Impaired intestinal function,), various inflammatory processes (,), contributing to prolonged irritation of the mucous membrane, lead to the appearance of papillae at the base of the crypts, which are sometimes significantly enlarged. Hypertrophied papillae are mistaken for papillae, while they are just a simple elevation of normal mucosa.

The blood supply to the rectum is provided by the superior, middle and inferior hemorrhoidal arteries. Of these, the first artery is unpaired, and the remaining two are paired, approaching the intestine from the sides. The veins of the rectum go along with the arteries. The outflow of venous blood occurs in two directions - through the portal system and through the vena cava system. In the wall lower section the intestines are located in dense venous plexuses - submucosal and associated subfascial and subcutaneous, located in the area of ​​the sphincter and anal canal.

Before moving on to the physiology of the rectum, let us briefly dwell on the mechanism of formation feces. It is known that in a person, an average of about 4 liters of food gruel (chyme) passes from the small intestines to the large intestines per day. In the large intestine (in the right section - in the cecum and ascending colon), thanks to tonic contractions, peristaltic and antiperistaltic movements, thickening, mixing of intestinal contents and the formation of feces occurs. From 4 liters of chyme, only 140-200 g of formed feces remain in the colon, which usually consists of the remains of digested food (fiber fibers, muscle and tendon fibers, grains covered with fiber, etc.), waste products of the intestine (mucus, exfoliated mucosal cells, cholic acid, etc.), as well as from living and dead bacteria.

The left half of the colon performs an evacuation function, which is facilitated by the so-called large and small movements. Small movements are continuously occurring small contractions that mix the contents of the intestine; large movements are intense, rapid contractions of entire sections that help move the intestinal contents. They occur 3-4 times a day.

Food from the stomach is evacuated on average after 2-2.5 hours. After 6 hours, liquid intestinal contents have traveled 5-6 m small intestine, moves to the large intestine, through which it passes for 12-18 hours. As already mentioned, approximately 4 liters of semi-liquid chyme passes from the small intestine to the large intestine per day. Over 3.7 liters of liquid is absorbed during this time in the large intestine. Together with the liquid, toxic substances enter the bloodstream - products of food breakdown and intestinal fermentation.

Venous blood, saturated with these products, flows through the portal vein system into, where they are retained, neutralized and ejected from. Thus, the colon also has an absorption function.

Bowel movement - the act of defecation - occurs as a result of a complex interaction of a number of physiological mechanisms. By peristaltic movements, the feces gradually move into. The accumulation and retention of feces occurs mainly due to contractions of the circular muscle layer of the intestine.

When feces are lowered into the rectal ampulla, new mechanisms come into motion - reflex tonic contractions of the striated muscles of the external anal sphincter. The act of defecation consists of the following stages: filling the ampoule with feces, evacuation peristalsis of the rectum and sigmoid with reflex relaxation of the sphincters, simultaneous activation of the auxiliary muscle group (abdominals and others). The rectum remains empty for a long time after defecation.

It should be noted that the actions of the auxiliary muscle group, varying in intensity, are aimed at accelerating and enhancing the evacuation of feces, especially in cases of hard consistency or any pathological conditions(constipation, atony,).

The anus and rectum have a rich receptive field; here, when irritated, impulses arise that are transmitted to the stomach and affect its functioning, as well as bile secretion.

Bowel emptying is due to the influence of not only unconditioned (stretching the ampoule), but also to the action of conditioned stimuli that create the usual rhythm of defecation in certain time day. The act of defecation is influenced by the cerebral cortex, which is confirmed by the following fact: sudden mental or physical irritation can completely remove the stool that is already habitual and delay bowel movements for a long time.

As you can see, the main physiological function rectum - the act of defecation - is a complex process in which many mechanisms are involved. Any violation of them leads to a breakdown of this function.

The rectum is the final section of the intestine.

Anatomy
The rectum begins at the level of the II-III sacral vertebrae and descends in front of the sacrum, having an S-shape with an expansion in the middle part (color. Fig. 1). The upper curvature of the rectum is sacral (flexura sacralis) - corresponds to the concavity of the sacrum, the lower - perineal (flexura perinealis) - faces backward. According to the bends on inner surface the intestines form transverse folds (plicae transversales recti) - usually two on the left, one on the right.

In the middle part, the rectum expands, forming an ampulla (ampulla recti). The final section of the rectum - the anal canal (canalis analis) - is directed back and down and ends with the anus (anus). The length of the intestine is 13-16 cm, of which 10-13 cm are in the pelvic region, and 2.5-3 cm are in the perineal region. The circumference of the ampullary part of the intestine is 8-16 cm (with overflow or atony - 30-40 cm).

Clinicians distinguish 5 sections of the rectum: supramullary (or recto-sigmoid), superior ampullary, mid-ampullary, inferior ampullary and perineal.

The walls of the rectum consist of 3 layers: mucous, submucosal and muscular. The upper part of the rectum is covered in front and on the sides with a serous membrane, which in the uppermost part of the intestine surrounds it and behind, passing into the short mesentery (mesorectum). The mucous membrane has a large number of longitudinal folds that can be easily straightened.

Vessels and nerves of the rectum.
Rice. 1. Blood and lymphatic vessels of the rectum (frontal cut of the male pelvis; the peritoneum is partially removed, the mucous membrane of the rectum in its lower part is removed).
Rice. 2. Blood vessels and nerves of the rectum (sagittal section of the male pelvis).
1 - nodi lymphatici mesenterici inf.; 2 - a. et v. rectales sup.; 3 - colon sigraoldeum; 4 - plexus venosus rectalis; 5 - a. et v. rectales raedil sin.; 6 - plica transversa; 7 - nodus lymphaticus iliacus int.; 8 - ra. levator ani; 9 - tunica muscularis (stratum circulare); 10 - muscle bundles in the region of columnae anales; 11 - m. sphincter ani ext.; 12 - m. sphincter ani int.; 13 - anus; 14 - a. et v. rectales inf.; 15 - zona haemorrhoidalis (venous plexus); 16 - a. et v. rectales mediai dext.; 17 - tunica mucosa recti; 18 - rectum; 19 - a. iliaca int.; 20 - v. iliaca int.; 21 - nodus lymphaticus sacralis; 22 - a. sacralis med.; 23 - plexus rectalis sup.; 24 - plexus sacralis; 25 - plexus rectalis med.; 26 - columnae anales; 27 - prostate; 28 - vesica urinaria; 29 - plexus hypogastricus int.; 30 - mesorectum.

In the anal canal there are 8-10 permanent longitudinal folds - columns (columnae anales) with depressions between them - anal sinuses (sinus anales), which end in semilunar folds - valves (valvulae anales). A slightly protruding zigzag line from the anal valves is called anorectal, serrated, or pectinate, and is the boundary between the glandular epithelium of the ampulla and flat epithelium anal canal of the rectum. The annular space between the anal sinuses and the anus is called the hemorrhoidal zone (zona hemorrhoidalis).

The submucosal layer consists of loose connective tissue, which promotes easy displacement and stretching of the mucous membrane. The muscle wall has two layers: the inner - circular and the outer - longitudinal. The first thickens in the upper part of the perineal region to 5-6 mm, forming the internal sphincter (m. sphincter ani int.). In the area of ​​the perineal part of the intestine, longitudinal muscle fibers are intertwined with the fibers of the muscle that lifts the ani (m. levator ani), and partially with the external sphincter. The external sphincter (m. sphincter ani ext.), in contrast to the internal one, consists of voluntary muscles covering the perineal region and closing the rectum. It has a height of about 2 cm and a thickness of up to 8 mm.

The pelvic diaphragm is formed by the muscles that lift the ani and the coccygeus muscle (m. coccygeus), as well as the fascia covering them. The paired muscles that lift the ani consist mainly of the iliococcygeus (m. iliococcygeus), pubococcygeus (m. pubococcygeus) and puborectalis (m. puborectalis) muscles and form a kind of funnel lowered into the pelvis. Its edges are attached to upper sections the inner walls of the small pelvis, and below, in the center of the funnel, the rectum is inserted, as it were, connected to the fibers of the levator ani muscle. The latter divides the pelvic cavity into two sections: upper-internal (pelvic-rectal) and lower-external (ischiorectal). The upper-inner surface of the levator ani muscle is covered with the fascia of the pelvic diaphragm (fascia diaphragmatis pelvis sup.), which connects to the fascia of the rectum.

The peritoneal cover extends only to the upper anterior section of the rectum, descending in front to the pouch of Douglas and rising from the sides to the level of the third sacral vertebra, where both serous layers join to form the initial part of the mesentery.

Attached to the edges of this elongated downward oval of the peritoneal cover is the own fascia of the rectum, which is denser at the back and relatively less pronounced at the sides, and at the front turning into a dense prostatic-peritoneal aponeurosis (in men) or rectovaginal aponeurosis (in women). This aponeurosis is easily divided into two plates, one of which covers the prostate gland with seminal vesicles, and the other covers the anterior wall of the rectum; this makes it easier to separate these organs during surgery. Extrafascial removal of the rectum along with the abducens lymphatic vessels without violating their integrity is considered the most important condition radical surgery.

Blood supply of the rectum (color table, Fig. 1 and 2) is carried out through the unpaired upper rectal artery (a. rectalis sup.) and through two paired - middle and lower - rectal arteries (aa. rectales med. et inf.). The superior rectal artery is the terminal and largest branch of the inferior mesenteric artery. Good vascular network sigmoid colon allows you to maintain its full blood supply, provided that the marginal vessel is left intact even after a high intersection of the superior rectal and one to three inferior sigmoid arteries. The safety of crossing the artery above the “Sudek critical point” can be ensured only by maintaining the integrity of the marginal vessel. The blood supply to the entire rectum to the anal part is carried out mainly by the superior rectal artery, which is divided into two and sometimes more branches at the level of the III-IV sacral vertebrae.

The middle rectal arteries, arising from the branches of the internal iliac artery, are not always equally developed and are often completely absent. However, in some cases they play important role in the blood supply of the rectum.

The inferior rectal arteries, arising from the internal pudendal arteries, supply mainly the external sphincter and the skin of the anal area. There are good anastomoses between the branches of the systems of the upper, middle and lower rectal arteries, and the intersection of the superior rectal artery at different levels while maintaining the integrity of the middle and lower rectal arteries and their numerous nameless branches in the anterior and lateral sections of the rectum, it does not deprive the lower segment of the intestine of nutrition.

The venous plexuses of the rectum (plexus venosi rectales) are located in different layers intestinal wall; There are submucosal, subfascial and subcutaneous plexuses. The submucosal, or internal, plexus is located in the form of a ring of dilated venous trunks and cavities in the submucosa. It is connected with the subfascial and subcutaneous plexuses. Venous blood flows into the portal vein system through the superior rectal vein (v. rectalis sup.) and into the inferior vena cava system through the middle and lower rectal veins (vv. rectales med. et inf.). There are many anastomoses between these systems. The absence of valves in the superior rectal vein, as in the entire portal system, plays an important role in the development of venous stasis and dilation of the veins of the distal segment of the rectum.

Lymphatic system . The lymphatic vessels of the rectum are important because tumors and infections can spread through them.

In the rectal mucosa there is a single-layer network of lymphatic capillaries, connected to a similar network of the submucosal layer, where a plexus of lymphatic vessels of the I, II and III orders is also formed. In the muscular lining of the rectum, a network of lymphatic capillaries is formed, composed of capillaries of the circular and longitudinal layers of the rectum. IN serosa In the rectum there are superficial (finely looped) and deep (broadly looped) networks of lymphatic capillaries and lymphatic vessels.

The draining lymphatic vessels mainly follow the course of blood vessels. There are three groups of extramural lymphatic vessels: upper, middle and lower. The upper lymphatic vessels, collecting lymph from the walls of the rectum, are directed along the branches of the superior rectal artery and flow into the so-called Gerota's lymph nodes. The middle rectal lymphatic vessels run from the lateral walls of the intestine under the fascia covering the levator ani muscle towards the lymph nodes located on the walls of the pelvis. The lower rectal lymphatic vessels originate in the skin of the anus and are connected with the lymphatic vessels of the mucous membrane of the anal canal and ampulla. They go in the thickness of the subcutaneous fatty tissue to the inguinal lymph nodes.

The outflow of lymph, and therefore the transfer of tumor cells, can go in many directions (see below).

The innervation of the rectosigmoid and ampullary parts of the rectum is carried out mainly by the sympathetic and parasympathetic systems, perineal - mainly by branches spinal nerves(color fig. 2). This explains the relatively low sensitivity of the rectal ampulla to pain and the high pain sensitivity of the anal canal. The internal sphincter is innervated by sympathetic fibers, the external sphincter by the branches of the pudendal nerves (nn. pudendi), accompanying the inferior rectal arteries. The levator ani muscle is innervated by branches coming mainly from the III and IV sacral nerves, and sometimes from the rectum. This is important when resection of the lower sacral vertebrae for access to the rectum, as it indicates the need to transect the sacrum below the third sacral foramina in order to avoid serious dysfunction of not only the levator ani muscle and the external sphincter, but also other pelvic organs.

Approximately the same for women and men. But since the intestines are located somewhere in the same area as the genitals, they have their own characteristics and differences.

This article discusses the structure of the organ in men and women, its functions and possible diseases.

More about the rectum

This organ descends to the pelvis, forming curves. One of them is convex forward, and the other protrudes backward, repeating the curve of the sacrum.

The length of the intestine is from 10 to 15 cm. The organ consists of muscle tissue, mucous membrane and submucosal part, located in the connective tissue membrane - in male body it also covers the prostate gland, and in the female it envelops the cervix.

The mucous membrane is covered epithelial tissue, which contains a large number of Lieberkühn crypts (glands).

These glands, in turn, consist of cells that produce mucus, which explains why mucus is secreted from the intestines in various diseases.

Just above the anus are the rectal columns of Morgagni, formed by a fold of mucous tissue. They resemble columns, their number varies from 6 to 14.

Between the columns there are niches called pockets. Quite often they retain fecal residues, which can cause inflammation.

Intestinal diseases and disorders motor function irritate the intestinal mucosa, which is why papillae may appear on it, the size of which depends on how severely the mucosa is irritated. Sometimes the irritation is mistaken for a polyp.

Blood enters the rectum from several hemorrhoidal arteries - from the lower, middle and upper. The first two are paired, but the top one is not.

Blood moves through the veins through the hollow and portal veins; in the lower part of the rectum there are many large venous plexuses.

In women, the structure of the intestine is different from the male body. This is influenced by the characteristics of the female reproductive system.

In women, the rectum is adjacent to the vagina in front - between the organs, of course, there is a separating layer, but it is very thin.

If inflammation occurs in one of these organs, it is likely that it will spread to the neighboring organ.

Because of this internal structure Women quite often develop fistulas that affect both the intestines and the organs of the reproductive system.

This disease is a consequence of problematic childbirth or any trauma.

The rectum is the last part of the intestine that ends with the sphincter. Surprisingly, the anus in men and women has a different structure.

The sphincter or anus is a depression that goes into the rectum. Depending on the structure of the body, it may be located quite deep or not very deep.

In men, for example, the sphincter may be funnel-shaped, while in women it is flatter and protrudes slightly forward.

In women, such a structure of the sphincter may be due to the fact that its muscles are stretched too much.

How does defecation occur?

The rectum is part of the large intestine, which also includes the sigmoid, ascending, descending and transverse. You need to understand how everything works in general in order to look at the rectum individually.

In men and women, approximately 4 liters of digested food (chyme), which comes from the stomach, enters the large intestine per day from the small intestine.

The large intestine mixes this pulp, resulting in the formation of feces in a person.

This happens due to the fact that the organ performs wave-like contractions, which causes the chyme to thicken. Ultimately, out of 4 liters of digested food, about 200 g of feces remain.

Typically, feces consist not only of chyme residues, but also of mucus, cholesterol, bacteria, cholic acid, etc.

The organ absorbs food, and all toxic and harmful substances chyme penetrates the blood, which enters the liver. In the liver, “harmful” blood is retained and then released along with bile.

After all this, bowel movement occurs, which is ensured by the actions of certain intestinal mechanisms.

With the help of peristalsis, feces enter the sigmoid colon, where they accumulate and are temporarily retained.

Stopping further movement of feces in this part of the intestine occurs due to contractions of the muscles that are located in the intestine.

Not only the intestinal muscle layer, but also the abdominal muscles help push out the contents of the intestines.

Additional help from another muscle group helps push feces into the anal canal for constipation and various cramps. After defecation, the organ is free for some time and does not fill.

This part of the intestine has a strong influence on the functioning of the stomach. If any problems arise, this affects the digestive process, the secretion of saliva and bile.

The brain also affects defecation: if a person is worried or tired, it delays bowel movements.

Possible diseases

Since the structure of the intestine in the female and male body is different, there are also quite a lot of diseases that can be found in this organ.

One of the most common diseases of the rectum is proctitis. Simply put, inflammation of the mucous membrane.

This disease can be caused by excessive consumption of spicy foods and spices, as well as constipation, during which stool stagnation occurs.

Feces can remain in the “pockets” between the columns of Morgagni, gradually poisoning the body, which can also lead to congestive proctitis.

Inflammation of the rectal mucosa can begin after unsuccessful laser therapy.

For example, if a person has a tumor in the pelvic area, then as a result radiation therapy Proctitis may well develop.

Inflammation of the mucous membrane can also occur from hypothermia, hemorrhoids, cystitis, prostatitis, etc.

Proctitis can be chronic or acute. The first type of pathology occurs almost unnoticed, accompanied by slight itching and burning in the anal canal.

Acute proctitis occurs suddenly and is characterized by high temperature, heaviness in the intestines, chills, burning in the intestines.

This type of proctitis occurs infrequently, with timely treatment maybe enough quick recovery sick.

But the prognosis for chronic proctitis is more disappointing, because with this type of disease exacerbations periodically occur.

Rectal prolapse is a pathology in which the wall of the organ falls out through the sphincter.

This is most often observed in women who have undergone a difficult birth, since after it the woman’s anus muscles can be significantly stretched and injured, and ruptures are possible.

However, bowel prolapse also occurs in men. Typically, this can occur due to changes in the muscles of the anus during the aging process, from bowel surgery. Constipation can lead to pathology if a person regularly strains for a long time in the toilet.

Usually the disease begins with constipation and other difficulties during bowel movements in childhood, but the first signs of the disease in adulthood are also possible.

With this pathology, a person begins to experience itching in the anus, fecal incontinence, and blood and mucus are released.

Diagnosis of rectal prolapse is made by palpation. The doctor may also ask the patient to push - then part of the intestine becomes visible. If polyps are suspected, a colonoscopy may be performed.

For adults in such cases, only surgical intervention is indicated. During the operation, the patient's intestinal ligaments are strengthened.

If a person also complains of incontinence, then the muscles of the anus are additionally strengthened.

Although the operation is rather large, it can be performed by almost anyone – even people old age.

Quite often, intestinal prolapse occurs along with uterine prolapse in women. If a woman is elderly or does not intend to have children, then the uterus is removed.

If bowel prolapse occurs in young man without other health problems, they may prescribe conservative treatment, which includes special physical exercises that strengthen the muscles of the anus, and a diet rich in essential vitamins.

And also to get information about its structure and its functioning, then read this article.

It will give you a general idea of ​​the purpose of the final part. digestive tract person.

General information

It is the final section of the digestive tract, responsible for the processes of final evacuation of feces from the human body.

The size of the rectum in men and women does not differ much from each other and can range from thirteen to twenty-three centimeters.

Its length, rather, depends not on the gender of an adult, but on his build and constitution.

In large (not to be confused with “full”) people, the length of this intestine will be greater, and in slender men and women it will be shorter.

The length of the intestine in children is smaller sizes, but gradually increases as they grow older.

The diameter of the area in question may also vary depending on the structure of the person and various pathological factors.

The normal diameter of the human rectum ranges from two and a half to seven and a half centimeters.

Its walls are elastic, so it can stretch and contract within the stated limits.

It is a mistake to think that the rectum has straight structure. In fact, this area of ​​the digestive tract has two bends.

The first bend is called “sacral” due to the fact that its direction “points” towards the sacral bones of the coccyx.

The second bend of the rectum is called “perineal” because its bend is directed towards the perineum.

The rectum of both an adult and a child from the first days of his life has three sections. Each of them has its own specific dimensions.

The lower part of this area is the narrowest and leads directly to the anus, which is why it is called the “perineal” or “anal” canal. The length of the section does not exceed four centimeters.

The middle section of the area under consideration is a canal called “ampullary”.

Its length is from ten to twelve centimeters, it has the most wide structure compared to the other two departments.

The length of the third section, called “supra-ampullary”, does not exceed six centimeters.

If during diagnostics aimed at studying the condition intestinal system person, it turns out that the area in question is larger or smaller in size, different from the norm, then this fact may indicate the presence of some pathological process occurring in his body.

Typical diseases that can modify the mucous membranes of the area under consideration and provoke its increase in size are hemorrhoids and various tumor processes both benign and malignant.

Functions of the rectum

As mentioned above, the human rectum has the most important function, which consists in the timely evacuation of feces from the human body.

The muscle tissue that covers the walls of this intestine makes certain contracting movements that push feces towards the sphincter.

If there are any problems, for example, hemorrhoids, cysts or tumors, feces cannot always leave the human body in a timely manner.

Stuck in the rectum, feces begin to decompose and rot, poisoning the body with a large number of toxins that negatively affect human health.

Therefore, problems arising in the rectal area cannot be ignored. If you experience the first difficulty with the urge to defecate, you should not treat it at home, but immediately consult a doctor.

Proctologists (in some cases, gastroenterologists) are involved in solving problems localized in the area under consideration.

These doctors are accepted in any municipal or private clinics.

Making an appointment with them is the best thing you can do to solve the problem as quickly as possible or at least significantly mitigate it acute symptoms, which makes its own adjustments to your usual lifestyle.

Despite the fact that the rectum ends in a through hole, designed by nature to remove food waste from the body, this intestine is not a through canal.

The muscle tissue that is located under the mucous membrane of this intestine allows a person to retain processed food lumps within the body for some time.

This process is realized thanks to the statistical role of the rectum. The second role of this intestine is called “dynamic” - it allows the evacuation of feces.

The body of a healthy person easily performs the functions of containing and evacuating feces.

If there are any malfunctions in the functioning of the intestinal system, for example, incontinence of processed food lumps or, conversely, a false urge to defecate when the tank is empty, then we can talk about complete or partial dysfunction of this zone.

Improper functioning of the intestinal system and anal sphincter is a reason to immediately consult a doctor.

The cause of such dysfunctions may be various diseases in men and women who need to be blocked or treated at the very beginning of their appearance.

It is important to understand that disruptions in the functioning of the rectum can lead to changes in the functioning of other body systems.

If specific diseases in this area are not treated, then serious inflammation of the entire intestinal system can be provoked, which will develop into sepsis.

Diseases that cause rectal dysfunction

As mentioned above, there are a number of specific diseases that can produce dysfunction in the rectal area and disrupt its normal functioning.

Most of these diseases have chronic course and does not always respond successfully to medical or surgical treatment.

If you have any disease that impairs the functioning of the area in question, then do not give up on your well-being, but contact your doctors and get them to prescribe adequate treatment for the problem.

Even if it cannot completely solve the main problem causing rectal dysfunction, it will significantly soften the symptoms and allow you to return to your usual pace of life.

The most common disease that occurs in the rectal area is hemorrhoids.

This pathology is characterized inflammatory processes, localized in hemorrhoidal veins, creating nodes in the rectum and anus.

IN advanced cases the intestine, compressed by these veins, may partially exit the anus.

Another pathology that is characteristic of this area, but is diagnosed much less frequently than hemorrhoids, is the appearance of neoplasms of various etiologies.

These growths may be polyps, which can be removed during endoscopic surgery, or rectal cancer.

The last pathology - rectal cancer - requires mandatory and long-term treatment, during which a person is prescribed courses of chemotherapy and surgery aimed at removing the cancerous tumor.

Rectal cancer, which is in the first stage of its development, is considered a curable disease.

Cancer for more late stages existence can be cured in far from one hundred percent of cases.

How do you know when it's time to see a doctor? There are a number of specific and nonspecific symptoms, which may indicate various pathological processes occurring in the rectal area. The presence of at least two or three of them is a reason for an immediate visit to the clinic.

Symptoms inherent in rectal pathologies:

• severe discomfort in the declared area, which has a recurrent course;
• pain that accompanies the act of defecation or occurs on its own, without reference to any specific processes;
• burning and itching in the sphincter area;
• anal bleeding;
• stool containing mucus or containing blood;
• prolonged constipation;
• signs of general intoxication of the body, provoked by prolonged stagnation of decomposing and rotting food lumps within the body;
• psycho-emotional instability caused by constant discomfort and persistent pain that bothers the person suffering from the problem.

After reading this article, you were able to learn about the structure of the human rectum, as well as what functions it performs in the body.

If you feel any of the symptoms mentioned in this paragraph of the article, then do not try to self-medicate and under no circumstances use various folk remedies without consulting a doctor.

Most of the decoctions and poultices that supposedly help with the pathologies of the stated area demonstrate their inconsistency.

Treatment of problems arising in this area must be professional and adequate.

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The rectum (rectum) is the final, sixth section of the large intestine, located entirely in the pelvic cavity, lying on its posterior wall formed by the sacrum, coccyx and posterior section pelvic floor and in the perineal area (regio analis). The rectum begins from the end of the pelvic section of the sigmoid colon, most often at the level of the third sacral vertebra. The rectum is located in all three floors of the pelvis: The peritoneal floor contains the suprampulse section and a small section of the rectal ampulla; in the subperitoneal - most of the ampulla. The two sections of the rectum lying in the pelvic cavity (above the pelvic diaphragm) belong to the pelvic part of the rectum, the distal section of the rectum belongs to the perineal part, corresponding to the anal canal - the third section ending in the perineal area with the anus.

Fig. 4 Peritoneum and fascia of the pelvic floor from the front. Topography of the rectum. 1 - ureter; 2 - common iliac vein on the right; 3 - general iliac artery left; 4 - femoral nerve; 5 - external iliac vein on the left; 6 - rectum; 7 - ischiorectal fossa; 8 - external anal sphincter; 9 - muscle that lifts the ani; 10 - upper fascia of the pelvic diaphragm; 11 - lower fascia of the pelvic diaphragm; 12 - internal obturator muscle; 13 - peritoneum; 14 - psoas major muscle; 15 - iliacus muscle

The length of the rectum is subject to individual fluctuations depending on the age and height of the person. The distance from the upper edge of the 3rd sacral vertebra to the anus is 15-20 cm. The length of the rectum is divided into 3 sections: supramullary (including colon pelvinum) rectosigmoid - 5-6 cm; ampullary section 10-12 cm; perineal (pars analis) or sphincter zone from 2 to 4 cm. (A.M. Aminev)

Along its length, the rectum makes two bends in the frontal and two bends in the sagittal plane. The suprampullary section and ampulla are adjacent to the sacrum and in the sagittal plane form an upper sacral curve (100-110 degrees), open anteriorly; between the pelvic and perineal parts at the level of the coccyx, a lower, coccygeal, perineal bend is formed, open posteriorly and downward.

In the frontal plane, the rectum has: a lower bend with a convexity to the left, formed by the supramullary section and the ampulla; and an upper bend directed to the right. The radii of the rectum bends must be taken into account when passing the sigmoidoscope tube.

With the beginning of the development of proctology, the rectum in the domestic literature is divided into five sections: supramullary (rectosigmoid), upper ampullary, mid-ampullary, lower ampullary, perineal sections (S. Holdin).

It is generally accepted to distinguish two sections along the rectum, separated by the pelvic diaphragm: the pelvic and perineal sections (canalis analis). The pelvic section of the rectum is divided into the supramullary part and the ampulla of the rectum.

The wall of the rectum consists of four membranes: serous, muscular, supramucosa and mucosa. The mucous membrane covers the proximal half of the rectum along the anterior and lateral walls. The distal half of the intestine does not have peritoneum, and the muscular wall is surrounded by visceral fascia.

The muscular layer consists of two layers - the outer longitudinal and the inner circular, thicker. The longitudinal layer is a continuation of the muscle bands of the sigmoid colon, which expand on the rectum and cover the intestine on all sides. Some of the muscle fibers of the stratum oblongata are woven into the levator ani muscle, and some reach the skin of the anus. The circular muscle layer in the distal part of the intestine and in the area of ​​the anal canal gradually thickens, forming the internal anal sphincter, which, without the participation of the external one, does not have the ability to retain feces and gases.

The external anal sphincter, formed by the striated muscles, has a predominant role in the obturator function. Topographically and anatomically, it belongs to the perineal area, but is functionally connected with the internal sphincter. The external sphincter consists of three muscle bundles: subcutaneous, superficial and deep. Any of these bundles is capable of independently ensuring the retention of dense feces, but is ineffective for retaining loose stools and gases; this requires the participation of all three bundles.

Despite the lack of a clear anatomical boundary between the bundles of the external sphincter, a description of each individually is given. The fibers of the subcutaneous bundle cover the anus in a semi-oval shape and are attached to the skin in front of the anus. The superficial fascicle covers the posterior semi-oval and is attached to the anal-coccygeal ligament, which connects to the coccyx. As a result, for anus, a small triangular space remains between the right and left parts of the beam. In front, part of the superficial fibers is woven into the transverse muscles of the perineum at tendon center, and between them a space can also form into which the anterior, median fistulas of the rectum open. The deep fascicle is adjacent to the puborectalis muscle.

The third or deep part of the external sphincter consists of circular fibers that form a wide ring around the anal canal - this is its most powerful part. The sphincter covers the anus not with a vertical tube, but as if with a cone, which narrows downwards towards the anus. The subcutaneous part of the external sphincter is closer to the wall of the anal canal than the superficial part, and even more so the deep part, which is 2 cm from the intestinal wall. The height of the external sphincter is 26 mm and the thickness is 10 mm. This allows you to safely cut the wall of the rectum to a depth of 1 cm. The muscle fibers of the levator ani muscle pass between the three parts of the external sphincter and are attached to the skin.

In addition to the external sphincter of the muscles directly related to the rectum, the levator ani muscle - or the pelvic diaphragm - is important. The levator ani muscle is divided into three parts - the iliococcygeus muscle, which originates from the ilium, from the fascia of the obturator muscle and from the posterior part of the tendinous arch and is attached to the sacrum and coccyx; the pubococcygeus muscle originates from the tendinous arch and the pubic bone and is attached to the coccyx and the ileal-anal ligament, the fibers of this muscle are woven into the wall of the rectum and end in the skin of the anus; The puborectalis muscle begins at the anterior part of the pubic bone next to the pubococcygeus. Both halves of this muscle form a loop that goes around the back of the rectum. During digital examination, this “loop” is felt in the form of a cord separating the perineal section of the rectum from its ampulla.

At a distance of 10 cm from the anus, the annular muscle forms another thickening - m. sphincter ani tertias (involuntary) - Hepner (Hopfner) muscle.

Features of the structure of the rectal wall

The mucous membrane of the rectum and anal canal is covered with epithelium and contains intestinal glands - crypts. Single lymphatic follicles are located in the submucosal layer.

The mucous membrane of the ampulla has three (sometimes more) transverse folds protruding into the lumen of the rectum (plicae transversales recti). The middle one is located on the right wall of the intestine, approximately 6 cm from the anus, and is the largest - the Kohlrausch fold.

The other two folds are on the left wall of the rectum. In addition to transverse folds, there are a large number of non-permanent folds running in different directions.

The mucous membrane of the lower part of the rectum forms folds located longitudinally in the submucosal layer - anal columns (columna anales), wide and the height of which increases downwards. The upper ends of the anal columns correspond to the rectal-anal line (linea anorectalis). The bases of the anal columns are connected transverse folds. These folds, designated as semilunar valves (valvulae semilunars), form the anal sinuses (crypts) (sinus anales). The sinuses are often injured due to constipation or diarrhea, leading to acute paraproctitis, rectal fistulas or anal fissures. The number of sinuses, like the number of columns, ranges from 6 to 12.

Approximately at the level of the middle of the anal canal, the line of attachment of the levator ani muscle is located along the circumference; upon palpation of this section, a circular groove is identified, designated by Hilton's white line. The groove corresponds to the border between the external and internal sphincters. The rectum communicates with the opening of the anus through the anal canal, the length of which is 2.2-3 cm.

The anal canal is lined, replacing each other, by three types of epithelium, therefore three histological zones are distinguished in the canal. Above the anal-cutaneous line, an intermediate zone begins, covered with stratified squamous non-keratinizing epithelium. Eats here sebaceous glands, but no hair. The intermediate zone continues to the jagged line formed by the free edges of the anal valves. Above the dentate line, single-layer columnar epithelium begins. The dentate line is formed by the edges of the anal valves - pockets formed by the intestinal mucosa between the morganian columns (the columns go from the dentate line, there are from 5 to 10 of them).

The columns extend from the dentate line to the upper surgical border of the anal canal, which passes at the level of the puborectalis muscle. The jagged line is the most important landmark. The boundary between the endodermal (upper) and ectodermal (lower) parts of the rectum passes along or near it. Blood supply, lymphatic drainage, innervation and the nature of the lining all differ in these parts, developing from different embryonic rudiments.

In the male pelvis, the most important cellular spaces include the prevesical space of Retzius, located between the intra-abdominal fascia, attached to top edge pubic symphysis, and prevesical fascia covering the bladder.

V. D. Ivanova, A. V. Kolsanov, S.S. Chaplygin, P.P. Yunusov, A.A. Dubinin, I.A. Bardovsky, S. N. Larionova

In case of failures, it is important to visit a doctor in a timely manner to prevent complications and negative consequences.

Structure

The lower part of the intestine is located in the pelvic area. The rectum is important for the entire human body. It promotes the removal of processed products gastrointestinal tract and fluid absorption. Based on the condition of the lower intestine, the performance of the digestive tract can be assessed.

The coordinated work of the organ allows the body to receive all the necessary substances and elements. The state of many systems of the human body depends on its activity.

The structure of the rectum includes mucous, submucosal and muscular layers. At the end is the opening of the anus. The outer covering of the terminal section is quite durable. There is a thin layer of fat inside.

In women, the same one runs around the cervix. U strong half humanity is surrounded by such a layer prostate and seminal vesicles.

In the area above the anus, there are vertical folds. In medical language they are called columns of Morgagni. There is a small space between them where elements of feces or foreign bodies. They contribute to the onset of the inflammatory process.

Functions

In the human body, the final section of the digestive tract performs several tasks. It cleanses the gastrointestinal tract of toxins and other unnecessary elements.

As waste accumulates, it rots and acquires an unpleasant odor. They poison the human body. They are eliminated through the rectum.

Main functions of the organ:

1. Statistical. It consists in the accumulation and retention of feces and excess gases.
2. Dynamic. This is the ability of the terminal section to help perform the act of defecation. A person feels the urge to evacuate when accumulating large quantity feces and gases. The interoceptive apparatus of the lower digestive tract is irritated. The intestinal walls contract, the anus rises, and the sphincter relaxes. This is how the act of defecation begins.

Like any organs, the rectum is not protected from damage by various pathological processes.

Diseases

Any illnesses disrupt the quality and level human life. A qualified doctor can diagnose the disease. He will prescribe not only tests, but also additional medical examinations.

Diagnostics is carried out:

• physiological methods;
• X-ray methods;
• laboratory means.

The most effective and informative examination is a colonoscopy. This exact way identifying pathological processes in the area of ​​the final part of the digestive tract. With its help, doctors can even detect cancer cells.

Frequent illnesses:

1. Inflammation leading to proctitis.
2. Bowel prolapse. The main reason is weakness of the muscles that form the pelvic floor.
3. Polyps. Patients do not feel much discomfort, but there is a possibility of polyps degenerating into malignant neoplasms.
4. Cancer. Dangerous disease, which most often requires surgical intervention. During the manipulation, doctors partially or completely remove the intestine.
5. Formation of cracks. The appearance of tears in the mucous membrane.

Timely diagnosis of the disease increases the patient's chances of a full recovery. Preventing a disease is always easier than eliminating it later. In most cases, conservative treatment is successful.

Sometimes surgery is required. Doctors remove the organ partially or completely and install artificial elements.

If there are no contraindications, specialists can perform surgery for the purpose of reconstruction, that is, the creation of an intestine from a certain section of the intestine.

We must not forget about prevention. You need to visit a specialist every year and undergo a comprehensive medical examination.