The structure of the ureters, bladder, urethra: female and male. Urinary systems

The urinary tract includes the renal calyces and pelvis, ureters, bladder and urethra, which in men simultaneously performs the function of removing seminal fluid from the body and will therefore be described in the chapter on the reproductive system. The structure of the walls of the renal calyces and pelvis, ureters and bladder in general outline similar. They distinguish between the mucous membrane, consisting of the transitional epithelium and the lamina propria, the submucosa, the muscular and outer membranes. In the wall of the renal calyces and renal pelvis, after the transitional epithelium, there is a lamina propria of the mucous membrane, which imperceptibly passes into the connective tissue of the submucosa. The muscularis propria consists of two thin layers of smooth muscle cells: the inner (longitudinal) and the outer (circular). The ureters have a pronounced ability to stretch due to the presence of deep longitudinal folds of the mucous membrane in them. The mucous membrane of the bladder consists of transitional epithelium and lamina propria. In it, small blood vessels come especially close to the epithelium. In a collapsed or moderately stretched state, the mucous membrane of the bladder has many folds. They are missing in anterior section the bottom of the bladder, where the ureters flow into it and the urethra exits.

Urinary systems A. Kidneys. Nephrons.

Urinary organs. Development. During embryonic period three paired excretory organs are laid down in succession: the anterior kidney, or prebud, the primary kidney, and the permanent, or final, kidney. The forebud is formed from the anterior 8-10 segmental legs of the middle germ layer. In the human embryo, the kidney does not function as a urinary organ and soon after its formation undergoes reverse development. The primary kidney is the main excretory organ during a significant period of embryonic development. It is formed from large number segmental legs located in the body area of the embryo. Renal tubules differentiate from nephrogenic tissue. At one end, capsules are formed that enclose the vascular glomeruli. BUD. Structure. The kidney is covered with a connective tissue capsule and, in addition, in front serosa. The substance of the kidney is divided into cortex and medulla. The cortex is dark red in color and is located in a common layer under the capsule. The medulla is lighter in color and is divided into 8-12 pyramids. The kidney parenchyma is represented by epithelial renal tubules, which, with the participation of blood capillaries, form nephrons. There are about 1 million of them in each kidney. The nephron is the structural and functional unit of the kidney. The length of its tubules is up to 50 mm, and all nephrons are on average about 100 km. The nephron includes: a glomerular capsule, a proximal convoluted tubule, a proximal straight tubule, a thin tubule in which a descending part and an ascending part are distinguished, a distal straight tubule and a distal convoluted tubule.

Male reproductive system.

Testicles, or testes, are male gonads in which the formation of male germ cells and the male sex hormone occurs. Development. During the development of the testis, the future connective tissue capsule of the testis is formed along the upper edge of the primary bud - the tunica albuginea, which separates the genital cords from the genital ridge that gave them origin. Subsequently, the reproductive cords develop into seminiferous tubules, but part of these cords turns into the testicular network. Initially, the seminiferous tubules and the tubules of the testicular network are separated and come into contact later. Structure. Outside, most of the testis is covered with a serous membrane - the peritoneum, behind which there is a dense connective tissue membrane, called the albuginea. At the posterior edge of the testis, the tunica albuginea thickens, forming a mediastinum, from which layers of connective tissue extend deep into the gland, dividing the gland into lobules (about 250 lobules), each of which contains 1-4 convoluted seminiferous tubules. The wall of the seminiferous tubule is formed by its own membrane, consisting of a basal layer, a myoid layer and a fibrous layer, lined from the inside by the so-called spermatogenic epithelium located on the basement membrane. The basal membrane of the spermatogenic epithelium in humans is about 80 nm thick and forms projections directed both inside the seminiferous tubules and into the outer layers. The basal layer (the inner non-cellular layer located between two basement membranes (spermatogenic epithelium and myoid cells), consists of a network of collagen fibers. The myoid layer (inner cellular layer) is formed by special myoid cells containing actin filaments, but different in structure from typical smooth muscle cells. Myoid cells provide rhythmic contractions of the tubule wall. The fibrous layer is directly adjacent to the inner noncellular layer, formed by the basement membrane of myoid cells and collagen fibers. The seminiferous tubules contain hemocapillaries and lymphocapillaries that ensure the exchange of substances between the blood and the spermatogenic epithelium. The epithelium has two main populations of cells - supporting cells, or sustentocytes, and spermatogenic cells, which are at various stages of differentiation. The supporting cells lie on the basement membrane, have a pyramidal shape and reach their apex into the lumen of the convoluted seminiferous tubule. Generative function. Spermatogenesis. The formation of male germ cells (spermatogenesis) occurs in convoluted seminiferous tubules and includes 4 successive stages or phases: decomposition, growth, maturation and formation. The initial phase of spermatogenesis is the reproduction of spermatogonia, which occupy the most peripheral (basal) position in the spermatogenic epithelium. IN next period spermatogonia stop dividing and differentiate into first-order spermatocytes (growth period). The syncytial groups of spermatogonia move to the adluminal zone of the spermatogenic epithelium. During the period of growth, spermatogonia increase in volume and enter the first meiotic division. The prophase of the first division is long and consists of 5 stages: leptotene, zygotene, pachytene, diplotene, diakinesis. In the loose connective tissue between the loops of convoluted tubules there are interstitial cells - glandulocytes, which accumulate here around the blood capillaries. These cells are relatively large, round or polygonal in shape, with acidophilic cytoplasm, vacuolated along the periphery, containing glycoprotein inclusions, as well as lumps of glycogen and protein crystalloids in the form of rods or ribbons.

Ureter- a paired tubular organ, about 30 cm long, with a diameter from 3 to 9 mm. The main function of the ureter is to drain urine from the renal pelvis into the bladder. Urine moves through the ureters due to rhythmic peristaltic contractions of its thick muscular lining. From the renal pelvis, the ureter goes down the posterior abdominal wall, approaches the bottom of the bladder at an acute angle, and obliquely pierces it back wall and opens into its cavity.

Topographically, the ureter is divided into abdominal, pelvic and intramural parts. The latter is a small section 1.5-2 cm long inside the wall of the bladder. In addition, three bends are distinguished in the ureter: in the lumbar, pelvic areas and before flowing into the bladder, as well as three narrowings: at the junction of the pelvis into the ureter, at the transition of the abdominal part into the pelvic part and before flowing into the bladder.

The wall of the ureter consists of three membranes: the inner mucosa, the middle smooth muscle and the outer adventitia. The mucous membrane is lined with transitional epithelium and has deep longitudinal folds, so the lumen of the ureter in a cross section has a star-shaped shape. The middle muscular layer at the top of the ureter consists of two muscle layers: internal longitudinal and external circular, and in the lower part - from three layers: internal and external longitudinal and middle circular layers. The adventitia of the ureter is formed by loose fibrous connective tissue. The peritoneum covers the ureters, like the kidneys, only in front, these organs lie retroperitoneal

With fluoroscopy of the ureters at In a living person, in addition to anatomical narrowings, one can see physiological narrowings associated with ureteral peristalsis.

Bladder- an unpaired hollow organ for storing urine, which is periodically discharged from it by the urethra. Bladder capacity - 500-700 ml. Its shape changes depending on the filling with urine: from flattened to ovoid or pear-shaped. The bladder is located in the pelvic cavity behind the pubic symphysis, from which it is separated by a layer of loose tissue. When the bladder fills with urine, the top of the bladder steps and comes into contact with the front abdominal wall. The posterior surface of the bladder in men is adjacent to the rectum, seminal vesicles and ampoules of the seminal ducts, in women - to the cervix and vagina (their anterior walls). In the bladder there are:

1) the apex of the bladder - the anterior-superior pointed part facing the anterior abdominal wall;

2) the body of the bubble - the middle most part of it;

3) the bottom of the bladder - facing downwards and backwards;

4) bladder neck - the narrowed part of the bottom of the bladder.

At the bottom of the bladder there is a triangular-shaped area - the vesical triangle, at the tops of which there are 3 openings: two ureteral and the third - the internal opening of the urethra.

The wall of the bladder consists of three membranes: the inner - mucous membrane with a well-developed submucous base, the middle - smooth muscle and the outer - adventitial and serous (partially). The mucous membrane, together with the submucosa, forms well-defined folds, with the exception of the bladder triangle, which does not have folds due to the absence of a submucosa there. The surface of the mucous membrane is lined with stratified transitional epithelium. The muscular layer of the bladder consists of three layers of smooth muscle tissue: two longitudinal - external and internal and middle, the most developed - circular. In the area of the neck of the bladder at the beginning of the urethra, a circular (circular) layer of muscle forms a compressor - the sphincter of the bladder, which contracts involuntarily. The muscular membrane, contracting, reduces the volume of the bladder and expels urine out through the urethra. Due to this function of the muscular lining of the bladder, it is called the urinary ejector muscle. . The peritoneum covers the bladder from above, from the sides and from behind. The filled bladder is located mesoperitoneally in relation to the peritoneum; empty, collapsed - retroperitoneal.

Urethra men and women have large morphological gender differences, so we will consider each of them separately.

Male urethra is a soft elastic tube 18-23 cm long, 5-7 mm in diameter, which serves to remove urine from the bladder to the outside and seminal fluid. Begins internal hole and ends with an external opening located on the head of the penis. Topographically male urethra divided into 3 parts: prostatic about 3 cm long, located inside the prostate gland, membranous part up to 1.5 cm lying in the pelvic floor from the apex of the prostate gland to the bulb of the penis, and spongy part 15-20 cm long, passing inside corpus spongiosum penis. In the membranous part of the canal there is a voluntary sphincter of the urethra made of striated muscle fibers.

The mucous membrane of the prostatic part of the urethra is lined with transitional epithelium, the membranous and spongy parts - with multi-row prismatic epithelium, and in the area of the head of the penis - with multilayered squamous epithelium with signs of keratinization. The mucous membrane contains a large number of small mucous glands. Behind the mucosa is a layer of smooth muscle cells and an adventitial layer. In urological practice, the male urethra is divided into anterior, corresponding to the spongy part of the canal, and posterior, corresponding to the membranous and prostatic parts.

Female urethra It is a short, slightly curved, convex tube facing backward, 2.5-3.5 cm long, 8-12 mm in diameter. Located in front of the vagina and fused With its front wall. It starts from the bladder with the internal opening of the urethra and ends with the external opening, which opens anteriorly and above the opening of the vagina. At the point where it passes through the urogenital diaphragm there is an external urethral sphincter, consisting of striated muscle tissue and contracting voluntarily. The wall of the female urethra is easily extensible. It consists of mucous and muscular membranes. The mucous membrane of the canal near the bladder is covered with transitional epithelium, which then becomes multilayered squamous non-keratinizing with areas of multirow prismatic. The mucous membrane with the submucosa forms longitudinal folds and contains numerous glands; it has blind depressions - lacunae of the urethra. The muscular layer consists of bundles of smooth muscle cells that form 2 layers: the inner longitudinal and outer circular.

47. Stages of urine formation. The process of formation of primary urine. Formation of final urine. Amount and composition of primary and final urine. Daily diuresis.

The kidneys play an exceptional role in maintaining the normal functioning of the body. Main function kidney - excretory. They remove decay products, excess water, salts, harmful substances and some medications from the body. The kidneys maintain the osmotic pressure of the body's internal environment at a relatively constant level by removing excess water and salts (mainly sodium chloride). Thus, the kidneys take part in water-salt metabolism and osmoregulation.

The kidneys, along with other mechanisms, ensure the constancy of the blood reaction (blood pH) by changing the intensity of the secretion of acidic or alkaline salts phosphoric acid when the blood reaction shifts to the acidic or alkaline side.

The kidneys are involved in the formation (synthesis) of certain substances, which they subsequently remove. The kidneys perform a secretory function. They have the ability to secrete organic acids and bases, potassium and sodium ions. The participation of the kidneys not only in mineral, but also in lipid, protein and carbohydrate metabolism has been established.

Thus, the kidneys, regulating the amount osmotic pressure in the body, the constancy of the blood reaction, carrying out synthetic, secretory and excretory functions, takes an active part in maintaining the constancy of the composition of the internal environment of the body (homeostasis).

MECHANISMS OF URINE FORMATION. Urine is formed from blood plasma flowing through the kidneys and is complex product nephron activity. Currently, urine formation is considered as a complex process consisting of two stages: 1) the formation of primary urine by filtration (ultrafiltration) and 2) the formation of secondary urine by reabsorption (reabsorption), secretion and synthesis.

Glomerular ultrafiltration. In the capillaries of the glomeruli of the renal corpuscle, water is filtered from the blood plasma with all the inorganic and organic substances of low molecular weight dissolved in it. This fluid enters the capsule of the renal glomerulus, and from there into the renal tubules. Its chemical composition is similar to blood plasma, but contains almost no proteins. The resulting glomerular filtrate is called primary urine. The process of filtration of primary urine is facilitated by high hydrostatic pressure in the capillaries of the glomeruli, equal to 70-90 mm Hg. It is counteracted by the oncotic pressure of the blood, equal to 25-30 mm Hg, and the pressure of the fluid in the cavity of the nephron capsule (renal corpuscle), equal to 10-15 mm Hg. Therefore, the critical value of the blood pressure difference that ensures glomerular filtration is, on average, 75 mm Hg. - (30 mm Hg + 15 mm Hg) = 30 mm Hg.

Urine filtration stops if the blood pressure in the glomerular capillaries drops below 30 mm Hg.

Tubular reabsorption. In the renal tubules, reabsorption (reabsorption) of water, glucose, some salts and a small amount of urea from primary urine into the blood occurs. Final, or secondary urine is formed, which in its composition differs sharply from the primary. It does not contain glucose, amino acids of some salts and the concentration of urea is sharply increased. During the day, 150-180 liters of primary urine are formed in the kidneys. Due to the reabsorption of water and many dissolved substances in the tubules, the kidneys excrete only 1–2 liters per day. final urine. Reabsorption can occur actively or passively. Active reabsorption carried out due to the activity of the epithelium of the renal tubules with the participation of special enzyme systems with energy consumption. Glucose, amino acids, phosphates, and sodium salts are actively reabsorbed. These substances are completely absorbed in the tubules and are absent in the final urine. Due to active reabsorption, it is also possible for substances to be reabsorbed from urine into the blood, even when their concentration in the blood is equal to the concentration in the tubular fluid. Passive reabsorption occurs without energy consumption due to diffusion and osmosis. A major role in this process belongs to the difference in oncotic and hydrostatic pressure in the capillaries of the tubules. Due to passive reabsorption, water, chlorides, and urea are reabsorbed. From the primary urine in the proximal tubules, the so-called threshold substances: glucose, amino acids, vitamins, sodium, potassium, calcium, chlorine ions, etc. They are excreted in the urine only if their concentration in the blood is higher than the body’s constant values. For example, glucose is excreted in the urine in the form of traces when the blood sugar level is 8 - 10 mmol/l. Thus, a value of 8 -10 mmol/l will characterize the threshold for glucose excretion by the kidneys. Non-threshold substances are excreted in the urine at any concentration in the blood. Getting from the blood into the primary urine, they are not reabsorbed. In this case, the content of non-threshold substances (i.e. metabolic products) in the final urine reaches large quantities. For example, there is 65 times more urea in the final urine than in the blood, 75 times more creatinine, and 90 times more sulfates.

The descending and ascending limbs of F. Henle's loop form the so-called rotary-countercurrent system. Closely touching each other, the descending and ascending knees function as a single mechanism. The essence is like this collaboration lies in the fact that water flows abundantly from the cavity of the descending limb into the tissue fluid of the kidney. This leads to thickening in this knee, i.e. to increase the concentration of various substances in urine. From the ascending limb, sodium ions are actively removed into the tissue fluid, but water is not removed. An increase in the concentration of sodium ions in the tissue fluid contributes to an increase in its osmotic pressure, and consequently, to increased suction of water from the descending limb. This causes even greater thickening of urine in the loop of F. Heckle. Here, as elsewhere in living systems, the phenomenon of self-regulation again manifests itself. The release of water from the descending leg promotes the release of sodium ions from the ascending leg, and sodium in turn causes the release of water. Thus, the loop of Henle works as a urine concentrating mechanism. Passing through the loop of Henle of the nephron, urine releases water, thickens, and becomes more concentrated. Thus, large amounts of water and sodium ions are reabsorbed in the nephron loop.

In the distal convoluted tubules, further absorption of sodium, potassium, water and other substances occurs. Unlike the proximal convoluted tubule and nephron loop, where the reabsorption of sodium and potassium ions does not depend on their concentration (obligatory reabsorption), the amount of reabsorption of these ions in the distal tubules is variable and depends on their level in the blood (facultative reabsorption). Consequently, the distal sections of the convoluted tubules regulate and maintain the constant concentration of sodium and potassium ions in the body.

Tubular secretion. In addition to reabsorption, the process of secretion occurs in the tubules. With the participation of special enzyme systems, active transport of certain substances from the blood into the lumen of the tubules occurs. Of the products of protein metabolism, creatinine and para-aminohippuric acid undergo active secretion. This process is most pronounced when substances foreign to it are introduced into the body. Thus, active transport systems function in the renal tubules, especially in their proximal segments. Depending on the state of the body, these systems can change the direction of active transfer of substances, i.e., they provide either their secretion (excretion) or reverse absorption.

In addition to carrying out filtration, reabsorption and secretion, renal tubular cells are capable of synthesize some substances from various organic and inorganic products. Thus, hippuric acid (from benzoic acid and glycocol) and ammonia (by deamination of some amino acids) are synthesized in the cells of the renal tubules. The synthetic activity of the tubules is also carried out with the participation of enzyme systems.

Thus, urine formation is a complex process in which, along with the phenomena of filtration and reabsorption, the processes of active secretion and synthesis play an important role. If the filtration process occurs mainly due to blood pressure, that is, ultimately due to the functioning of the cardiovascular system. The processes of reabsorption, secretion and synthesis are the result of the active activity of tubular cells and require energy expenditure. This is associated with the kidneys' greater need for oxygen. They use 6-7 times more oxygen than muscles (per unit mass).

Human urine is a transparent, straw-yellow liquid, with which water and dissolved metabolic end products (in particular, nitrogen-containing substances), mineral salts, toxic products (phenols, amines), breakdown products of hormones, biologically active substances are excreted from the body. , vitamins, enzymes, medicinal compounds, etc. In total, about 150 different substances are excreted in urine. During the day, a person excretes on average from 1 to 1.5 liters of urine, predominantly of a slightly acidic reaction; Its pH ranges from 5 to 7. The reaction of urine is variable and depends on nutrition. With meat and protein-rich foods, the urine reaction is acidic, with plant foods – neutral or even alkaline. The specific gravity of urine depends on the amount of fluid taken. Normally, during the day, the specific gravity of urine is in the range of 1.010-1.025. An average of 60 g of dense substances are excreted in urine per day. Of these, organic substances are released within the range of 35-45 g/day, inorganic 15-25 g/day. From organic substances, the kidneys remove the most urea with urine: 25-35 g/day, from inorganic substances - table salt - 10-15 g/day. In addition to the main components mentioned above, per day the kidneys remove in urine such organic substances as creatinine - 1.5 g, uric acid, hippuric acid - 0.7 g each, inorganic substances: sulfates and phosphates - 2.5 g each, potassium oxide - 3.3 g, calcium oxide and magnesium oxide - 0.8 g each, ammonia -0.7 g, etc.

Daily diuresis is the process of formation and excretion of urine from the body during the day.

48. Regulation of urine formation and excretion.

Regulation of kidney activity is carried out by nervous and humoral pathways. Direct nervous regulation of kidney function is less pronounced than humoral regulation. As a rule, both types of regulation are carried out in parallel by the hypothalamus or cortex. However, turning off the higher cortical and subcortical regulatory centers does not lead to the cessation of urine formation. Nervous regulation of urine formation most affects filtration processes, and humoral regulation most affects reabsorption processes.

The nervous system can influence the functioning of the kidneys through both conditioned reflex and unconditioned reflex pathways. The following receptors are of great importance for the reflex regulation of kidney activity:

1) osmoreceptors - are excited during dehydration (dehydration) of the body;

2) volume receptors - excited when volume changes different departments of cardio-vascular system;

3) pain - with skin irritation;

4) chemoreceptors - are excited when chemicals enter the blood.

The unconditioned reflex subcortical mechanism for controlling urination (diuresis) is carried out by the centers of the sympathetic and vagus nerves, the conditioned reflex mechanism - by the cortex. The highest subcortical center for the regulation of urine formation is the hypothalamus. When the sympathetic nerves are irritated, urine filtration, as a rule, decreases due to narrowing of the renal vessels that bring blood to the glomeruli. With painful stimulation, a reflex decrease in urine formation is observed, up to complete cessation (painful anuria). Constriction of the renal vessels in this case occurs not only as a result of excitation of the sympathetic nerves, but also due to an increase in the secretion of the hormones vasopressin and adrenaline, which have a vasoconstrictor effect. When the vagus nerves are irritated, the excretion of chlorides in the urine increases due to a decrease in their reabsorption in the kidney tubules.

Bark big brain affects the functioning of the kidneys both directly through the autonomic nerves and humorally through the hypothalamus, the neurosecretory nuclei of which are endocrine and produce antidiuretic hormone (ADH) - vasopressin. This hormone is transported along the axons of hypothalamic neurons to the posterior lobe of the pituitary gland, where it accumulates, turns into an active form and, depending on the internal form, enters the blood in greater or lesser quantities, regulating the formation of urine.

The leading role of vasopressin in the humoral regulation of kidney activity has been proven by experiments. If denervated healthy kidney animal and transplant it into the neck area with blood supply from the carotid artery and blood outflow into jugular vein, then the transplanted kidney will produce urine for a long time, like a regular kidney. During painful stimulation, an isolated kidney reduces urine formation until it completely stops, just like a normally innervated kidney. This is explained by the fact that during painful stimulation the hypothalamus is excited and the production of vasopressin is increased. The latter, entering the blood, enhances the reabsorption of water from the kidney tubules and thereby reduces diuresis (urination). It has been established that vasopressin stimulates the formation of the enzyme hyaluronidase, which enhances the breakdown of hyaluronic acid, i.e. sealing substance of the distal convoluted tubules of the kidneys and collecting ducts. As a result, the tubules lose their waterproofness, and water is absorbed into the blood. With an excess of vasopressin, a complete cessation of urine formation may occur. With a lack of vasopressin, a serious disease develops - diabetes insipidus, or diabetes insipidus. In these cases, water ceases to be reabsorbed in the collecting ducts, as a result of which 20-40 liters of light urine, with low density, which lacks sugar, can be released per day.

Another steroid hormone of the adrenal cortex from the mineralcorticoid group, aldosterone, acts on the cells of the ascending limb of the loop of Henle. Under the influence of this hormone, the process of reabsorption of sodium ions increases and at the same time the reabsorption of potassium ions decreases. As a result, the excretion of sodium in the urine decreases and the excretion of potassium increases, which leads to an increase in the concentration of sodium ions in the blood and tissue fluid and an increase in osmotic pressure. With a lack of aldosterone and other mineralcorticoids, the body loses such a large amount of sodium that this leads to changes in the internal environment that are incompatible with life. Therefore, mineralcorticoids are figuratively called life-preserving hormones.

Urination is a complex reflex act consisting of simultaneous contraction of the bladder wall and relaxation of its sphincter. Involuntary reflex center urination is located in the sacral part of the spinal cord. The first urge to urinate appears in adults when the volume of the bladder increases to 150 ml. An increased flow of impulses from the mechanoreceptors of the bladder arrives when its volume increases to 200-300 ml. Afferent impulses travel to the spinal cord to the micturition center. From here, impulses travel along the parasympathetic nerve to the bladder muscle and its sphincter. A reflex contraction of the muscle wall and relaxation of the sphincter occurs. At the same time, from the spinal center of urination, excitation is transmitted to the cerebral cortex, where a sensation of the urge to urinate occurs. Impulses from the cerebral cortex travel through the spinal cord to the urethral sphincter. Urination occurs. The influence of the cerebral cortex on the reflex act of urination is manifested in its delay, intensification, or even voluntary invocation. Voluntary urinary retention is absent in newborns. She appears only towards the end of the first goal. A strong conditioned reflex of urinary retention is developed in children by the end of the second year. As a result of upbringing, the child develops a conditioned reflex delay in urge and a conditioned situational reflex: urination when certain conditions for its implementation appear.

Female genital organs.

The female genital organs serve for the growth and maturation of female reproductive cells (eggs), gestation and the formation of female sex hormones. According to their position, female genital organs are divided into internal and external. The internal female genital organs include: ovaries, uterus, fallopian tubes, vagina. The external female genitalia include the female genital area and the clitoris. Branch of medicine that studies features female body and diseases associated with disruption of the female genital organs are called gynecology.

A. Ovary - paired sex gland of mixed secretion, producing female reproductive cells and hormones. It has the shape of a flattened oval body 2.5-5.5 cm long, 1.5-3 cm wide, up to 2 cm thick. The mass of the ovary is 5-8 g. There are two free surfaces in the ovary: the medial one, facing the cavity of the small pelvis, and lateral, adjacent to the wall of the pelvis, as well as the upper tubal and lower uterine ends, the free (posterior) and mesenteric (anterior) edges.

The ovary is located vertically in the pelvic cavity on both sides of the uterus and is attached to the posterior layer of the broad ligament of the uterus through a small fold of peritoneum - the mesentery. In the region of this edge, vessels and nerves enter the ovary through a groove-shaped depression, which is why it is called the hilum of the ovary. One of the fimbriae is attached to the tubal end of the ovary fallopian tube. It goes from the uterine end of the ovary to the uterus own link ovary.

The ovary is not covered by peritoneum; on the outside it is covered with a single-layer cubic (germinal) epithelium, under which lies a dense connective tissue tunica albuginea. This ovarian tissue forms its stroma. The substance of the ovary, its parenchyma, is divided into two layers: the outer, denser one, the cortex, and the inner one, the medulla. In the medulla, which lies in the center of the ovary, closer to its gate, numerous vessels and nerves are located in the loose connective tissue. The cortex, located outside, contains, in addition to connective tissue, a large number of primary ovarian follicles, which contain embryonic eggs. A newborn girl has up to 800,000 primary ovarian follicles in the cortex (in both ovaries). After birth, the reverse development and resorption of these follicles occurs, and by the onset of puberty (13-14 years), about 10,000 of them remain in each ovary. During this period, the alternate maturation of eggs begins. Primary follicles develop into mature follicles - Graafian vesicles. The cells of the walls of the maturing follicle perform an endocrine function: they produce and release into the blood the female sex hormone - estrogen, which promotes the maturation of follicles and the development of the menstrual cycle.

The cavity of a mature follicle is filled with liquid, inside of which there is an egg on the ovarian mound. Regularly, after 28 days, the next mature follicle ruptures, and with a flow of liquid, the egg enters the peritoneal cavity, then into the fallopian tube, where it matures. The rupture of a mature follicle and the release of an egg from the ovary is called ovulation. At the site of the burst follicle, a corpus luteum forms. It acts as an endocrine gland: it produces the hormone progesterone, which ensures the development of the embryo. There are menstrual (cyclic) corpus luteum and the corpus luteum of pregnancy. The first is formed if fertilization of the egg does not occur. It operates for about two weeks. The second is formed upon the onset of fertilization and functions long time(during the entire pregnancy). After atrophy corpus luteum in its place remains a connective tissue scar - a whitish body.

Another process in a woman’s body is closely related to ovulation - menstruation. Menstruation is the periodic discharge from the uterus of blood, layers and cellular detritus (decomposition products of dead tissue), which are observed in sexually mature women. non-pregnant woman in about 4 weeks. Menstruation begins at the age of 13-14 and lasts 3-5 days. Ovulation precedes menstruation by 14 days, i.e. it occurs midway between two menstruation periods. By the age of 45-50, a woman experiences menopause (menopause), during which the processes of ovulation and menstruation stop and menopause occurs. Before the onset of menopause, women have time to mature from 400 to 500 eggs, the rest die, and their follicles undergo reverse development.

B. Uterus- an unpaired hollow muscular organ intended for the development and gestation of the fetus during pregnancy and its removal during childbirth. Located in the pelvic cavity between the bladder in front and the rectum in the back. The uterus is pear-shaped. It is divided into: a bottom facing upward and anteriorly, a body - the middle part and a neck facing downwards. The junction of the uterine body and the cervix is narrowed and is called the isthmus of the uterus. The lower part of the cervix flows into the vaginal cavity and is called the vaginal part, and top part The cervix, which lies above the vagina, is called the supravaginal part. There is a cavity in the body of the uterus, which communicates with the fallopian tubes from the bottom, and in the cervical area passes into the cervical canal. The cervical canal opens into the vagina. The size and weight of the uterus vary individually. The length of the uterus in an adult woman is on average 7-8 cm, width - 4 cm, thickness - 2-3 cm. The weight of the uterus in nulliparous women ranges from 40-50 g, in those who have given birth reaches 80-90 g. The volume of the uterine cavity is 4-6 cm 3.

The wall of the uterus is significantly thick and consists of three membranes (layers):

1) internal - mucous membrane, or endometrium;

2) middle - smooth muscle, or myometrium;

3) external - serous, or perimetry.

Around the cervix under the peritoneum there is peri-uterine tissue - the parametrium.

The mucous membrane (endometrium) forms the inner layer of the uterine wall, its thickness reaches 3 mm. It is covered with single-layer columnar epithelium and contains the uterine glands. The muscular layer (myometrium) is the most powerful, built of smooth muscle tissue, consisting of internal and external oblique and middle circular (circular) layers, which are intertwined. Contains a large number of blood vessels. Serosa (perimetry) - peritoneum covers the entire uterus, with the exception of part of the cervix. The uterus has a ligamentous apparatus by which it is suspended and secured in a curved position, as a result of which its body is inclined over the anterior surface of the bladder. Part ligamentous apparatus includes the following paired ligaments: broad, round ligaments of the uterus, rectouterine and sacrouterine ligaments.

IN. Fallopian tube or oviduct, - a paired tubular formation 10-12 cm long, through which the egg is released into the uterus (hence one of the names of the tube is the oviduct). Fertilization of the egg occurs in the fallopian tube and initial stages embryo development. The lumen of the pipe ranges from 2 to 4 mm. Located in the pelvic cavity on the side of the uterus in upper section broad ligament. One end of the fallopian tube is connected to the uterus, the other is expanded into a funnel and faces the ovary. The fallopian tube has 4 parts:

1) uterine, which is enclosed in the thickness of the uterine wall;

2) the isthmus of the fallopian tube - the narrowest and at the same time the thickest part of the tube, which is located between the leaves of the broad ligament of the uterus;

3) the ampulla of the fallopian tube, which accounts for almost half the length of the entire fallopian tube;

4) a funnel with the utricle of the pipe, which ends in long and narrow fimbriae of the pipe.

Through the openings of the fallopian tubes, the uterus and vagina, the peritoneal cavity in women communicates with external environment. Therefore, in case of non-compliance hygienic conditions infection may enter the internal genital organs and the peritoneal cavity of a woman.

The wall of the fallopian tube is formed by:

1) mucous membrane covered with single-layer ciliated epithelium;

2) smooth muscle membrane, represented by the outer longitudinal and inner circular (circular) layers;

3) serous membrane - part of the peritoneum that forms the broad ligament of the uterus,

G. Vagina- This is the organ of copulation. It is an extensible muscular-fibrous tube 8-10 cm long, with a wall thickness of about 3 mm. The upper end of the vagina starts from the cervix, goes down, penetrates through the urogenital diaphragm and the lower end opens into the vestibule with the opening of the vagina. In girls, the vaginal opening is closed by the hymen, the attachment point of which separates the vestibule from the vagina. The hymen is a semilunar or perforated plate of the mucous membrane. During the first sexual intercourse, the hymen is torn, and its remains form flaps of hymen. Rupture of the hymen (defloration) is accompanied by slight bleeding.

In front of the vagina are the bladder and urethra, and behind is the rectum. The vaginal wall consists of three membranes:

1) external - adventitia, built from loose connective tissue containing a large number of elastic fibers;

2) middle - smooth muscle, represented predominantly by longitudinally oriented bundles of muscle cells, A also with beams having a circular direction;

3) internal - mucous membrane, covered with non-keratinizing stratified squamous epithelium and devoid of glands. The mucous membrane is quite thick (about 2 mm), forms numerous transverse folds - vaginal folds (wrinkles). These folds on the anterior and posterior walls of the vagina form longitudinal ridges - the anterior and posterior columns of the folds.

The cells of the surface layer of the epithelium of the mucous membrane are rich in glycogen, which, under the influence of microbes living in the vagina, breaks down to form lactic acid. This gives vaginal mucus an acidic reaction and makes it bactericidal against pathogenic microbes. The vaginal epithelium continues to the vaginal part of the cervix. The walls of the vagina cover the latter, forming around it a narrow slit-like vaginal vault, the posterior part of which is deeper.

Inflammation of the ovary is called oophoritis, the uterine mucosa is called endometritis, the fallopian tube is called salpingitis, and the vagina is called vaginitis (colpitis).

The external female genitalia are located in the anterior perineum in the area of the genitourinary triangle and include the female genital area and the clitoris.

A. To the female genital area include the mons pubis, labia majora and minora, vestibule of the vagina, major and minor glands of the vestibule and bulb of the vestibule.

1) Pubis at the top it is separated from the abdominal area by the pubic groove, and from the hips by the coxofemoral grooves. The pubis (pubic eminence) is covered with hair that continues onto the labia majora. In the pubic area, the subcutaneous fat layer is well developed.

2) Labia majora They are a rounded paired skin fold 7-8 cm long, 2-3 cm wide, containing a large amount of adipose tissue. The labia majora limit the genital fissure from the sides and are connected to each other by the anterior (in the pubic area) and posterior (in front anus) lip commissures.

3) Labia minora- paired longitudinal thin skin folds. They are located more medially and hidden in the genital fissure between the labia majora, limiting the vestibule of the vagina. The labia minora are built of connective tissue without fatty tissue, contain a large number of elastic fibers, muscle cells and venous plexuses. The posterior ends of the labia minora are connected to each other by a transverse fold - the frenulum of the labia, and the upper ends form a frenulum and extreme

The human urinary system is an organ where blood is filtered, waste is removed from the body, and some hormones and enzymes are produced. The structure, diagram, and features of the urinary system are studied at school during anatomy lessons, and in more detail at a medical school.

Main functions

The urinary system includes such organs of the urinary system as:

ureters;
urethra.

The structure of the human urinary system is the organs that produce, accumulate and excrete urine. The kidneys and ureters are components of the upper urinary tract (UTT), and the bladder and urethra are lower parts urinary system.

Each of these bodies has its own tasks. The kidneys filter the blood, removing harmful substances from it and producing urine. The urinary system, which includes the ureters, bladder, and urethra, forms the urinary tract, which acts as a sewage system.

The urinary tract carries urine out of the kidneys, storing it and then removing it during urination. The structure and functions of the urinary system are aimed at effectively filtering the blood and removing waste from it. In addition, the urinary system and skin, as well as the lungs and internal organs maintain homeostasis of water, ions, alkali and acid, blood pressure, calcium, red blood cells. Maintaining homeostasis is urinary system.

important

The development of the urinary system from an anatomical point of view is inextricably linked with the reproductive system. That is why the human urinary system is often referred to as the genitourinary system.

Anatomy of the urinary system The structure of the urinary tract begins with the kidneys. This is the name given to the paired bean-shaped organ located in the back of the abdominal cavity. The kidneys' job is to filter waste, excess ions and chemical elements

in the process of urine production.

The left kidney is slightly higher than the right because the liver on the right side takes up more space. The kidneys are located behind the peritoneum and touch the back muscles. They are surrounded by a layer of adipose tissue that holds them in place and protects them from injury.

The bladder is a hollow organ that serves as a temporary container for urine. It is located along the midline of the body at the lower end of the pelvic cavity. During urination, urine slowly flows into the bladder through the ureters. As the bladder fills, its walls stretch (they can hold from 600 to 800 mm of urine).

The urethra is the tube through which urine exits the bladder. This process is controlled by the internal and external sphincters of the urethra. At this stage, the woman's urinary system is different. The internal sphincter in men consists of smooth muscles, while in the woman's urinary system there are none. Therefore, it opens involuntarily when the bladder reaches a certain degree of distension.

A person feels the opening of the internal sphincter of the urethra as a desire to empty the bladder. The external urethral sphincter consists of skeletal muscles and has the same structure in both men and women and is controlled voluntarily. A person opens it with an effort of will, and at the same time the process of urination occurs. If desired, a person can voluntarily close this sphincter during this process. Then urination will stop.

How does filtering work?

One of the main tasks performed by the urinary system is blood filtration. Each kidney contains a million nephrons. This is the name given to the functional unit where blood is filtered and urine is produced. Arterioles in the kidneys deliver blood to structures consisting of capillaries that are surrounded by capsules. They are called renal glomeruli.

As blood flows through the glomeruli, most of the plasma passes through the capillaries into the capsule. After filtration, the liquid part of the blood from the capsule flows through a number of tubes that are located near the filter cells and surrounded by capillaries. These cells selectively absorb water and substances from the filtered liquid and return them back to the capillaries.

Simultaneously with this process, metabolic wastes present in the blood are released into the filtered part of the blood, which at the end of this process turns into urine, which contains only water, metabolic wastes and excess ions. At the same time, the blood that leaves the capillaries is absorbed back into the circulatory system along with nutrients, water, ions that are necessary for the functioning of the body.

Accumulation and release of metabolic waste

The krin produced by the kidneys passes through the ureters into the bladder, where it is collected until the body is ready to empty itself. When the volume of fluid filling the bladder reaches 150-400 mm, its walls begin to stretch, and receptors that respond to this stretch send signals to the brain and spinal cord.

From there comes a signal aimed at relaxing the internal sphincter of the urethra, as well as a feeling of the need to empty the bladder. The process of urination can be delayed by an effort of will until the bladder is inflated to its maximum size. In this case, as it stretches, the number of nerve signals will increase, which will lead to more discomfort and a strong desire to stool.

The process of urination is the release of urine from the bladder through the urethra. In this case, urine is removed outside the body.

Urination begins when the urethral sphincter muscles relax and urine exits through the opening. Simultaneously with the relaxation of the sphincters, the smooth muscles of the bladder walls begin to contract to force urine out.

Features of homeostasis

The physiology of the urinary system is that the kidneys maintain homeostasis through several mechanisms. At the same time, they control the release of various chemicals in the body.

The kidneys can control the release of potassium, sodium, calcium, magnesium, phosphate and chloride ions into the urine. If the level of these ions exceeds the normal concentration, the kidneys may increase their excretion from the body to maintain normal levels of electrolytes in the blood. Conversely, the kidneys can retain these ions if their levels in the blood are lower than normal. During blood filtration, these ions are reabsorbed into the plasma.

The kidneys also ensure that the levels of hydrogen ions (H+) and bicarbonate ions (HCO3-) are in balance. Hydrogen ions (H+) are produced as a natural by-product of dietary protein metabolism and accumulate in the blood over time. The kidneys send excess hydrogen ions into the urine for removal from the body. In addition, the kidneys reserve bicarbonate ions (HCO3-), in case they are needed to compensate positive ions hydrogen.

The growth and development of body cells requires isotonic fluids to maintain electrolyte balance. The kidneys maintain osmotic balance by controlling the amount of water that is filtered and removed from the body through urine. If a person uses a lot amount of water, the kidneys stop the process of reabsorption of water. In this case, excess water is excreted in the urine.

If body tissues are dehydrated, the kidneys try to return as much as possible to the blood during filtration. Because of this, the urine is very concentrated, with a lot of ions and metabolic waste. Changes in water excretion are controlled by antidiuretic hormone, which is produced in the hypothalamus and anterior pituitary gland to retain water in the body when there is a lack of water.

The kidneys also monitor the level of blood pressure, which is necessary to maintain homeostasis. When it rises, the kidneys lower it, reducing the amount of blood in the circulatory system. They can also reduce blood volume by reducing the reabsorption of water into the blood and producing watery, dilute urine. If blood pressure becomes too low, the kidneys produce the enzyme renin, which constricts blood vessels. circulatory system and produce concentrated urine. At the same time, more water remains in the blood.

Hormone production

The kidneys produce and interact with several hormones that control various body systems. One of them is calcitriol. This active form vitamin D in the human body. It is produced by the kidneys from precursor molecules that appear in the skin after exposure to ultraviolet radiation. solar radiation.

Calcitriol works together with parathyroid hormone, increasing the amount of calcium ions in the blood. When their levels fall below a threshold level, the parathyroid glands begin to produce parathyroid hormone, which stimulates the kidneys to produce calcitriol. The effect of calcitriol is that the small intestine absorbs calcium from food and transfers it into the circulatory system. In addition, this hormone stimulates osteoclasts in bone tissue skeletal system to the breakdown of the bone matrix, which causes the release of calcium ions into the blood.

Another hormone produced by the kidneys is erythropoietin. The body needs it to stimulate the production of red blood cells, which are responsible for transporting oxygen to tissues. At the same time, the kidneys monitor the state of the blood flowing through their capillaries, including the ability of red blood cells to carry oxygen.

If hypoxia develops, that is, the oxygen content in the blood drops below normal, the epithelial layer of the capillaries begins to produce erythropoietin and releases it into the blood. Through the circulatory system, this hormone reaches the red bone marrow, in which it stimulates the rate of red blood cell production. Thanks to this, the hypoxic state ends.

Another substance, renin, is not a hormone in the strict sense of the word. This is an enzyme that the kidneys produce to increase blood volume and pressure. This usually occurs as a reaction to blood pressure falling below a certain level, blood loss, or dehydration, such as increased skin sweating.

Importance of diagnosis

Thus, it is obvious that any malfunctions in the urinary system can lead to serious problems in the body. There are a variety of pathologies of the urinary tract. Some may be asymptomatic, others may be accompanied by various symptoms, including abdominal pain when urinating and various secretions in urine.

Most common reasons pathologies are infections of the urinary system. The urinary system in children is especially vulnerable in this regard. The anatomy and physiology of the urinary system in children proves its susceptibility to disease, which is aggravated by insufficient development of the immune system. At the same time, even a healthy child’s kidneys work much worse than those of an adult.

To prevent development serious consequences, doctors recommend taking a general urine test every six months. This will allow timely detection of pathologies in the urinary system and treatment.

2pochku.ru

The work of cells leads to the formation of harmful substances that the body needs to eliminate. This problem is solved by absorbing some substances for reuse and removing others. Removal of harmful products is carried out in four ways: by breathing, with sweat, with feces and with the help of the urinary system. The latter is actually excretory system, consisting of a complex organ - the kidneys, as well as the ureters, bladder and urethra.

The urinary, or excretory, system filters the blood and removes metabolic products (metabolism), that is, products resulting from the transformations that the eaten food undergoes before it is converted into digestible substances. In this way, the cells receive the necessary energy to perform their functions, and harmful substances enter the kidneys through the blood.

Organs of the urinary system

Kidneys- they filter the blood and form urine from water and harmful substances, which is removed from the body through the urinary system.

Each kidney has the following parts:

Outer shell: covers the kidney, has a whitish color.

Cortex: peripheral part, smooth, yellowish in color.

Brain matter: inner part reddish in color. It consists of 10 or 12 pyramidal formations, the Malpighi pyramids, the apexes or papillae of which face the inside of the kidney.

Pelvis: The part of the kidney that communicates with the ureter is a reservoir in which small sacs are located - the pelvis, which collects urine coming out of the papillae.

Adrenal glands: not part of the kidney, it is endocrine glands, that is, glands that produce hormones such as cortisol (mainly regulating the metabolism of carbohydrates, fats and proteins) and adrenaline (regulating the functioning of the heart and the dilation and contraction of blood vessels).

Nephron is functional unit kidneys (there are more than a million of them in each kidney). Each nephron contains numerous blood vessels, which branch into thin capillaries. Each capillary network surrounds a spherical body 0.1-0.2 mm in size, called the Malpighi glomerulus, covered with a membrane, or Shumlyansky-Bowman capsule.

Blood enters the capsule through a small artery and disperses through the network of blood capillaries of the glomerulus. Through the thinnest walls of the capillaries, the blood is freed from water and harmful substances.

Clean, filtered blood is collected in increasingly larger veins and flows into renal vein, and from there - into the inferior vena cava. Water and breakdown products pass through the thin capsule of Shumlyansky-Bowman and enter the canal emerging from the glomerulus - the proximal convoluted tubule (here: reabsorption, reabsorption of glucose, proteins, metal ions), pass the tortuous section, or loop of Henle (primary urine passes ), and continue to move along the distal convoluted tubule (secondary urine), which flows into a wider duct - the collecting duct.

The collecting ducts are connected to each other in pyramids, forming the mammillary tubules, and carry urine to the edges of the papillae; products to be excreted are collected in the renal pelvis, from where they descend through the ureter into the bladder.

Ureters- canals connecting the kidneys to the bladder.

The body gets rid of harmful substances through the system of excretory ducts, or urinary organs. The ureters, the initial organ of the urinary system, are two tubes 25-30 cm long that connect each of the kidneys to the bladder.

Its walls consist of two layers:

Mucous layer: lines their inside.

Muscle layer: Smooth muscle tissue allows the ureter to contract and, through peristaltic movements, propels urine towards the bladder. The upper end of the ureter is a continuation of the renal pelvis, and the lower end communicates with the bladder, where urine accumulates.

Bladder- an elastic muscular organ in which urine coming from the kidneys accumulates.

The muscle tissue of which it is composed gives it elasticity, allowing it to hold a large volume of urine, approximately 300-350 cm3.

The bladder has two muscles called sphincters that keep urine from leaving until the bladder is full. One of them is located inside the bladder, around the opening of the urethra, and the other is located in the urethra itself, 2 cm below. We can compress this second, or external, sphincter voluntarily.

The expansion of the bladder when it is full causes the muscle to contract and the internal sphincter to relax. If you voluntarily relax the external constrictor, urine will begin to flow through the urethra.

Urethra(urethra) is a channel through which urine accumulated in the bladder is removed from the body.

♀— 3-4 cm, 1 sphincter

♂— urethra + seminiferous tubules, prostate gland covers the canal from above, 2 sphincters

PATHOLOGIES

Glamerulonephritis(inflammation of the glomeruli of the kidneys)

Acute (2-3 months)

Subacute (6 months)

Chronic

intracapillary (inside capillaries)
mesengal
extracapillary (not capillary-capsule)

Infection (complications after tonsillitis, viral diseases, injuries) -> part of the glomerulus-hilum -> disruption or cessation of the glomerulus -> disruption of the filtration function -> part of the pelvis and loops of Henley do not work -> necessary substances are excreted with secondary urine

(treatment: artificial kidney, hemodelysis (artificial filtration))

2) Pyelonephritis(ascending pyelonephritis) – inflammation of the pelvis and nephron

flora -> through the urethra -> into the bladder - cystitis(3) (inflammation of the bladder) -> through the ureters -> into the pelvis – pyelitis(4) (inflammation of the pelvis) -> pilonephritis

inflammation of the capillaries at the loop of Henley -> disruption of the capillaries -> disruption of reabsorption

necessary for development Vesicoureteral reflux(5)

(promotes the spread of microorganisms from the bladder to the kidneys. The disorder occurs at the point where the ureter enters the bladder. Normally, it enters the bladder in an oblique direction, at an acute angle to the surface of the mucosa, therefore, when the bladder wall contracts during urination, the opening of the ureter is pinched. In patients with vesicoureteral reflux, the final section of the ureter is short and oriented at approximately 90° to the surface of the mucous membrane; this leads to the fact that during urination the opening of the ureter does not close and urine under pressure enters the ureters from the bladder. Reflux of urine into the kidneys leads to an increase. intrapelvic pressure, however, intraparenchymal reflux is a decisive factor in the development of pyelonephritis. For intraparenchymal reflux, the main significance is the change in the configuration of the papillae, the main number of which is found at the poles of the kidneys, where more pronounced damage is observed.)

6) Chronic pyelonephritis

develops against the background chronic renal failure(7)

Tumors(mainly from glomerular epithelial cells)

9) Kidney stone disease

violation of water-salt metabolism

inflammation

stagnation of urine

desquamation of pelvic epithelial cells

single

multiple

caraloid

with stagnation of urine -> bend of the uterus

endometritis – inflammation of the endometrium of the uterus

fibroids, fibroids -> decreased elasticity

inflammation of the epididymis

Archites(testicular inflammation)

studfiles.net

Anatomy, histology, physiology

Every person has two ureters - right and left. This tubular organ passes through the retroperitoneum. It is a duct running from the renal pelvis to the bladder. Passing through the wall of the bladder, it opens into internal cavity estuaries. The length of the duct is about 30 centimeters, and the diameter varies between 4-15 mm. This organ cannot be felt through the abdomen.

The ureter consists of three parts:

Intramural - lies in the wall of the bladder.
The pelvic region is located from the small pelvis to the bladder.
Abdominal - stretches from the pelvis and ends at the entrance to the pelvis.

The ureters perform important functions. First of all, they remove urine from the kidneys to the bladder. This process is triggered by involuntary muscle contraction. Alternately from each ureter, at intervals of 15-20 seconds, the waste fluid descends into the bladder in small portions. Another important function of paired organs with a tubular structure is to block the reverse flow of urine during urination.

4 main symptoms of ureteral diseases

Based on the nature of the manifestations, one or another disease can be identified:

Stones – acute pain in the lower back that does not go away completely; after changing body position there is no relief, frequent urge to urination.
Inflammatory processes - the outflow of urine is obstructed, the urine is cloudy, high blood pressure, cramping pain in the lumbar region
Damage due to injury or unsuccessful operation– urine with blood and urine discharge from the wound is observed when open form, at closed injury In addition to the previously mentioned symptoms, a few days after the injury, the temperature rises and swelling appears in the lumbar region.
Congenital pathologies - cystitis, narrowing of the walls of the ureter, problems with urine excretion. If the organ has not developed correctly or is not there at all, there is a possibility of death.

Ureteral diseases

There are two types of pathologies - congenital, caused by intrauterine damage to the fetus, and acquired, usually the cause is obstruction. Most common congenital disorder- complete doubling of the organ, when the ureters open into the cavity of the bladder with two mouths, or partial - the ureter doubles in certain areas and opens with one mouth. Triplication also occurs, sometimes only one ureter develops, and the second is absent. Another type of pathology is atony. The walls of the ureter are thin, and it itself is dilated. In this case, urine passes through the duct with a delay.

A common disease of the genitourinary system is urolithiasis. Stones can descend from the affected kidney and clog the sections of the ureter located below. They often pass through ducts into the bladder or urethra. The formation of stones can be promoted by poor diet, sedentary lifestyle, or insufficient fluid intake. Another common disorder is ureterocele, in which the cystic opening of the duct narrows and the orifice protrudes.

A rupture of the ureter can be a consequence of injury - a fall, a blow with a blunt object, or sudden compression of the torso area. Closed type injuries are most often observed. If this organ is injured, immediate surgical intervention is required.

Research methods

Modern diagnostic methods are used to examine the ureters:

Urine collection and blood test - allows you to identify leukocytes, proteins or red blood cells, the presence of which indicates the presence of pathologies.
Cystoscopy - the procedure is performed using a cystoscope - a special device, which is a tube with a lighting device. The ureteral orifices are examined. To obtain accurate results, a rigid cystoscope is used; surgery using a flexible device is less painful. The procedure is performed under local anesthesia. The advantage of cystoscopy is that it is possible not only to diagnose, but also to remove tumors or crush stones.
Excretory urography - a contrast agent is injected intravenously, after which an X-ray of the urinary tract and kidneys is taken. This operation based on the ability of the kidneys to remove contrast agents from the blood. This method allows you to detect radiopaque stones.
Retrograde urethrography - used to examine the urethra, used mainly for men. First, they do it on an X-ray table overview shot to detect tumors and stones. A contrast agent is injected into the urethra to dislodge air bubbles. Next, a catheter is inserted and images are taken. Ultrasound is a painless procedure that can detect stones or wall thickening.

Treatment

In case of damage or congenital pathology of the ureter, it is required surgical intervention. In most cases it is suitable for patients with urethritis traditional treatment. To remove stones, stone dissolving drugs are prescribed. Depending on the type of stones, a diet is selected that will reduce the likelihood of their formation. If the inflammatory process is caused by an infection, a course of antibiotic therapy is prescribed.

If they develop adhesive processes, bougienage is carried out. This operation involves inserting a special rod through the urinary canal. Stones are removed by ultrasonic crushing. When the stone grows, surgery is often required. In this case, part of the ureter is removed along with the stone. In some cases it is required complete removal organ.

pochkam.ru

1. Overview of the urinary organs and the importance of the urinary system.

3. Ureters.

4. Bladder and urethra.

OBJECTIVE: To know the topography, structure and functions of the kidneys, ureters, bladder and urethra. To be able to show the organs of the urinary system and their parts on posters, dummies and tablets.

1. The urinary system is a system of organs that excrete metabolic end products and remove them from the body to the outside. The urinary and genital organs are related to each other in development and location, therefore they are combined into the genitourinary system. The branch of medicine that studies the structure, function and diseases of the kidneys is called nephrology, diseases of the urinary (and in men, the genitourinary) system is called urology.

In the process of the body's vital activity, during metabolism, end products of decomposition are formed that cannot be used by the body, are toxic to it and must be excreted. Most of the decomposition products (up to 75%) are excreted in urine by the urinary organs (the main organs of excretion) . The urinary system includes: kidneys, ureters, bladder, urethra. The formation of urine occurs in the kidneys; the ureters serve to remove urine from the kidneys to the bladder, which serves as a reservoir for its accumulation. Urine is periodically discharged through the urethra.

The kidney is a multifunctional organ. While performing the function of urine formation, it simultaneously participates in many others. Through the formation of urine, the kidneys: 1) remove the final (or by-products) of metabolism from the plasma: urea, uric acid, creatinine; 2) control the levels of various electrolytes throughout the body and plasma: sodium, potassium, chlorine, calcium, magnesium; 3) remove foreign substances that have entered the blood: penicillin, sulfonamides, iodides, paints; 4) help regulate the acid-base state (pH) of the body, establishing the level of bicarbonates in the plasma and removing acidic urine; 5) control the amount of water, osmotic pressure in the plasma and other areas of the body and thereby maintain homeostasis (Greek homoios -like; stasis - immobility, state), i.e. relative dynamic constancy of the composition and properties of the internal environment and the stability of the basic physiological functions of the body; 6) participate in the metabolism of proteins, fats and carbohydrates: they break down altered proteins, peptide hormones, glyconeogenesis; 7) produce biologically active substances: renin , involved in maintaining blood pressure and circulating blood volume, and erythropoietin, which indirectly stimulates the formation of red blood cells.

In addition to the urinary organs, the skin, lungs and digestive system have excretory and regulatory functions. The lungs remove carbon dioxide and water from the body, the liver secretes bile pigments into the intestinal tract; Some salts (iron and calcium ions) are also excreted through the digestive canal. The sweat glands of the skin serve to regulate body temperature by evaporating water from the surface of the skin, but at the same time they also secrete 5-10% of metabolic products such as urea, uric acid, creatinine. Sweat and urine are qualitatively similar in composition, but in sweat the corresponding components are contained in much lower concentrations (8 times).

2. Kidney (Latin hep; Greek nephros) is a paired organ located in the lumbar region on the posterior wall of the abdominal cavity behind the peritoneum at the level of the XI-XII thoracic and I-III lumbar vertebrae. The right kidney lies below the left. Each bud is shaped like a bean, measuring 11x5 cm, weighing 150 g (from 120 to 200 g). There are anterior and posterior surfaces, upper and lower poles, medial and lateral edges. On the medial edge there are the renal hilum, through which the renal artery, vein, nerves, lymphatic vessels and ureter pass. The hilum of the kidney continues into a recess surrounded by the substance of the kidney - the renal sinus.

The kidney is covered with three membranes. The outer shell is the renal fascia, consisting of two layers: prerenal and retrorenal. Anterior to the prerenal layer is the parietal (parietal) peritoneum. Under the renal fascia lies a fatty membrane (capsule) and even deeper is the lining of the kidney - the fibrous capsule. From the latter, outgrowths extend into the kidney - septa, which divide the substance of the kidney into segments, lobes and lobes. Vessels and nerves pass through the septa. The membranes of the kidney, together with the renal vessels, are its fixing apparatus, therefore, when it is weakened, the kidney can even move into the small pelvis (vagal kidney).

The kidney consists of two parts: the renal sinus (cavity) and the renal substance. The renal sinus is occupied by small and large renal calyces, the renal pelvis, nerves and vessels surrounded by fiber. There are 8-12 small cups, they have the shape of glasses, covering the projections of the renal substance - the renal papillae. Several small renal calyces, merging together, form large renal calyces, of which there are 2-3 in each kidney. The large renal cups, connecting, form a funnel-shaped renal pelvis, which, tapering, passes into the ureter. The wall of the renal calyces and renal pelvis consists of a mucous membrane covered with transitional epithelium, smooth muscle and connective tissue layers.

The renal substance consists of a connective tissue base (stroma), represented by reticular tissue, parenchyma, vessels and nerves. The parenchyma substance has 2 layers: the outer one is the cortex, the inner one is the medulla. The renal cortex forms not only its surface layer, but also penetrates between areas medulla, forming renal columns. The main part (80%) of the structural and functional units of the kidneys—nephrons—is located in the cortex. Their number in one kidney is about 1 million, but only 1/3 of the nephrons function at the same time. The medulla contains 10-15 cone-shaped pyramids, consisting of straight tubules that form a nephron loop, and collecting ducts that open into the cavity of the small renal calyces. Urine formation occurs in the nephrons. In each nephron, the following sections are distinguished: 1) renal (Malpighian) corpuscle, consisting of the vascular glomerulus and the surrounding double-walled capsule of A.M. Shchumlyansky-V. Bowman; 2) convoluted tubule of the first order - proximal, passing into the descending section of the loop F. Henle; 3) thin bend of the loop of F. Henle; 4) convoluted tubule of the second order - distal. It flows into the collecting ducts - straight tubules that open on the papillae of the pyramids into the small renal calyces. The length of the tubules of one nephron is 20 -50 mm, and total length of all tubules in two kidneys is 100 km.

The renal corpuscles, proximal and distal convoluted tubules are located in the renal cortex, the loop of Henle and collecting ducts are in the medulla. About 20% of nephrons, called juxtamedullary nephrons, are located at the border of the cortex and medulla. They contain cells that secrete renin and erythropoietin, which enter the blood ( endocrine function kidneys), therefore their role in urine formation is insignificant.

Features of blood circulation in the kidney: 1) blood passes through a double capillary network: the first time in the capsule of the renal corpuscle (the vascular glomerulus connects two arterioles: afferent and efferent, forming a wonderful network), the second time on the convoluted tubules of the 1st and 2nd order (typical network) between arterioles and venules; 2) the lumen of the efferent vessel is 2 times narrower than the lumen of the afferent vessel; therefore, less blood flows out of the capsule than it enters; 3) the pressure in the capillaries of the vascular glomerulus is higher than in all other capillaries of the body. (70-90 mmHg vs. 25-30 mmHg).

The endothelium of the glomerular capillaries, flat epithelial cells (podocytes) of the inner layer of the capsule and the three-layer basement membrane common to them constitute a filtration barrier through which plasma components are filtered from the blood into the capsule cavity, forming primary urine.

3. The ureter (ureter) is a paired organ, a tube 30 cm long, 3-9 mm in diameter. The main function of the ureter is to drain urine from the renal pelvis into the bladder. Urine moves through the ureters due to rhythmic peristaltic contractions of its thick muscular lining. From the renal pelvis, the ureter goes down the posterior abdominal wall, approaches the bottom of the bladder at an acute angle, obliquely pierces its posterior wall and opens into its cavity.

Topographically, the ureter is divided into abdominal, pelvic and intramural (a 1.5-2 cm long section inside the bladder wall) parts. Three bends are distinguished in the ureter: in the lumbar, pelvic regions and before entering the bladder, as well as three narrowings: at the the transition of the pelvis to the ureter, at the transition of the abdominal part to the pelvic part and before the flow into the bladder.

The wall of the ureter consists of three membranes: the inner - mucous (transitional epithelium), the middle - smooth muscle (in the upper part it consists of two layers, in the lower - three) and the outer - adventitia (loose fibrous connective tissue). The peritoneum covers the ureters, like the kidneys, only in front; these organs lie retroperitoneal (retroperitoneal).

4. The bladder (vesica urinaria; Greek cystis) is an unpaired hollow organ for storing urine, which is periodically excreted from it through the urethra. The capacity of the bladder is 500-700 ml, the shape changes depending on the filling with urine: from flattened to ovoid. The bladder is located in the pelvic cavity behind the pubic symphysis, from which it is separated by a layer of loose tissue. When the bladder fills with urine, its tip protrudes and comes into contact with the anterior abdominal wall. The posterior surface of the bladder in men is adjacent to the rectum, seminal vesicles and ampoules of the vas deferens, in women - to the cervix and vagina (their anterior walls).

In the bladder there are: 1) the apex of the bladder - the anterosuperior pointed part facing the anterior abdominal wall; 2) the body of the bladder - the middle most part of it; 3) the bottom of the bladder - facing downwards and backwards; 4) the neck of the bladder - the narrowed part of the bottom of the bladder .

At the bottom of the bladder there is a triangular-shaped area - the vesical triangle, at the tops of which there are 3 openings: two ureteric and the third - the internal opening of the urethra.

The wall of the bladder consists of three membranes: inner - mucous (stratified transitional epithelium), middle - smooth muscle (two longitudinal layers - outer and internal and middle - circular) and outer - adventitial and serous (partially). The mucous membrane together with the submucosa forms folds, with the exception of the bladder triangle, which does not have them due to the absence of a submucosa there. In the area of the neck of the bladder at the beginning of the urethra, a circular (circular) layer of muscle forms a constrictor - the sphincter of the bladder, which contracts involuntarily . The muscular membrane, contracting, reduces the volume of the bladder and expels urine out through the urethra. Due to the function of the muscular lining of the bladder, it is called the muscle that pushes urine out (detrusor). The peritoneum covers the bladder from above, from the sides and from behind. The filled bladder is located mesoperitoneally in relation to the peritoneum; empty, collapsed - retroperitoneal.

The urethra (urethra) in men and women has large morphological gender differences.

The male urethra (urethra masculina) is a soft elastic tube 18-23 cm long, 5-7 mm in diameter, which serves to remove urine from the bladder to the outside and seminal fluid. It begins with the internal opening and ends with the external opening located on the head of the penis. Topographically, the male urethra is divided into 3 parts: the prostatic part, 3 cm long, located inside the prostate gland, the membranous part, up to 1.5 cm, lying in the area of the pelvic floor from the apex of the prostate gland to the bulb of the penis, and the spongy part, 15-20 cm long, passing inside the corpus spongiosum of the penis. In the membranous part of the canal there is a voluntary sphincter of the urethra made of striated muscle fibers.

The male urethra has two curvatures: anterior and posterior. The anterior curvature straightens when the penis is raised, while the posterior one remains fixed. In addition, along its path, the male urethra has 3 narrowings: in the area of the internal opening of the urethra, when passing through the urogenital diaphragm and at the external opening. Enlargements of the lumen of the canal are present in the prostate part, in the bulb of the penis and in its final section - the scaphoid fossa. The curvature of the canal, its narrowing and expansion are taken into account when inserting a catheter to remove urine. The mucous membrane of the prostatic part of the urethra is lined with transitional epithelium, the membranous and spongy parts are multi-row prismatic, and in the area of the head of the penis - multi-layered squamous with signs of keratinization. In urological practice, the male urethra is divided into an anterior one, corresponding to the spongy part of the canal, and a posterior one, corresponding to the membranous and prostatic parts.

The female urethra (urethra feminina) is a short, slightly curved and backward-facing tube, 2.5-3.5 cm long, 8-12 mm in diameter. It is located in front of the vagina and is fused with its anterior wall. It starts from the bladder with the internal opening of the urethra and ends with the external opening, which opens anteriorly and above the opening of the vagina. At the point where it passes through the urogenital diaphragm there is an external urethral sphincter, consisting of striated muscle tissue and contracting voluntarily. The wall of the female urethra is easily extensible. It consists of mucous and muscular membranes. The mucous membrane of the canal near the bladder is covered with transitional epithelium, which then becomes multilayered squamous non-keratinizing with areas of multirow prismatic. The muscular layer consists of bundles of smooth muscle cells that form 2 layers: the inner longitudinal and outer circular.

One of the most important conditions for the life of each organism is the constancy of the environment inside it, this also includes the water content in the body and the ratio of its volumes. These parameters are controlled by the urinary system in the human body. The bladder and ureters are components of the urinary system.

First, urine is secreted from the kidneys, then it enters the renal calyces into the renal pelvis. Further, urine moves through the ureter, and then moves into the bladder. From the bladder, as it fills, urine comes out through the urethra, which has a different structure in women and men.

What is the function of the bladder?

The bladder is an organ that is shaped like a ball. The organ's task is to accumulate and store urine without leaking, as well as further excretion of urine when the bladder is full. Most people have bowel movements four to eight times a day without getting up at night.

The walls of the bladder are covered with connective tissue and smooth muscles. Connective tissue is very elastic and can contract and relax repeatedly. The wall of the bladder has four layers. The first is the internal one, which is called the urothelium. This is a slimy layer. Beneath it is the submucosal layer. It is supplied with many nerves, blood vessels, and connective tissue. Next is a layer of muscle tissue, which is very smooth. The last layer is called the surface layer. The inner layer consists of a large number of fibers that can stretch when the bladder is full of urine. The bladder fills, stores urine and then releases it.

What is the function of the bladder? The function of the bladder is also the nervous system, which is represented by the spinal cord, brain, and peripheral nerves. It is also of great importance in maintaining bladder function. When the bladder is full, it nerve endings send signals to the brain and report that it is time to empty the bladder. And the brain, in turn, gives the opposite signal and the desire to urinate appears. And when a person is ready to urinate, the brain begins to progressively send signals to the muscles pelvic floor about the need to relax and remove urine. Then it enters the bladder nerve impulse, and it contracts and removes urine.

If the function of the bladder and its control are impaired, then the person experiences “urinary incontinence.” This occurs in approximately 80% of patients suffering from multiple sclerosis. With this disease, signals to the brain arrive slowly and intermittently. Accordingly, the impulses that arrive to the pelvic muscles also slow down. The most common bladder dysfunction is urgency. In this case, people experience a feeling of tension and pressure in the bladder and a frequent urge to urinate. The nerve signals that coordinate the function of urine production begin to become distorted, and the person feels an urgent need to go to the toilet.

The bladder and ureters are components of the urinary system

Cylindrical tubes, the diameter of which is about 6-8 millimeters, are the human ureters. The ureters are characterized by rapid growth; in the first few years of a person’s life, their length doubles. The ureters come into contact with the bladder through its wall. Rhythmic peristaltic contractions move urine through the ureters. The membrane of the ureter is folded and is lined with transitional epithelium.

The bladder is located behind the pubic symphysis. The basis for the wall of this bladder is made up of smooth muscles, located in several layers and intertwined with each other. The most developed is the circular layer, which forms the bladder constrictor in the area of the urethral opening. A person also has a striated external constrictor for the urethra.

Kidneys - components of the urinary system

A paired organ called the kidney is also part of the urinary system. This body at in good condition covered with connective tissue and a special serous membrane. The kidney is divided into several parts: the medulla and the cortex. Only from the renal artery can blood flow into the kidney, which is a branched canal of interlobar and interlobular arteries. Special afferent arterioles depart from them, which supply the glomeruli with blood. The main function of the kidneys is to circulate blood.

The human urinary system is represented by the kidneys, ureters, urethra and bladder.

Main functions of the system:

Release of metabolic products;
Maintaining water-salt balance in the body;
Hormonal function due to biologically active substances synthesized by the adrenal glands.

It should be noted that the functions of excreting and maintaining homeostasis are vital.

Bud

Kidney is parenchymal organ bean-shaped, consisting of cortical and medulla layers. .

WITH inside blood vessels (inferior vena cava and aorta) enter the kidney through the renal gate. In turn, the ureters emerge from the kidneys in the same place.

On the outside, the organ is covered with fatty and connective tissue capsules.

The structural and functional unit of the kidney is the nephron - a collection of glomeruli and excretory tubules.

In general, the kidney is an organ that plays a major role in the detoxification process of the body. The remaining organs of the urinary system perform only the functions of storing and excreting urine.

Ureter

The ureter is a hollow tube with a length of up to 32 cm and a lumen thickness of up to 12 mm. The size of the ureter is purely individual and depends not only on a person’s height and build, but also on genetic factors. So, with developmental anomalies, the length may differ sharply from the indicated one.

The wall of the ureter has several layers:

Internal (mucous) – lined with multilayered transitional epithelium;
Medium (muscular) - muscle fibers are oriented in different directions;
The outer (adventitial) consists of connective tissue.
The function of the ureter is to remove urine from the kidneys by contracting muscle fibers and maintaining normal urodynamics.

M bladder

This is a hollow organ in which urine accumulates until the moment of urination. The signal for the urge to urinate is the volume of accumulated urine of 200 ml. Bladder capacity varies, but the average is 300-400 ml.

The bladder has a body, a bottom, an apex and a neck. Its shape changes depending on the degree of filling.

The wall on the outside is covered with a serous membrane, followed by a muscular (smooth muscle tissue), inside the bladder is lined with a mucous membrane consisting of transitional epithelium. In addition there is glandular epithelium and lymphatic follicles. The muscle tissue is not homogeneous and generally forms a detrusor, which has a narrowing closer to the bottom - the sphincter of the bladder.

Urethra

Immediately from the bladder, urine, under the influence of muscle contractions, enters the urethra. Further, through the urethra (sphincter), it is released into the environment.

The urethra, like the ureter, consists of three layers. The epithelium of the mucous membrane varies depending on the location. In the prostate area (in men), the mucous membrane of the urethra is covered with transitional epithelium, then with multilayer prismatic epithelium, and finally, in the head area with multilayered squamous epithelium. On the outside, the canal is covered with a muscular layer and connective tissue consisting of fibrous and collagen fibers.

It should be noted that in women it is shorter than in men, why women more susceptible to inflammatory diseases of the urogenital tract.

I offer you a visual video “Structure of the human urinary system”

Diseases of the urinary system

Diseases of all components of the urinary system can be infectious or congenital genetic. During an infectious process, specific structures become inflamed. Inflammation of other organs, as a rule, is less dangerous, but leads to unpleasant sensations: pain and pain.

Genetic diseases are associated with structural anomalies of a particular organ, usually anatomical. As a result of such disorders, the production and excretion of urine is difficult or impossible.

Genetic diseases include: In this case, instead of two kidneys, the patient may have one, two, or none at all (as a rule, such patients die immediately after birth). The ureter may be absent or may not open into the bladder. The urethra is also subject to developmental abnormalities.

Women are more likely than men to be at risk of contracting infectious agents because their urethra is shorter. Thus, the infectious agent can rise to higher organs in less time and cause inflammation.