outflow occurs through the superior rectal vein (which is the beginning of the inferior mesenteric vein), the middle rectal vein (flows into the internal iliac vein), and the inferior rectal vein (flows into the internal pudendal vein). Thus, in the wall of the rectum there is one of the portocaval anastomoses.
Lymphatic vessels from the subcutaneous lymphatic network around the anus below the anal valves are directed to the inguinal lymph nodes. From the posterior part of this network and from the networks of lymphatic capillaries of the posterior wall of the rectum in the area of attachment of the levator ani muscle, lymphatic vessels are directed to the sacral lymph nodes.
From the rectum area within 5 - 6 cm from the anus, the lymphatic vessels are directed on the one hand - along the lower and middle rectal blood vessels to the internal iliac lymph nodes, on the other - along the superior rectal artery to the nodes located along this vessel, down to the lower mesenteric lymph nodes.
Lymph flows into these same nodes from parts of the rectum lying above 5 - 6 cm from the anus. Thus, from the lower part of the rectum, the lymphatic vessels go up and to the sides, and from the upper part, upward.
The rectum is innervated by parasympathetic, sympathetic and spinal nerves. Sympathetic branches to the intestine approach the superior rectal artery in the form of the superior rectal plexus (from the inferior mesenteric plexus) and the middle rectal arteries, and independently in the form of the middle rectal plexus from the inferior hypogastric plexus. Through the same perivascular plexuses, parasympathetic branches approach the rectum, coming from the sacral part of the parasympathetic system in the form of pelvic splanchnic nerves. As part of the sacral spinal nerves pass sensory nerves, conveying a feeling of filling of the rectum.
The anal canal, external sphincter, and skin around the anus are innervated by the inferior rectal nerves, which arise from the pudendal nerve. These nerves contain sympathetic fibers that innervate the deep muscles of the rectum, and in particular the internal anal sphincter.
Bladder
Located in the anterior pelvis. The anterior surface of the bladder is adjacent to the pubic symphysis and the upper branches of the pubic bones, separated from them by a layer of loose tissue. connective tissue. The posterior surface of the bladder borders the ampulla of the rectum, the ampullae of the vas deferens, the seminal vesicles and the terminal parts of the ureters. Adjacent to the bladder above and on the sides are loops of the thin, sigmoid, and sometimes transverse colon and cecum separated from it by the peritoneum. The lower surface of the bladder and the initial part of the urethra are covered by the prostate. The vas deferens adjoins the lateral surfaces of the bladder for some distance.
The bladder is divided into an apex, a body, a fundus and a neck (the part of the bladder that passes into the urethra). The bladder has well-defined muscular and submucosal layers, as a result of which the mucous membrane forms folds. In the area of the bottom of the bladder, there are no folds or submucosal layer; a triangular platform is formed here, in the front part of which the internal opening of the urethra is located. At the base of the triangle there is a fold connecting the orifices of both ureters. The involuntary sphincter of the bladder covers the initial part of the urethra, the voluntary sphincter is located at the level of the membranous part of the urethra.
The blood supply to the bladder is carried out by the superior artery, coming from the umbilical artery, and the lower, coming directly from the anterior trunk of the internal iliac artery.
The veins of the bladder form plexuses in the wall and on the surface of the bladder. They drain into the internal iliac vein. The outflow of lymph is carried out into the lymph nodes located along the vessels.
The innervation of the bladder involves the superior and inferior hypogastric nerve plexuses, pelvic splanchnic nerves and the pudendal nerve.
Prostate
It is located in the subperitoneal section of the small pelvis and covers the initial part of the urethra with its lobes. The prostate has a well-defined fascial capsule, from which ligaments extend to the pubic bones. The gland has two lobes and an isthmus (third lobe). The ducts of the prostate open into the prostatic part of the urethra.
Blood supply to the prostate is carried out by branches from the inferior cystic arteries and middle rectal arteries (from the internal iliac artery). The veins form the prostatic venous plexus, which merges with the vesical plexus and drains into the internal iliac vein.
The pelvic part of the vas deferens is located in the subperitoneal section of the small pelvis and is directed from the internal opening of the inguinal canal downward and posteriorly, forming the ampulla of the vas deferens. Posterior to the ampullae are the seminal vesicles. The duct of the ampulla, merging with the duct of the seminal vesicle, penetrates the body of the prostate and opens into the prostatic part of the urethra. The vas deferens are supplied with blood through the arteries of the vas deferens.
D. N. Lubotsky
24.1. Total information
In descriptive anatomy, the name “pelvis” refers to that part of the body that is bounded by the bones of the pelvic ring. Its upper part is formed by the iliac bones and makes up the large pelvis, in which the abdominal organs are located: in the right iliac fossa there is the cecum with the terminal ileum and the vermiform appendix, in the left iliac fossa there is the sigmoid colon. Below the border line (linea terminalis) the small pelvis begins. The study of the relationships of the pelvic organs is the subject of topographic anatomy. In the following presentation, the small pelvis will be called “pelvis” for brevity.
The soft tissues covering the pelvic bones from the outside are usually classified as other areas: for example, mm. glutei, terminal sections mm. piriformis and obturatorius internus belong to the gluteal region, the terminal section of m. iliopsoas and the initial section of m. obturatorius externus - to the deep parts of the anterior thigh. The outlet from the pelvis is closed soft tissues, making up the perineum.
External landmarks related to the pelvis and perineum have already been described when describing the topography of other areas. Here we should, in addition, note the lower edge of the symphysis and the pubic arch, which can be felt in men behind the root of the scrotum. In women, the lower edge of the pubic fusion, as well as the pelvic promontory (promontorium), is determined during vaginal examination.
Determination of the configuration and condition of the pelvic organs is carried out from the rectum index finger with the right hand inserted into the anus, and in women - also from the vaginal side with the index and middle fingers and at the same time with the left hand through the anterior abdominal wall (the so-called two-handed, bimanual examination).
24.2. Osseous-ligamentous base,
muscles of the walls and floor of the pelvis
The bony basis of the pelvis consists of two pelvic bones, the sacrum, the coccyx and the V lumbar vertebra. Each pelvic bone consists of the ilium, ischium and pubis. The ilia and the sacrum form two low-moving sacroiliac joints; The pubic bones are connected to each other in front motionlessly by fibrocartilage (symphysis ossium pubis; sumphysis pubica - PNA). The bones of the pelvis as a whole articulate with their acetabulums femurs(hip joints).
Two powerful ligaments connect the sacrum (on each side) with the ilium and ischium: lig. sacrospinale and lig. sacrotuberale. Both ligaments and ischiums
Rice. 24.1. Female pelvic diaphragm (according to Lipmann, with modifications):
1 - diaphragma urogenitale; 2 - vasa obturatoria and n. obturatorius; 3 - m. obturatorius internus; 4 - arcus tendineus m. levatoris ani; 5- m. levator ani; 6- anus; 7- vasa glutea superiora and n. gluteus superior; 8- nn. ishiadicus and cutaneus femoris; posterior, vasa glutea inferiora and n. gluteus inferior, vasa pudenda interna and n. pudendus; 9- m. piriformis; 10 - m. coccygeus; 11 - lig. anococcygeum; 12- centrum perineale; 13 - vagina; 14- urethra
The sciatic spine turns the two notches on the pelvic bone into two openings - the greater and lesser sciatic foramina, through which muscles, vessels and nerves pass.
The pelvic walls, in addition to bones, include parietal muscles, a significant part of which belongs to the gluteal region.
The piriformis muscle (m. piriformis) begins from the anterior surface of the sacrum, which passes through the greater sciatic foramen. Above and below the muscle there are slit-like openings (foramen supra-et infrapiriforme), through which vessels and nerves pass.
From the edges of the obturator foramen, on the inner surface of the pelvic bone, m begins. obturatorius internus; this muscle passes through the lesser sciatic foramen. In the pelvis there is an internal (visceral) group of muscles that are directly related to the insides of the pelvis. This is primarily a paired muscle that lifts the anus (m. levator ani) and the external sphincter of the anus (m. sphincter ani externus). M. levator ani has a triangular shape and is made up of two muscles: the anterior (m. pubococcygeus) and the posterior (m. Shosos-cygeus). Both of them start from the inner surface of the pelvic bones (the first - from the pubic bone, the second - from the ilium), as well as from the thickened part of the pelvic fascia (arcus tendineus fasciae pelvis). The fibers of the right and left muscles - the levator ani - form a kind of funnel, tapering downwards. These fibers are located on the sides of the genitourinary system
Rice. 24.2. Male genitourinary diaphragm (according to Callender, with modifications): 1 - symphysis publica; 2 - lig. arcuatum pubis; 3 - v. dorsalis penis; 4 - p. and a. dorsalis penis; 5 - lig. transversum perinei (cut off from above to show the position of the neurovascular bundles); 6, 11 - m. transversus perinei profundus; 7, 12 - fascia diaphragmatis urogenitalis interior; 8 - fascia diaphragmatis urogenitalis superior; 9 - urethra, etc. sphincter urethrae (memoranaceae - BNA); 10 - glandula bulbourethralis (Cowperi)
and partly intertwine with the muscles of the rectum and other pelvic organs, partly they cover the rectum from behind and are attached to the coccyx by means of lig. anococ-cygeum.
Pelvic diaphragm. The muscles that form the floor of the pelvic cavity, together with their fascia, form the so-called pelvic diaphragm. This includes both muscles that lift the anus and the coccygeal muscles located posterior to them (mm. coccygei) (Fig. 24.1).
Urogenital diaphragm. The anterior parts of the levator ani muscles do not close with their inner edges; in the space between them under the pubic arch there is the so-called urogenital diaphragm (diaphragma urogenitale). This name refers to a dense muscular-fascial plate, consisting of the deep transverse perineal muscle and two fascial sheets covering the muscle above and below (Fig. 24.2).
The deep transverse muscle of the perineum performs the angle formed by the lower branches of the pubic and ischial bones. The muscle, however, does not reach the pubic fusion and is separated from it by two ligaments. One of them is lig. transversum perinei - formed by both fascial plates that cover the muscle on both sides and converge anterior to it; the other is lig. arcuatum pubis - runs along the lower edge of the symphysis. Between both ligaments passes the dorsal vein of the penis or clitoris in women (Fig. 24.3).
The urethra passes through the urogenital diaphragm in men, and the urethra and vagina in women. The final section of the rectum passes through the pelvic diaphragm.
24.3. Fascia of the pelvis
The walls and insides of the pelvis are covered with pelvic fascia (fascia pelvis). It is a continuation of the splanchnic fascia of the abdomen and, by analogy with it, is called the splanchnic fascia of the pelvis (fascia endopelvina). It is customary to distinguish between two layers of the pelvic fascia - parietal and visceral. The first lines the walls and bottom of the pelvic cavity, the second covers the pelvic organs (see Fig. 24.3).
At the border of the upper and lower halves of the obturator internus muscle, the parietal layer of the pelvic fascia forms a thickening - a tendon arch (arcus tendineus fasciae pelvis). m starts from it. levator ani, the upper surface of which is covered by the pelvic fascia. In the posterior part of the pelvic floor, the fascia covers the so-called piriformis.
Between the symphysis and the prostate gland in men (or between the symphysis and the bladder in women), the pelvic fascia forms two thick sagittally directed folds or ligaments - ligamenta puboprostatica (ligamenta pubovesicalia - in women).
Moving on to the organs, the pelvic fascia gives off two spurs located in the sagittal plane between the pubic bones and the sacrum. Thus, the pelvic organs find themselves enclosed in a space limited in front by the pubic bones, behind by the sacrum and coccyx, and on the sides by the sagittal plates of the pelvic fascia. This space is divided into two sections - anterior and posterior - by a special septum located in the frontal plane between the bottom of the peritoneal sac and the urogenital diaphragm. The septum is formed by the peritoneal-perineal aponeurosis (aponeurosis peritoneoperinealis), otherwise Denonvilliers aponeurosis 1, representing a duplication of the primary peritoneum. The peritoneal-perineal aponeurosis separates the rectum from the bladder and prostate gland, so that the anterior part of the space in men contains the bladder, prostate gland, seminal vesicles and ampullae of the vas deferens, and in women - the bladder and vagina; the posterior section contains the rectum. Due to the pelvic fascia and Denonvilliers aponeurosis, all of these organs receive fascial sheaths, with particular emphasis on the Pirogov-Retius capsule for the prostate gland and the Amusse capsule for the rectum.
Occupying a middle position in the small pelvis, the organs do not directly touch the walls of the pelvis anywhere and are separated from them by fiber. Where these organs are deprived of peritoneal cover, they are covered by a visceral layer of the pelvic fascia, but between the fascia and the organ there is fiber containing blood and lymphatic vessels and nerves of the organ. Us. 652 the main cellular spaces surrounding the pelvic organs are considered.
24.4. The relationship of the peritoneum to the pelvic organs
Moving to the anterior abdominal wall to the anterior and upper walls of the bladder, the peritoneum forms a transverse vesical fold (plioca vesicalis transver-
1 The Denonvilliers aponeurosis, consisting of two leaves, is also called the rectovesical fascia (fascia rectovesicalis), or septum (septum rectovesicale), in men and the rectovaginal fascia, or septum (fascia rectovaginalis, s. septum rectovaginale), in women. According to L.P. Kraiselburd, the Denonvilliers aponeurosis ends on the posterior wall of the rectum.
sa), located closer to the symphysis when the bladder is empty. Further, in men, the peritoneum covers part of the lateral and posterior walls of the bladder, the inner edges of the ampullae of the vas deferens and the apex of the seminal vesicles (the peritoneum is 1.0-1.5 cm from the base of the prostate gland). Then the peritoneum passes to the rectum, forming the rectovesical space, or notch, excavatio rectovesicalis. On the sides, this recess is limited by the rectovesical folds of the peritoneum (plica rectovesicales), located in the anteroposterior direction from the bladder to the rectum. They contain fibrous and smooth muscle fibers, partly reaching the sacrum.
Part of the loops can be placed in the rectovesical notch small intestine, sometimes transverse or sigmoid colon. It should be noted, however, that the deepest part of the rectovesical space is a narrow slit; Intestinal loops usually do not penetrate into this gap, but effusions can accumulate in it.
At medium degree When filling the bladder, the bottom of the rectovesical space in men is located at the level of the sacrococcygeal joint and is separated from the anus by an average of 6 cm 1 .
In women, during the transition of the peritoneum from the bladder to the uterus, and then to the rectum, two peritoneal spaces (excavations) are formed: the anterior one - excavatio vesicouterina (vesicouterine space) and the posterior one - excavatio rectoute-rina (rectouterine space) 2.
During the transition from the uterus to the rectum, the peritoneum forms two lateral folds that stretch in the anteroposterior direction and reach the sacrum. They are called rectal-uterine folds (plicae rectouterinae) and contain ligaments consisting of muscular-fibrous bundles (m. rectouterinus).
The greater omentum can be placed in the vesicouterine space; in the rectal-uterine space, with the exception of its narrow part, there are loops of small intestines. At the bottom of the excavatio rectouterina, blood, pus, and urine can accumulate during injuries and inflammation; it can be penetrated (for example, by puncture) from the posterior vaginal fornix.
24.5. Three sections of the pelvic cavity
The pelvic cavity is divided into three sections, or floors: cavum pelvis peritoneale, cavum pelvis subperitoneale and cavum pelvis subcutaneum (Fig. 24.5).
The first section - cavum pelvis peritoneale - is the lower part abdominal cavity and is limited (conditionally) from above by a plane passing through the pelvic entrance. It contains those organs or parts of the pelvic organs that are covered by the peritoneum. In men, the peritoneal cavity of the pelvis contains the peritoneal part of the rectum, and then the upper, partially posterolateral and, to a small extent, the anterior walls of the bladder.
In women, the first floor of the pelvic cavity contains the same parts of the bladder and rectum as in men, most of the uterus and its appendages (ovaries and fallopian tubes), wide uterine ligaments, as well as the uppermost section of the vagina (for 1 -2 cm).
1 If there is a collection of pus or blood in this space, it can be emptied
stake through the rectum.
2 This space is also called Douglas space. In gynecology, often both spaces
called Douglas: vesicouterine - anterior Douglas, rectal uterine -
posterior pouch of Douglas.
Rice. 24.5. Three floors of the pelvic cavity (diagram of a frontal incision through the rectum):
1 - cavum pelvis peritoneale; 2 - cavum pelvis subperitoneale; 3 - cavum pelvis subcutaneum (resp. fossa ischiorectalis); 4 - fascia obturatoria and the canalis pudendalis formed by it, containing vasa pudenda interna and n. pudendus; 5- m. levatorani with sheets of pelvic fascia covering the muscle; 6- t. obturatorius interims; 7-peritoneum
The second section - cavum pelvis subperitoneale - is enclosed between the peritoneum and the layer of pelvic fascia covering m. levator ani from above (see Fig. 24.5). Here in men there are the extraperitoneal sections of the bladder and rectum, the prostate gland, seminal vesicles, the pelvic sections of the vas deferens with their ampoules, and the pelvic sections of the ureters.
In women, in this floor of the pelvic cavity there are the same sections of the ureters, bladder and rectum as in men, the cervix, and the initial section of the vagina (with the exception of a small area covered by the peritoneum) 1. The organs located in the cavum pelvis subperitoneale are surrounded by connective tissue sheaths formed by the pelvic fascia (see p. 648).
In addition to the listed organs, in the layer of fiber between the peritoneum and the pelvic fascia there are blood vessels, nerves, lymph nodes.
The third section - cavum pelvis subcutaneum - is enclosed between the lower surface of the pelvic diaphragm and the integument. This section belongs to the perineum and contains parts of the organs of the genitourinary system and the final section of the intestinal tube. This also includes the fat-filled fossa ischiorectalis, located on the side of the perineal section of the rectum (see Fig. 24.5).
1 Part of the subperitoneal space of the pelvis (cavum pelvis subperitoneale), enclosed between the rectum and m. levator ani, in surgery and gynecology is often referred to as cavum pelvirectale(pelvirectal space).
24.6. Vessels, nerves and lymph nodes of the pelvis
The internal iliac artery (a. iliaca interna), otherwise the hypogastric artery (a. hypogastrica - BNA), arises from the common iliac at the level of the sacroiliac joint and is directed downward, outward and posteriorly, located on the posterolateral wall of the pelvic cavity. The accompanying vein passes posterior to the artery. The trunk of the artery is usually short (3-4 cm) and at the level of the upper edge of the greater sciatic foramen is divided into two large branches - anterior and posterior, from which the parietal and visceral arteries arise. The first go to the walls of the pelvis, the second - to the pelvic viscera and external genitalia. From the posterior branch of a. iliaca interna arise only from the parietal arteries, from the anterior - mainly visceral ones.
Parietal veins accompany arteries in the form of paired vessels, visceral veins form massive venous plexuses around organs: pi. venosus rectalis (pi. haemorrhoidalis - BNA), pi. venosus vesicalis, pi. venosus prostaticus (pi. pudendalis - BNA), pi. venosus uterinus, pi. venosus vaginalis. Blood from these plexuses flows into the internal iliac vein and partially (from the rectum) into the portal vein system.
The sacral nerve plexus (plexus sacralis) lies directly on the piriformis muscle. It is formed by the anterior branches of the IV and V lumbar nerves and the I, II, III sacral nerves, emerging through the anterior sacral foramina (see Fig. 23.5). The nerves arising from the plexus, with the exception of short muscle branches, are directed to the gluteal region through the foramen suprapiri- forme (n. gluteus superior with vessels of the same name) and foramen mfrapiriforme (n. gluteus inferior with vessels of the same name, as well as n. cutaneus femoris posterior, n. ischiadicus). Together with the last nerves, the n. pudendus emerges from the pelvic cavity, accompanied by vessels (vasa pudenda interna). This nerve arises from the plexus pudendus, which lies at the lower edge of the piriformis muscle (under the sacral plexus) and is formed by the II, III and IV sacral nerves. Along the lateral wall of the pelvis, below the boundary line, passes the obturatorius (from the lumbar plexus), which, together with the vessels of the same name, penetrates the canalis obturatorius and through it into the bed of the conductive muscles of the thigh (see Fig. 23.5).
Along the inner edge of the anterior sacral foramina lies the sacral section of the sympathetic trunk, and outward from it extend the anterior branches of the sacral nerves, forming the sacral plexus (see Fig. 23.5).
The main sources of innervation of the pelvic organs are the right and left trunks of the sympathetic nerve (their branches are called nn. hypogastrici dexter et sinister) and the II, III and IV sacral nerves, which provide parasympathetic innervation (their branches are called nn. splanchnici pelvini, otherwise - nn. erigentes ) (see Fig. 24.16). The branches of the sympathetic trunks and branches of the sacral nerves, as a rule, do not directly participate in the innervation of the pelvic organs, but are part of the hypogastric plexuses, from where secondary plexuses arise that innervate the pelvic organs.
There are three groups of lymph nodes in the pelvis: one group is located along the external and common iliac arteries, the other along the internal iliac artery, and the third on the anterior concave surface of the sacrum. The first group of nodes receives lymph from the lower limb, superficial vessels of the gluteal region, abdominal walls (their lower half), superficial layers of the perineum, and from the external genitalia. The internal iliac nodes collect lymph from most of the pelvic organs and structures that make up the pelvic wall. The sacral nodes receive lymph from the posterior wall of the pelvis and from the rectum.
The node lying in the bifurcation of the common iliac artery is designated as lymphonodus interiliacus. It contains two lymph flows from the pelvic organs and from the lower limb.
The related vessels of the iliac nodes are directed to the nodes lying at the inferior vena cava (right) and the aorta (left). Some of these vessels are interrupted in the so-called subaortic nodes, which lie at the level of the aortic bifurcation near the right and left common iliac arteries.
In both the male and female pelvis, there are direct and indirect connections between the abducens lymphatic vessels various organs.
24.7. Cellular spaces of the pelvis
The pelvic tissue separates the organs contained in it from the walls of the pelvis and is also enclosed between the organs and the fascial sheaths surrounding them. The main cellular spaces of the pelvic cavity are located in the middle floor of its cavum subperitoneale (see Fig. 21.34, 21.35).
In the lateral sections of the pelvis, on both sides of the parietal leaf of the pelvic fascia, there is fiber of the parietal space, and outside the parietal leaf there are large nerve trunks that form the sacral plexus, and inside there are large vessels (internal iliac). This fiber also accompanies blood vessels and nerves heading to internal organs pelvis and to neighboring areas: through the foramen infrapiriforme, along the lower gluteal vessels and nerve, it has a connection with the fiber of the gluteal region, and further along the sciatic nerve - with the fiber of the posterior thigh. Through the canalis obturatorius, the parietal space of the pelvis communicates with the fiber of the bed of the adductor muscles of the thigh.
Behind the symphysis and anterior to the bladder there is a practically important prevesical space (spatium prevesicale), often called the rettian space, and according to BNA - spatium retropubicum (retropubic space). It is bounded below by the puboprostatic (or pubovesical) ligaments. It should be emphasized that anterior to the bladder there is not one cellular space, but two: prevesical and preperitoneal. The presence of two spaces is due to the existence of a special fascia - prevesical, covering the anterior surface of the bladder. The fascia has the form of a triangular plate, the lateral edges of which reach the obliterated umbilical arteries, and the apex ends in the area of the umbilical ring. Thus, between the transverse fascia of the abdomen, attached to the upper edge of the symphysis, and the prevesical fascia, the prevesical space is formed, and between the prevesical fascia and the peritoneum, the preperitoneal space of the bladder (see Fig. 24.18).
Hematomas may develop in the prevesical space during pelvic fractures; In case of damage to the bladder, urinary infiltration may occur here. Since extraperitoneal rupture of the bladder disrupts the integrity of the prevesical fascia, urinary infiltration spreads upward along the preperitoneal tissue of the anterior abdominal wall (see Fig. 21.45).
From the sides, the prevesical space passes into the paravesical space (spatium par-avesicale), reaching the internal iliac vessels (Fig. 24.6).
If the integrity of the prevesical fascia near the internal iliac vessels is violated, the purulent process from the peri-vesical space can spread into the tissue of the parietal space of the pelvis, and from there into the retroperitoneal tissue of the iliac fossa.
The posterior rectal tissue space (spatium retrorectale) is located behind the ampulla of the rectum and its capsule, at the back it is limited by the sacral bone, and at the bottom by the fascia covering the m. levator
In the female pelvis, the blood supply, innervation and peritoneal coverage of the rectum are the same as in the male pelvis. Anterior to the rectum are the uterus and vagina. Posterior to the rectum lies the sacrum. Lymphatic vessels of the rectum are associated with lymphatic system uterus and vagina (in the hypogastric and sacral lymph nodes) (Fig. 16.4).
Bladder in women, as in men, it lies behind the pubic symphysis. Behind the bladder are the uterus and vagina. The loops of the small intestine are adjacent to the upper part of the bladder, covered with peritoneum. On the sides of the bladder are the levator ani muscles. The bottom of the bladder lies on the urogenital diaphragm. The blood supply and innervation of the bladder in women occurs in the same way as in men. The lymphatic vessels of the bladder in women, like the lymphatic vessels of the rectum, form connections with the lymphatic vessels of the uterus and vagina in the lymph nodes of the broad ligament of the uterus and the iliac lymph nodes.
As in the male pelvis, the right and left ureters at the level of the boundary line cross the external iliac and common iliac arteries, respectively. They are adjacent to the lateral walls of the pelvis. At the point where the uterine arteries depart from the internal iliac arteries, the ureters intersect with the latter. Lower in the cervix, they once again intersect with the uterine arteries, and then adhere to the vaginal wall, after which they empty into the bladder.
Rice. 16.4. Topography of the female pelvic organs (from: Kovanov V.V., ed., 1987): I - fallopian tube; 2 - ovary; 3 - uterus; 4 - rectum; 5 - posterior vaginal fornix; 6 - anterior vaginal vault; 7 - entrance to the vagina; 8 - urethra; 9 - clitoris; 10 - pubic joint; II - bladder
Uterus in the pelvis of women, it occupies a position between the bladder and the rectum and is tilted forward (anteversio), while the body and cervix, separated by the isthmus, form an angle open anteriorly (anteflexio). The loops of the small intestine are adjacent to the fundus of the uterus. The uterus has two sections: the body and the cervix. The part of the body located above the confluence of the fallopian tubes into the uterus is called the fundus. The peritoneum, covering the uterus in front and behind, converges on the sides of the uterus, forming the broad ligaments of the uterus. The uterine arteries are located at the base of the broad ligament of the uterus. Next to them lie the main ligaments of the uterus. The fallopian tubes lie in the free edge of the broad ligaments of the uterus. The ovaries are also attached to the broad ligaments of the uterus. On the sides, the broad ligaments pass into the peritoneum, covering the walls of the pelvis. There are also round ligaments of the uterus, running from the angle of the uterus to the internal opening of the inguinal canal. The uterus is supplied with blood by two uterine arteries from the system of internal iliac arteries, as well as ovarian arteries - branches of the abdominal aorta. Venous drainage occurs through the uterine veins into the internal iliac veins. The uterus is innervated from the hypogastric plexus. Lymph flows from the cervix to the lymph nodes located along the iliac arteries and sacral lymph nodes, from the body of the uterus to the peri-aortic lymph nodes.
The uterine appendages include the ovaries and fallopian tubes.
The fallopian tubes lie between the leaves of the broad ligaments of the uterus along their upper edge. In the fallopian tube, there is an interstitial part located in the thickness of the uterine wall, an isthmus (narrowed part of the tube), which passes into an expanded section - the ampulla. At the free end, the fallopian tube has a funnel with fimbriae, which is adjacent to the ovary.
Ovaries with the help of the mesentery they are connected to the posterior leaves of the broad ligament of the uterus. The ovaries have uterine and tubal ends. The uterine end is connected to the uterus by its own ovarian ligament. The tubal end is attached to the lateral wall of the pelvis by the suspensory ligament of the ovary. In this case, the ovaries themselves are located in the ovarian fossae - depressions in the side wall of the pelvis. These depressions are located in the area where the common iliac arteries divide into internal and external. The uterine arteries and ureters lie nearby, which should be taken into account when performing operations on the uterine appendages.
Vagina located in the female pelvis between the bladder and rectum. At the top, the vagina passes into the cervix, and at the bottom
opens with an opening between the labia minora. The anterior wall of the vagina is closely connected to the posterior wall of the bladder and the urethra. Therefore, when the vagina ruptures, vesicovaginal fistulas can form. The posterior wall of the vagina is in contact with the rectum. At the vagina, there are fornices - indentations between the cervix and the walls of the vagina. In this case, the posterior fornix borders on the pouch of Douglas, which allows access to the rectouterine cavity through the posterior vaginal fornix.
The pelvis is a collection of bones and soft tissues located below the boundary line.
The walls of the pelvis, represented by the pelvic bones below the boundary line, the sacrum, the coccyx and the muscles that close the greater sciatic (piriformis) and obturator (obturator internus) openings, limit the pelvic cavity in front, behind and on the sides. From below, the pelvic cavity is limited by the soft tissues of the perineum. Its muscular basis is formed by the levator ani muscle and the deep transverse perineal muscle, which take part in the formation of the pelvic diaphragm and the genitourinary diaphragm, respectively.
The pelvic cavity is usually divided into three sections, or floors:
Peritoneal cavity of the pelvis– the upper section of the pelvic cavity, enclosed between the parietal peritoneum of the small pelvis (is the lower section of the abdominal cavity). Contains the peritoneal parts of the pelvic organs - the rectum, bladder, in women - the uterus, wide uterine ligaments, fallopian tubes, ovaries and the upper part of the posterior wall of the vagina. After emptying the pelvic organs, loops of the small intestine, the greater omentum, and sometimes the transverse or sigmoid colon and the vermiform appendix can descend into the peritoneal cavity of the pelvis.
Subperitoneal cavity of the pelvis– department of the pelvic cavity,
enclosed between the parietal peritoneum and the leaf of the pelvic fascia, which covers the levator ani muscle on top. Contains blood and lymphatic vessels, lymph nodes, nerves, extraperitoneal parts of the pelvic organs - bladder, rectum, pelvic part of the ureter. In addition, in the subperitoneal cavity of the pelvis in women there are the vagina (except for the upper part of the posterior wall) and the cervix, in men - the prostate gland, the pelvic parts of the vas deferens, the seminal
new bubbles. The listed organs are surrounded by fatty tissue, divided by spurs of the pelvic fascia into several cellular spaces.
Subcutaneous pelvic cavity- the space related to the perineum and lying between the skin and the pelvic diaphragm. It contains the ischiorectal fossa filled with fatty tissue with the internal genital vessels and the pudendal nerve passing through it, as well as their branches, parts of the organs of the genitourinary system, and the distal part of the rectum. The outlet from the small pelvis is closed by the pelvic and genitourinary diaphragms, formed by muscles and fascia.
Course of the peritoneum
In the cavity of the male pelvis, the peritoneum passes from the anterolateral wall of the abdomen to the anterior wall of the bladder, covers its upper, posterior and part of the side walls and passes to the anterior wall of the rectum, forming the rectovesical cavity. From the sides it is limited by the rectovesical folds of the peritoneum. This recess can accommodate part of the loops of the small intestine and the sigmoid colon.
In women, the peritoneum passes from the bladder to the uterus (covers mesoperitoneally), then to the posterior fornix of the vagina, and then to the anterior wall of the rectum. Thus, two depressions are formed in the cavity of the female pelvis: the vesico-uterine and the rectal-uterine. During the transition from the uterus to the rectum, the peritoneum forms two folds that stretch in the anteroposterior direction, reaching the sacrum. The greater omentum may be located in the vesicouterine recess; in the rectal-uterine - loops of the small intestine. Blood, pus, and urine can also accumulate here during injuries and inflammation.
Fascia of the pelvis
The pelvic fascia is a continuation of the intra-abdominal fascia and consists of parietal and visceral layers.
The parietal layer of the pelvic fascia covers the parietal muscles of the pelvic cavity and is divided into the upper fascia of the genitourinary and pelvic diaphragm and the lower fascia of the genitourinary
howl and pelvic diaphragm, which contain the muscles that form the pelvic floor (the deep transverse muscle of the perineum and the levator ani muscle).
The visceral layer of the pelvic fascia covers the organs located in the middle floor of the small pelvis. This leaf forms fascial capsules for the pelvic organs (Pirogov-Retsia for the prostate gland and Amousse for the rectum), separated from the organs by a layer of loose fiber in which blood and lymphatic vessels and nerves of the pelvic organs are located. The capsules are separated by a septum located in the frontal plane (Denonvillier-Salischev aponeurosis; rectovesical septum in men and rectovaginal septum in women), which is a duplicate of the primary peritoneum. Anterior to the septum are the bladder, prostate gland, seminal vesicles and parts of the vas deferens in men, and the bladder and uterus in women. Posterior to the septum is the rectum.
Cellular spaces of the pelvis Classification:
1. Parietal: retropubic (preperitoneal, prevesical), retrovesical, retrorectal, parametric, lateral.
2. Visceral: peri-vesical, peri-rectal, periocervical.
Lateral cellular space– paired (right-, and
left-sided), laterally limited by the parietal fascia of the pelvis, medially by the sagittal spurs of the visceral fascia of the pelvis.
Content: internal iliac vessels and their branches, pelvic parts of the ureters, vas deferens, branches of the sacral plexus.
Ways of spread of pus:
l into the retrovesical space (along the ureter);
l into the retroperitoneal space (along the ureter);
l in the gluteal region (along the course of the upper and lower gluteal vessels and nerves);
l into the inguinal canal (along the vas deferens).
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Retropubic space
1. Prevesical space -limited to the front of the forehead-
by the symphysis and branches of the pubic bones, and posteriorly by the prevesical fascia.
2. Preperitoneal space – between the prevesical fascia and the anterior layer of the visceral fascia of the bladder.
Ways of spread of pus:
l into the subcutaneous fatty tissue of the thigh (through the femoral ring);
l into the tissue surrounding the medial group of thigh muscles (through the obturator canal);
l into the preperitoneal tissue of the anterior abdominal wall;
l into the lateral cellular space of the pelvis (through defects in the sagittal spurs of the visceral fascia of the pelvis).
Paravesical space-located between the walls-
of the bladder and the visceral fascia covering it.
Content: vesical venous plexus.
Posteriorvesical space–limited front to rear-
nim layer of the visceral fascia of the bladder, posteriorly
– the peritoneal-perineal fascia, forming the recto-vesical septum in men or the rect-vaginal septum in women.
Content: in men – the prostate gland, seminal vesicles, vas deferens and ureters; in women - the vagina and ureters.
Ways of spread of pus:
l into the groin area and scrotum (along the vas deferens through the inguinal canal);
l into the retroperitoneal cellular space (along the ureters).
Posterior rectal space–limited specialization
between the rectum, covered with the visceral fascia of the pelvis; behind - the sacrum, lined with the parietal fascia of the pelvis.
Content: sacral parts of the sympathetic trunks, sacral lymph nodes, lateral and median sacral arteries, veins of the same name forming the sacral
venous plexus, superior rectal artery and vein.
Ways of spread of pus(along the course of the vessels) :
l into the retroperitoneal space;
l into the lateral cellular space of the pelvis.
Pararectal space-between visceral-
the fascia of the pelvis, covering the rectum, and its wall.
Circumferential (parametric) space – steam-
new ( right- and left-sided), between the leaves of the broad uterine ligaments .
Ways of spread of pus:
l laterally and downwards - into the lateral space of the pelvis;
l medially and downwards - into the pericervical tissue;
l into the retrovesical space.
Pericervical space - located around the cervix of the uterus.
Pelvic vessels
The walls and organs of the pelvis are supplied with blood by the internal iliac arteries, which enter the lateral cellular spaces and are divided into anterior and posterior branches. Branches depart from the anterior branches of the internal iliac arteries that supply blood primarily to the pelvic organs:
the umbilical artery, which gives off the superior vesical artery;
inferior vesical artery; uterine artery – among women, in men– spermatic artery
efferent duct; middle rectal artery;
internal pudendal artery.
From posterior branches internal iliac arteries drain-
branches supplying blood to the walls of the pelvis:
iliopsoas artery; lateral sacral artery; obturator artery; superior gluteal artery;
inferior gluteal artery.
The parietal branches of the internal iliac arteries are accompanied by two veins of the same name. Visceral veins form well-defined venous plexuses around organs. The venous plexus of the bladder, prostate, uterus, vagina and rectum is distinguished. The veins of the rectum, in particular the superior rectal vein, flow through the inferior mesenteric vein into the portal vein, the middle and inferior rectal veins into the inferior vena cava system. They are connected to each other, forming portocaval anastomoses. From other venous plexuses, blood flows into the inferior vena cava system.
Innervation of the pelvis Sacral plexus(somatic, paired) formed
anterior branches of the IV, V lumbar and I, II, III sacral spinal nerves.
Branches:
muscle branches; superior gluteal nerve;
inferior gluteal nerve; posterior cutaneous nerve of the thigh; sciatic nerve; pudendal nerve
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The main differences between the female pelvis and the male pelvis are clearly visible in adults. The main ones are the following: the bones of the female pelvis, compared to the male, are thinner and smoother; the female pelvis is lower, more voluminous and wider, the wings of the iliac bones in women are deployed more strongly, as a result of which the transverse dimensions of the female pelvis more sizes male; the entrance to the woman’s pelvis is wider and does not narrow downwards in a funnel-shaped manner, as in men, but, on the contrary, widens; as a result, the outlet from the pelvis of women is wider than that of men; the angle formed by the lower branches of the pubic bones of the pelvis in women is more obtuse (90-100 degrees) than in men (70-75 degrees). Thus, the pelvis adult woman Compared to men's, it is more voluminous and wide, and at the same time less deep.
All joints of the pelvic bones are immobile or weakly mobile; during pregnancy they soften, and by the end of pregnancy they become so extensible that the pelvic bones, to a certain extent, become mobile in relation to each other; This is most pronounced in the sacrococcygeal joint.
Particularly important during childbirth is the pelvic floor of the female pelvis, which is included in the birth canal and promotes the birth of the fetus.
The superior aperture of the small pelvis - or the entrance to the pelvic cavity is limited by the border line, the promontory of the sacrum. The subpubic angle, the ischial tuberosities, the sacrotubercular ligaments, the apex of the sacrum and the coccyx delimit the inferior pelvic aperture (or the entrance to the pelvic cavity). The planes of entry and exit, as well as the so-called “wide part of the pelvis”, are of particular importance in obstetric practice; they are assessed by direct and transverse, right and left oblique dimensions.
The direct size of the entrance - between the upper edge of the symphysis and the promontory is 11 cm; oblique size - from the pubic-crestal eminence to the sacroiliac joint - 12 cm; the direct size of the exit between the pubic angle and the coccyx is 9.5 cm; transverse between the ischial tuberosities - 11 cm; the transverse and straight dimensions of the pelvic cavity are 1-3 cm larger than the dimensions of the inlet; the line connecting the middle of the straight dimensions and the pelvic cavity is its axis (wire line in obstetrics). The entrance plane is inclined anteriorly and forms an angle of 54-55 degrees with the horizontal plane (inclination angle).
The lower wall is located at the outlet of the pelvis and belongs to the layers of the perineum, the deep muscles of which form the pelvic diaphragm and the genitourinary diaphragm: the levator ani muscle, the deep transverse perineal muscle; the anus passes through the first of them, the urethra and vagina pass through the second.
Rectum
In the female pelvis, anterior to the rectum are the uterus and vagina. In the peritoneal floor of the small pelvis, between the rectum and the uterus, there is the lowest part of the pelvic cavity - the rectal-uterine cavity (excavatio rectouterina), where loops of the small intestine can be located. In the subperitoneal floor, the rectum is adjacent to the vagina. The peritoneal-perineal aponeurosis, or septim rectovaginale, separates the rectum and vagina. The lymphatic vessels of the rectum form connections with the lymphatic vessels of the uterus and vagina.Bladder and ureters
In the female pelvis, the bladder lies deeper in the pelvic cavity than in men. In front it is adjacent to the symphysis and is fixed to it by the pubovesical ligaments. The bottom of the bladder is located on the urogenital diaphragm. Posterior to the bladder is the uterus and in the subperitoneal space the vagina. The lymphatic vessels of the bladder in women form direct connections with the lymphatic vessels of the uterus and vagina at the base of the broad ligament of the uterus and in the regional iliac lymph nodes.In the cavity of the female pelvis, the fascia of the bladder has similar relationships with the fascia of the cervix and vagina; here the most pronounced is the frontally located peritoneal-perineal aponeurosis (Denonvilliers) between the posterior wall of the vagina and the rectum.
The ureters in the female pelvis, as in the male pelvis, are located under the peritoneum and are surrounded by paraurethral tissue and have their own fascial sheath. In the pelvic cavity, the ureters of the sechala lie on the side wall of the pelvis, on the anterior surface of the internal iliac artery, anterior to the uterina, then in the thickness of the base of the broad ligaments of the uterus. Here the ureters are crossed again a. uterina, located under it and 1.5-2 cm from the internal os of the cervix. Further, the ureter is adjacent to the anterior wall of the vagina for a short distance and flows into the bladder at an acute angle.
V. D. Ivanova, A. V. Kolsanov, S.S. Chaplygin, P.P. Yunusov, A.A. Dubinin, I.A. Bardovsky, S. N. Larionova
