The urinary system is the organs that form it. Structure of the organs of the urinary system

Structure and functions of the urinary system

Lesson using reference notes

Equipment: tables “Organs of excretion”, model “Structure of the kidney of a mammal”, filmstrip “Structure and function of the kidneys”.

DURING THE CLASSES

I. Consolidation of previously studied material

Three students working at the board.

Assignment for student 1: talk about metabolism in the body using the following diagram:

Basic Concepts

Homeostasis is the body’s ability to withstand environmental changes and maintain relative constancy of composition, as well as the intensity of physiological processes.

Metabolism– a set of metabolic processes and energy and their biochemical transformations in a living organism or a set of chemical transformations of compounds, characteristic of the cell, connected with each other and with environment and ensuring the vital activity of the cell.

Anabolism(or assimilation) – processes of synthesis of complex organic matter from simple ones. These processes are also called plastic exchange: Energy-rich cell substances - proteins, fats, carbohydrates - are formed from simple nutrients. These processes require energy.

Catabolism(or dissimilation) – processes of splitting complex organic substances into simple ones. These processes are also called energy metabolism: proteins, fats and carbohydrates are broken down and oxidized to inorganic substances. These processes are accompanied by the release of energy, which is spent on the synthesis of new substances, muscle movement, work internal organs, mental work, etc.

Teacher. Where do these processes take place?

Student. In a cage.

Teacher. What is needed for this?

Student. Involvement of enzymes.

Teacher. Is there a relationship between these processes?

Student. Yes. They occur simultaneously in the cell, with many of the end products of catabolism being the initial products of anabolism. The energy released during catabolism is consumed during anabolism.

Teacher. What laws of dialectics does the metabolic process obey?

Student. The law of conservation and transformation of energy, the law of unity and struggle of opposites.

Assignment to student 2: talk about the processes of isolation and characterize the types of these processes.

Basic concepts:

Defecation– removal of undigested food debris through the anus. These are not metabolic products, because undigested food does not enter the body cells and does not participate in metabolic processes. No energy is required to remove these residues.

Excretion– the release of substances that are not subject to further use in the body from cells and from the bloodstream through urine and sweat. Energy is consumed during excretion.

Secretion– the cell releases substances that are used within the body itself. For example, the release of enzymes in gastric juice or saliva. This consumes energy.

Assignment for the 3rd student: talk about the end products of the breakdown of the basic substances of the cell ( working with diagrams).

Teacher. What happens to the final products?

Student. Some are used by the body, others are removed into the external environment.

Teacher. How does this happen? After all, most cells are located deep in the body, and not on the border with the environment.

Student. All these substances enter the blood and are transported to the excretory organs.

Teacher. What organs are these?

Student. Lungs, kidneys, skin, intestines.

Teacher. To summarize, analyze the table.

Teacher. Define the selection process.

Student. Selection- This is the process of removing metabolic end products from the body, as well as removing excess water, salts and other substances.

Teacher. What organ systems is this process associated with?

Student. With urinary, circulatory, respiratory, skin, digestive.

II. Learning new material

Teacher. So, from the table. 1 it is clear that greatest number substances are eliminated through the kidneys. The kidneys are organs of the urinary system. We will get acquainted with the structure of this system and its functions in today's lesson.

The work is carried out in groups. Each group receives a task. The report on the work is drawn up in the form of a supporting summary in notebooks and on the board.

The main task is to establish the relationship between the functions and structure of the organs of the urinary system. Creative task: make Euler circles based on any fragment of the lesson.

Functions of the urinary system

Teacher's story.

1. Excretory (excretion) – removed:

a) end products of dissimilation;
b) excess water and salts;
c) toxic substances (alcohol, drugs);

2. Regulatory – ensures consistency:

a) the internal environment of the body (volume of blood, lymph and tissue fluid);
b) osmotic pressure - the kidneys regulate the concentration of salts in the blood and tissue fluid that washes the cells. If the concentration of salts in the liquid is greater than in the cell, water leaves it, the cell shrinks and dies (plasmolysis); and vice versa, if the concentration of salts in the liquid is less than in the cell, water enters the cell, it swells and bursts;
c) ionic composition of the liquid - the kidneys retain or remove certain salts from the blood, depending on their deficiency or excess in the body;
d) acid-base balance - the kidneys maintain a neutral blood reaction, depending on the circumstances, retaining or removing from the body ions of carbonic acid, chlorine, hydrogen and ammonium, the presence of which determines the pH level of the blood. Ammonium ions are formed from ammonia, which is synthesized in the cells of the kidneys themselves;
d) blood pressure– Removing fluid from the body lowers blood pressure.

3. Secretory

Hormones are formed - biological regulators (the enzyme renin, synthesized by the kidneys, activates a regulator that controls blood pressure).

Structure of the urinary system

Task for group No. 1

1. Write captions for the figure. 1.
2. Fill out and analyze the table. 2.

Tasks for group No. 2

1. Write captions for the figure. 2.
2. Tell where the kidneys are located, how many there are, what shape they have, and their weight. (Working with the table “Organs of excretion.”)
3. Characterize the features of the blood supply to the kidneys. (Work with the film strip “Structure and function of the kidneys.”)

Group assignment No. 3

1. Write captions for the figure. 3.
2. Talk about the internal macroscopic structure of the kidney (a dummy is used).

Group assignment No. 4

Using the textbook* (§ 41, pp. 129–130), fill out and comment on the table. 3.

Group assignment No. 5

Using the textbook* (§ 41, pp. 129–130), describe the process of urination.

The results of work in groups are presented in the form of a supporting summary in notebooks and on the board.

Internal (microscopic) structure of the kidney - the structure of the nephron

Teacher's story. The main provisions are entered into the supporting outline.

The kidney has a very complex microscopic structure. The structural unit of the kidney is the nephron - the renal corpuscle (Fig. 4). The nephron has microscopic dimensions. Each kidney has about 1 million nephrons.

The renal corpuscle begins in the cortex of the kidney as a small capsule shaped like a double-walled cup, formed from two layers of epithelial cells. Between these layers there is a slit-like space - the capsule cavity. From it begins the renal convoluted tubule of the 1st order, formed by one layer of epithelial cells. The tubule descends into the medulla of the kidney, where it forms a loop of Henle, then returns to the cortex, receiving the name 2nd order tubule. Here it twists again, merges with the same adjacent tubule and forms the collecting duct of the nephron, passing inside the pyramids.

The collecting ducts merge to form larger excretory ducts. They pass through the medulla to the tips of the papillae of the pyramids. The total length of the tubules of one nephron is 35–50 mm, and the total length of the tubules of the entire kidney reaches 120 km.

Each individual tubule secretes its own small portion of the daily amount of urine.

Inside the renal capsule there is a capillary glomerulus formed from the branches of the renal artery arising from the aorta. It is called the afferent arteriole.

The capillary glomerulus adheres tightly to the nephron capsule, and blood plasma substances easily diffuse from the vessel into the capsule cavity.

The capillaries collect into the efferent arteriole. It again breaks up into capillaries that intertwine the convoluted tubules and the loop of Henle. After this, the capillaries form veins that flow into the inferior vena cava, through which the blood, cleared of toxins, returns to the bloodstream. Reabsorption products also returned here. And urine enters the renal pelvis.

Urine formation

Teacher's story.

The process of producing urine and removing it from the body is called diuresis.

This is very difficult process, it is closely related to the blood supply to the kidneys, which is many times greater than the blood supply to other organs. This ensures the purification of the blood from substances continuously entering it from the cells that must be removed from the body with urine.

Diuresis occurs in two stages (phases).

1. Filtration - substances carried by the blood into the capillaries of the glomerulus are filtered into the cavity of the nephron capsule. This occurs due to a significant difference in pressure in the glomerulus (70 mm Hg) and in the capsule cavity (30 mm Hg).

This high pressure in capillaries is provided:

– slow blood flow;
– pressure difference in the afferent and efferent arterioles;
– high blood pressure in the afferent arteriole (the renal artery arises from the aorta, where the blood is under the highest pressure).

The filtered liquid is called primary urine. In composition, it corresponds to blood plasma without proteins (Table 3).

Primary urine contains many substances needed by the body (sugar, amino acids, vitamins, hormones) and if they are removed from the body, the excretion process will become very wasteful. But this does not happen, since the substances are reabsorbed into the blood in the next phase.

2. Reabsorption - occurs when primary urine moves through convoluted tubules, which are tightly intertwined with capillaries.

Reabsorption occurs:

a) passively - according to the principle of diffusion and osmosis;
b) actively - due to the activity of the epithelium of the renal tubules with the participation of enzyme systems with energy consumption.

During reabsorption, primary urine gives water, glucose, amino acids, vitamins, and a significant amount of potassium and sodium ions to the blood - this ensures the constancy of the internal environment (the second function of the kidneys).

Substances such as urea, ammonia, sulfates, other waste products, as well as excess, for example, glucose are not reabsorbed, their concentration in the urine along the tubules increases, and secondary urine is formed, which must be removed from the body (the first function of the kidneys).

In addition to reabsorption in the tubules, harmful substances that enter the body and the bloodstream from the external environment (dyes, antibiotics, sulfonamides, etc.) are released into their lumen. If these substances are not filtered into capsules, then they are removed from the blood through the capillary network that encircles the convoluted tubule.

Yellow urine depends on the pigment urochrome - a product of the breakdown of hemoglobin.

Regulation of the urinary system

Teacher's story.

The process of urine formation by the kidneys is regulated by the nervous and humoral systems. A person can control the process of urination, and a conditioned reflex can be developed.

Voiding reflex arc: bladder receptors ® neuron sensory pathway ® micturition center in the spinal cord ® diencephalon ® cerebral cortex ® neuron motor pathway ® bladder sphincter muscles.

When the concentration of salts in the blood changes, the receptors of the blood vessels are irritated. If the body lacks moisture or has eaten a lot of salty food, the concentration of salts in the blood increases and a hormone is released in the pituitary gland vasopressin. It enhances the reabsorption of water in the tubules - the fluid returns to the bloodstream and the volume of urine decreases, while the amount of salt excreted remains at the same level. And, conversely, if the concentration of salts in the blood decreases, then hormones are released that reduce the reabsorption of water and promote its removal from the body.

Lesson conclusions

1. The kidney is a complex biological filter.

2. The structure and function of the kidneys allows you to cleanse the blood, removing unnecessary substances from the body, and maintain the constancy of the internal environment of the body.

Application

1 – adrenal gland;
2 – kidney;
3 – ureter;
4 – bladder;
5 – urethra

Rice. 2. External structure kidneys: 1 – “gate” of the kidney;
2 – renal artery; 3 – renal vein; 4 – ureter

Rice. 3. Internal (macroscopic) structure of the kidney:
1 – cortical layer; 2 – medulla, consisting of renal pyramids; 3 – papillae; 4 – pelvis; 5 – ureter

Rice. 4. Structure of the nephron: 1 - nephron capsule; 2 - capsule cavity; 3 - convoluted tubule epithelium of the 1st order; 4 - loop of Henle; 5 - convoluted tubule of the 2nd order; 6 - collecting duct; 7 - glomerulus of capillaries; 8 - afferent arteriole; 9 - blood filtration; 10 - efferent arteriole; 11 - blood flow to the inferior vena cava; 12 - reabsorption; 13 - urine flow; 14 - renal pelvis

* Biology. Human. Textbook for the 9th grade of general education institutions. Edited by A.S. Batueva. – M.: Enlightenment.

The urinary system consists of several interconnected organs. The disruption of one of them “hurts” the others. In medicine, it is customary to isolate these structures into the urinary system. The name change emphasizes the role in the regulation and removal of waste substances, excess carbohydrates, nitrogen-containing products, and electrolytes.

Let us recall that in humans a similar function is also performed:

• intestines;
• leather;
• lungs.

The urinary organs include:

• kidneys;
• bladder;
• ureters;
• urethral canal.

Let's consider the structure of each organ separately, their importance in the process of urine excretion, connections and functioning in a healthy body.

Kidneys and their role

The kidney is a paired organ. Two bean-shaped formations are located on both sides of the spine at the level of the upper lumbar and lower thoracic segments. The fascia sheets are attached to the peritoneum. The kidney is covered with a dense fibrous capsule, then a layer of fatty tissue. On the inside, in the area of ​​indentation, there is a “gate”. Vessels enter and exit them (renal artery and vein), and the beginning of the ureters is located here.

The organ receives oxygen through the renal artery from the abdominal aorta. And venous blood is sent to the portal system.

The peculiarity of the blood supply makes the kidney very vulnerable to the development of atherosclerotic changes in the overlying arteries. Kidney ischemia leads to oxygen starvation of cells and disrupts their function. Proximity to the portal vein creates a dependence on liver function. In diseases leading to cirrhosis with hypertension in the hepatic veins, the renal blood flow also suffers.

The urine-collecting parts include the calyxes (2 rows), which pass into the pelvis (it is the one that connects the kidney to the ureters)

Under the fibrous capsule there are 2 layers:

• cortical;
• cerebral.

They are clearly visible in the section. Wedged into the medulla, the cortex divides it into “pyramids”. The narrow part of the formations is directed inward and ends with holes through which urine collects in the cups. Basic structural unit the kidney is a nephron. In total there are about a million of them already at the birth of a child. The maximum number lies in the cortical layer, less in the medulla.

The structure of the nephron is presented:

• capillary glomeruli from afferent arterioles;
• a capsule of two leaves (Shumlyansky-Bowman);
• system of excretory tubules.

The glomerular epithelium (cubic and cylindrical) together with the vessels forms the basement membrane, through which primary urine is filtered.

The excretory function is carried out by tubular epithelial cells. In addition, they are also able to regulate the acidic and alkaline chemical composition of urine. The connection of the tubules with the excretory openings of the papillae is carried out through collecting ducts.

The renal pelvis is impermeable to urine and is covered from the inside with a membrane of double-layer epithelium. It's called transitional. It is important that the shape of the cells can change and depends on the degree of filling of the pelvis. The wall has muscle fibers from smooth and transverse bundles.

The structure allows you to provide:

• reliable isolation of collected urine;
• peristaltic movements to push fluid into the ureters.

The kidneys perform the following functions:

• produce urine from blood plasma;
• by removing more or less water from the blood into the urine, the body’s water balance is regulated;
• can reduce or increase the water filling of both intracellular and extracellular space in tissues;
• determine, based on the incoming plasma composition, the feasibility of concentrating certain substances for the functioning of organs and systems and remove the excess;
• participate in general metabolism by regulating the excretion of glucose and nitrogenous substances;
• eliminate foreign antibodies from the body if they pass through membrane pores in size;
• are able to retain or pass electrolytes (sodium, potassium), alkaline and acidic substances, thereby regulating the acid-base balance of the blood and ensuring the normal course of biochemical reactions.

Urine is the end result of kidney function

The kidneys synthesize a number of substances necessary for the body:

• the formation of renin, a precursor of angiotensin II, from which the hormone aldosterone is synthesized, leads to vasoconstriction and increased blood pressure;
• erythropoietin - stimulates the production of red blood cells in the bone marrow, damage to this function leads to anemia (anemia);
• kinins and prostaglandins are necessary protein components of any protective anti-inflammatory reaction, coagulation processes;
• by activating vitamin D 3, they participate in phosphorus-calcium metabolism and strengthen bone tissue.

Ureters: structure and functional purpose

The ureters are represented by a pair of muscular tubes connecting the renal pelvis to the bladder. The size of an adult depends on height. Usually the length is between 28-34 cm. In women, the length is 2.5 cm shorter than in men.

According to the anatomical relationship to other organs, it is customary to distinguish 3 sections:

1. Abdominal - located retroperitoneally in the fatty tissue, in front it descends along the lateral surface and is adjacent to the muscles of the lumbar region.
2. Pelvic - in women it passes behind the ovaries, bends around the cervix from the side, lies in the groove between the wall of the vagina and the bladder. In men it goes anteriorly, behind it is the vas deferens. The entrance to the bladder is located at the upper edge of the seminal vesicle.
3. Distal section - located inside the wall of the bladder (intramural part).

Clinicians divide the ureter into three equal parts:

• top;
• average;
• bottom.

The ureter is stretched due to longitudinal folds

The histological structure reveals 3 layers in the wall of the ureteric tube:

• internal - represented by epithelium that produces mucus;
• muscular (medium) – contains fibers of muscle tissue;
• external (adventitial) – covered with a protective connective tissue membrane.

There are anatomical narrowings located:

• at the outlet of the pelvis;
• when crossing the border of the abdominal and pelvic sections;
• in the lower part near the wall of the bladder.

Structure and role of the bladder

The anatomical and physiological conditions of the bladder activity should ensure:

• intake of urine from the ureters;
• accumulation and storage;
• pushing into the urethra.

For men, a spherical shape is more typical; for women, an oval shape is more typical.

Located in the pelvis. It is a muscle sac. When overfilled, the upper part rises to the abdominal cavity.

The wall has three layers. Internal (epithelial) - formed by transitional epithelium, between the cells of which there are goblet-shaped formations that produce mucus. Thanks to this substance, irritating factors and bacteria are removed (washed away) from the bladder.

Muscular - consists of three layers of fibers connected to form a detrusor (expulsion muscle). The storage function is supported by two sphincters of compacted muscles in the neck of the bladder. Ring-shaped formations provide communication with the urethra and are abundantly supplied with nerve endings.

The fiber structure in them is:

• from the inner layer - represented by smooth muscle tissue;
• outer - has a cross-striped pattern.

Another 2 sphincters are located at the inlet openings on the border with the ureters. Anatomically, the zone is identified between the two ureteric inlets and the cervical sphincter. It is called a triangle and is lined with columnar epithelium. Its peculiarity is the lack of ability to stretch.

The urethra is the final part of the urinary system

The urethral canal communicates between the bladder and external environment. Its main task:

• removal of accumulated liquid to the outside;
• ensuring retention of a small volume (up to 15 ml) using your own muscles and three sphincters.

The structure has gender differences. In women, the urethra:

• significantly shorter (3-5 cm versus 15-18 cm in men);
• in diameter, elongation in women reaches 15 mm;
• passes in front of the vagina, the external opening is close to the anus.

In men, there are 3 sections of the urethral canal:

• prostatic – length 3-3.5 cm, passes through the prostate gland, close to the seminal tubercle and excretory ducts (seminal fluid enters the urine);
• membranous - only 2 cm below the prostate, narrowed part;
• spongy - length about 12 cm, runs along the spongy bodies.

The boys in childhood the prostatic part is relatively longer than the others.

Consists of three layers:

• mucous;
• submucosal;
• muscular.

The role of pelvic floor muscle training is taken into account in the treatment of urinary incontinence

It is important that in the initial part of the urethra the sphincter has the ability to contract and relax on its own, and in the pelvic floor muscles there is a sphincter that can be controlled by a person.

The mechanism of the urinary organs

The work of the urinary system includes sections:

• formation of urine in the kidneys;
• excretion from the pelvis through the ureters into the bladder;
• accumulation and preservation to a critical volume inside the bubble;
• ensuring urination through the urethral canal.

Urine formation

In the glomeruli of nephrons, primary urine is formed by filtration, which accumulates in the Shumlyansky-Bowman capsule. It contains:

• urea;
• glucose;
• phosphates;
• sodium salts;
• creatinine;
• uric acid and its compounds;
• vitamins.

Further, passing through the tubules, the composition of urine changes significantly: some of the substances and up to 80% of the water are reabsorbed (reabsorption). Glucose, sodium ions, chlorides, part of the urea, and vitamins are retained.

The final “refinement” of the contents occurs in the tubules, where unnecessary salt or alkaline components are removed. Secondary urine with the final level of concentration of waste substances enters the cups.

An important feature of the child’s body is the imperfection of filtration until the age of 3-6 years. Due to the short size of the tubules, children's kidneys cannot excrete a large number of water from the body. And weak reabsorption in epithelial cells causes a tendency to shift the acid-base balance towards acidosis.

The following are involved in the control of urine excretion and formation:

• angiotensin II - narrowing the arteries, reduces renal blood flow, and therefore filtration, increases the reabsorption of sodium ions in the tubules;
• an area of ​​the medulla oblongata called the hypothalamus - synthesizes antidiuretic hormone, which accumulates in the posterior lobe of the pituitary gland, when released into the blood, enters the kidney tissue, activates the reabsorption of water;
• the adrenal glands produce aldosterone - its effect is to retain sodium and remove potassium, along with sodium ions, the release of water is suspended;
• sympathetic impulses from nerve fibers cause vasoconstriction of the kidneys, reducing filtration;
• parasympathetic nerves - increase blood flow and, accordingly, the rate of urine output.

Mechanism of urination

Transportation of urine from the pelvis through the ureter occurs due to the ability of muscles to alternately contract. Filling of each segment of the tube causes a simultaneous blockage in the overlying sections so that the flow of urine cannot return to the pelvis.

Normally, a person is able to consciously hold urine

Urine accumulation

The accumulation and storage of urine is ensured by the dense structure of the bladder and its sphincters, and the ability to mostly stretch. The maximum volume of accumulated liquid reaches from 400 to 700 ml.

The process of urination

Urination depends on the condition of the urethral canal and its sphincters. The urge occurs if 300-400 ml of liquid accumulates in the bladder. Usually this much accumulates during normal drinking regime in a person in 3-3.5 hours.

The process of removing urine from the bladder is strictly controlled by the central and autonomic nervous systems; there are centers in the brain responsible for the correct release of urine. In addition, the nerve fibers of the spinal cord at the level of the lumbosacral region play a major role. They are directed to the detrusor of the bladder, its sphincters.

The constrictions of the urethral canal are innervated by the pudendal nerve, which receives signals from the Onuf nucleus of the brain. Children begin to control urination by age three.

As the bladder fills, its epithelial cells stretch and flatten. Nerve receptors respond to this process. The reflex relationship between urine storage, retention and the voiding phase is regulated by the sensitivity of these nerve endings. A person is able to consciously control the process.

From the stretched wall, signals travel along the pelvic nerves to the centers of the spinal cord. Reverse instructions prepare all sphincters and detrusor to expel urine.
After emptying, the bladder wall relaxes and it begins to accept further portions of urine from the kidneys. During storage, the internal sphincter of the bladder remains tense.

High fluid pressure in the bladder and relaxation of the external urethral sphincter create the necessary conditions for the release of a stream of urine. Usually several similar contractions occur.

The urinary system does not work in isolation. It is even anatomically adjacent to neighboring organs:

• liver;
• intestines;
• pancreas;
• genital structures.

U healthy person the general vital activity of the body is ensured by all organs and systems. The failure of one of the components causes a sensitive blow to the others. Therefore, kidney pathology is accompanied by various concomitant lesions.

1. The meaning and structure of the urinary system.

The significance of the excretion of waste products of the body. In the process of metabolism, end products are formed in cells. Among them there may be substances that are toxic to cells. So, when breaking down amino acids, nucleic acids and other nitrogen-containing compounds, toxic substances are formed - ammonia, urea and uric acid, which, as they accumulate, must be eliminated from the body. In addition, excess water, carbon dioxide, poisons that come with inhaled air, absorbed food and water, excess vitamins, hormones, medications, etc. must be removed. With the accumulation of these substances in the body, there is a danger of violating the constancy of the composition and the volume of the internal environment of the body, which can affect human health.

Excretory organs and their functions. The excretory function is performed by many organs. Thus, the lungs remove carbon dioxide, water vapor, and some volatile substances from the body, for example, ether vapor, chloroform during anesthesia, and alcohol vapor during intoxication. The sweat glands remove water and salts, small amounts of urea, uric acid, and during intense muscular work, lactic acid. The salivary and gastric glands secrete some heavy metals, a number of medicinal substances, and foreign organic compounds. The liver performs an important excretory function, removing hormones (thyroxine, folliculin), products of the breakdown of hemoglobin, nitrogen metabolism and many other substances from the blood. The pancreas and intestinal glands remove salts of heavy metals and medicinal substances. However, the main role in the excretion processes belongs to specialized organs - the kidneys. The most important functions of the kidneys include participation in the regulation of: 1) the volume of blood and other internal fluids, 2) the constancy of the osmotic pressure of blood and other body fluids, 3) the ionic composition of internal fluids and the ionic balance of the body, 4) acid-base balance, 5 ) removal of end products of nitrogen metabolism and foreign substances from the body. Thus, the kidneys are an organ that ensures homeostasis of the internal environment of the body.

Structure of the urinary system The organs included in the urinary system are responsible for filtering the blood and removing waste fluid from the body. The urinary system consists of the following structures: two kidneys, which are located on the posterior wall of the abdominal cavity directly above the lower back on either side of the spine; two ureters that connect the kidneys to the bladder; the bladder and the urethra (urethra), which connects the bladder to the external environment.

How the urinary system works The outer part of the kidneys (cortex) contains thin tubes that filter waste substances from the blood. The filtered liquid enters the central part of the kidneys - the medulla, where the reabsorption of some substances from it occurs. The resulting fluid (urine) is directed through the ureters to the bladder, which is kept closed thanks to a ring of muscles (sphincter). The accumulated urine periodically leaves the bladder through the urethra.

Rice. 1. Structure of the urinary system: 1 - kidney; 2 - kidney gate; 3 - ureter; 4 - bladder; 5 - urethra; 6 - adrenal glands.

Functions of water-electrolyte metabolism: water in the body plays a transport role, filling cells, interstitial (intermediate) and vascular spaces, is a solvent of salts, colloids and crystalloids and takes part in biochemical reactions. All biochemical liquids are electrolytes, since salts and colloids dissolved in water are in a dissociated state. It is impossible to list all the functions of electrolytes, but the main ones are: maintaining osmotic pressure, maintaining the reaction of the internal environment, participating in biochemical reactions. The main purpose of acid-base balance is to maintain a constant pH of body fluids as the basis for normal biochemical reactions and, therefore, life activity. Metabolism occurs with the indispensable participation of enzymatic systems, the activity of which closely depends on the chemical reaction of the electrolyte. Together with water-electrolyte metabolism, acid-base balance plays a decisive role in the ordering of biochemical reactions. Buffer systems and many physiological systems of the body take part in the regulation of acid-base balance.

Regulation of blood osmotic pressure and extracellular water volume. Blood osmotic pressure is an important indicator of homeostasis. Osmoreceptors that respond to its changes are located in the nuclei of the hypothalamus, in the liver, heart, kidneys and other organs. Water reabsorption increases under the action of the antidiuretic hormone - ADH (vasopressin), which is released from the pituitary gland in response to a decrease in blood osmotic pressure. The content of vasopressin in the blood depends on the circadian rhythm, i.e. During the day, a person produces less of it than at night. In case of disturbances in the regulation of ADH formation, nocturia may be observed - nocturnal discharge large quantities urine. The formation of ADH increases significantly during painful stimulation; in response to a painful stimulus, painful anuria occurs, i.e. cessation of urine output. When vasopressin secretion is suppressed, diuresis increases sharply (more than 10-20 final urine output), and polyuria develops. With a decrease in the level of sodium ions in the blood, the production of the hormones aldosterone increases, which increases the activity of the sodium-potassium pump in the renal tubules and helps to increase the reabsorption of sodium from primary urine. When too high level sodium ions in the blood increases the production of natriuretic hormone in the hypothalamus and atria, which, on the contrary, reduces the reabsorption of sodium in the renal tubules and increases its excretion in the urine.

Hematopoiesis (hematopoiesis), the process of formation, development and maturation of blood cells - leukocytes, erythrocytes, platelets. Hematopoiesis is carried out by hematopoietic organs. Embryonic (intrauterine) hematopoiesis is distinguished, which begins in very early stages embryonic development and leads to the formation of blood as tissue, and postembryonic hematopoiesis, which can be considered as a process of physiological renewal of blood. In the adult body there is a continuous process mass death formed elements of blood, but dead cells are replaced by new ones, so that the total number of blood cells is maintained with great constancy.

The structure of reticular (hematopoietic) tissue. In the red bone marrow there are so-called stem cells - the precursors of all the formed elements of blood, which (normally) come from the bone marrow into the bloodstream already fully mature. No more than 20% of stem cells simultaneously take part in the process of hematopoiesis, while most of them are at rest. Hematopoietic stem cells are capable of differentiating into Various types blood cells. The differentiation process takes place in several stages. Thus, the process of erythropoiesis (formation of red blood cells) includes the following stages: proerythroblasts, erythroblasts, reticulocytes and, finally, red blood cells. The duration of erythropoiesis is 2 weeks.

Granulocytes are also formed in the bone marrow, with neutrophils, basophils and monocytes coming from one (pluripotent) cell - the precursor of neutrophils and basophils, and eosinophils - from another (unipotent) cell - the precursor of eosinophils. As granulocytes differentiate, cell sizes decrease, the shape of the nucleus changes, and granules accumulate in the cytoplasm. The process of development of granulocytes is morphologically distinguished into 6 stages: myeloblast, promyelocyte, myelocyte, metamyelocyte, band and segmented granulocytes. Granules specific to each type of granulocyte appear at the myelocyte stage. Cell division stops at the metamyelocyte stage.

Platelets give rise to the largest (30-100 microns) cells of the bone marrow - megakaryocytes, which have a lobed nucleus with a polyploid set of chromosomes.

Lymphocytes, unlike other blood cells, can form both in the bone marrow (B-lymphocytes) and in the tissues of the immune system: the thymus gland (thymus) (T-lymphocytes), in the lymph nodes, and in other lymphoid organs. A mature lymphocyte is much smaller than its predecessor cell, the lymphoblast, but many lymphocytes can, when stimulated by antigen, enlarge and again acquire the morphology of a lymphoblast.

Thus, the bone marrow plays a central role in the immune system, since it produces B lymphocytes and also contains a large number of plasma cells that synthesize antibodies. In addition to hematopoiesis, the bone marrow, like the spleen and liver, removes old and defective blood cells from the bloodstream.

2.Structure of the urinary organs.

External structure of the kidneys

Rice. 2. Kidneys and ureters.

right kidney

left kidney

adrenal glands

abdominal aorta

inferior vena cava

renal artery

renal vein

ureter

ureter

The kidneys are excretory organs located behind the peritoneum in the lumbar region on the posterior wall of the abdominal cavity at the level from the XII thoracic to the I, II lumbar vertebrae on the sides of the spine. The right kidney lies 1.5 cm below the left. The kidney has a bean-shaped shape. Its surface is smooth and dark red in color. The kidney has two poles - upper and lower, two edges - internal concave and external convex, two surfaces - anterior and posterior. At the inner edge of the kidney is the renal hilum, through which the renal artery, renal vein, lymphatic vessels, nerves and ureter pass. The mass of each kidney of an adult is about 150 g, length - about 10 cm. The kidney is surrounded by its own dense connective tissue membrane in the form of a thin smooth film directly adjacent to the substance of the kidney. This shell can be easily separated. On top of this membrane is a layer of loose adipose tissue, which forms the fatty capsule of the kidney. The fat capsule helps cushion, protect and more firmly fix the kidney in a certain position. The importance of this function of the fat capsule is evident from the following: during prolonged fasting, fat acts as a reserve nutrient, from the fatty capsule of the kidneys is the last to be consumed. Prolapse of the kidneys is a pathology that occurs due to a violation of their correct position, leading to difficulty in the blood supply to the kidneys and disruption of their function. Adjacent to the upper pole of each kidney is an endocrine gland - the adrenal gland.

Internal macroscopic structure of the kidneys

Rice. 3. Internal structure of the kidney (longitudinal section).

1 - large calyx; 2 - small cups; 3 - renal pelvis; 4 - ureter; 5 - medulla (renal pyramids); 6 - papillae of the pyramids; 7 - cortex.

A longitudinal section through the kidney shows that the kidney consists of a cavity and the renal substance itself. The renal substance consists of two layers: the cortex and the medulla. The cortex occupies a peripheral position and has a thickness of about 4 mm. The medulla occupies an internal position and consists of conical formations called renal pyramids. The bases of the pyramid face the periphery of the kidney, and the apexes face the cavity of the kidney. The cortex extends into the medulla, forming renal columns that separate the pyramids. The renal cavity is occupied by the small and large calyces and the renal pelvis. There are 8 - 9 small calyces. Each small calyx covers the top of the pyramid. Combining several at a time, they form large cups (usually there are two of them - upper and lower). The large calyces merge into one renal pelvis, which partially protrudes from the hilum of the kidney.

Microscopic structure of the kidneys The kidney is a complex tubular gland. The structural and functional unit of the kidney is the nephron. The nephron looks like a thin tube with a microscopic diameter, about 30 - 50 mm long. Each kidney has about a million nephrons. The nephron begins with an enlarged region called the nephron capsule, or Shumlyansky-Bowman capsule. The capsule is a double-walled cup or glass. The walls of the capsule are formed by single-layer epithelium, and its inner layer is squamous epithelium. The capsule tightly covers the capillary glomerulus. This glomerulus begins with the afferent arteriole and ends with the efferent arteriole. The diameter of the afferent arteriole is larger than that of the efferent arteriole, so increased pressure is created in the capillary glomerulus. The capillary glomerulus, together with the capsule enclosing it, forms the renal (Malpighian) corpuscle. Renal corpuscles lie in the cortex of the kidneys and are visible to the naked eye in the form of small red dots. From the capsule of the renal corpuscle begins a convoluted tubule of the first order (proximal tubule), which continues into the loop of Henle. The loop is followed by a convoluted tubule of the second order (distal tubule), which passes into the intercalary region. The loop of Henle lies in the medulla of the kidney. The walls of the nephron are formed by single-layer epithelium, the shape of the cells of which is different in its different parts (for example, the wall of the first-order convoluted tubule is formed by ciliated epithelium).

Blood vessels of the kidneys

Blood enters the kidney through the renal artery, which arises from the abdominal aorta. About 25% of the blood pushed out by the left ventricle enters the kidneys, which is approximately 1.5 thousand liters per day. The renal artery in the kidneys breaks up into a system of small arteries up to the level of the afferent arterioles of the renal corpuscles, which give rise to the capillary glomerulus. The efferent arteriole of each renal corpuscle breaks up into a system of capillaries that form a network around the nephron. From this network, venules and veins are formed, eventually merging into the renal vein. Thus, there are two capillary systems in the kidneys:

capillaries of the renal corpuscles, in which there is no change of blood from arterial to venous

capillaries covering the nephron tubules, in which the blood changes from arterial to venous.

The first network ensures blood filtration, the second - metabolic processes in the kidneys.

Rice. 4. Scheme of the structure of the nephron (A), Malpighian corpuscle (B) and the epithelium of various parts of the nephron tubule (C).

A: 1 - Malpighian body; 2 - convoluted tubule of the first order (proximal); 3 - descending loop of Henle; 4 - ascending loop of Henle; 5 - convoluted tubule of the second order (distal); 6 - intercalary section of the nephron; 7 - common collecting duct.

B: 1,2 - outer and inner walls of the Shumlyansky-Bowman capsule; 3 - cavity inside the capsule; 4 - afferent arteriole; 5 - capillary glomerulus; 6 - efferent arteriole; 7 - cuboidal epithelium of the proximal tubule; 8 - microcilia of epithelial cells; 9 - squamous epithelium of the loop of Henle; 10 - epithelium of the distal tubule.

The work of cells leads to the formation of harmful substances that the body needs to remove. This problem is solved by absorbing some substances for reuse and removing others. Removal harmful products carried out in four ways: during breathing, with sweat, with feces and with the help of the urinary system. The latter is the excretory system itself, 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.

Removing harmful substances from the body

Organs of the urinary system

The kidneys filter the blood and form urine from water and harmful substances, which is removed from the body through the urinary system.

The ureters are channels connecting the kidneys to the bladder.

The urethra is the channel through which urine accumulated in the bladder is removed from the body. These organs are different for men and women.

The bladder is an elastic muscular organ in which urine coming from the kidneys accumulates.

3.Urine formation.

The kidneys produce urine from the plasma of the blood flowing to them. The process of urine formation is divided into two stages: the formation of primary urine and the formation of secondary urine. Blood plasma under high pressure is filtered through the walls of the capillaries into the renal capsule. The walls of the capillaries and the kidney capsule do not allow blood cells and large protein molecules to pass through, but they do allow some substances dissolved in the blood plasma to pass through. Primary urine is a liquid formed in the cavity of the renal capsule. From the renal capsule, primary urine enters the renal tubule, the thin walls of which absorb water from it and some dissolved substances needed by the body, and release harmful substances into it. Substances necessary for the body are returned to the blood through a network of capillaries intertwining the renal tubule, and the products of the final breakdown of substances or unnecessary compounds form secondary urine. The resulting urine flows into the renal pelvis, and from it periodically enters the bladder through the ureters. Absorption of water continues in the bladder. into the blood. When the bladder is filled to a certain limit, irritation of the receptors in the bladder wall occurs, which causes a reflex contraction of its muscles and relaxation of muscle thickenings, leading to emptying of the bladder, i.e., urination. The micturition response center is located in the spinal cord and is under the control of the brain.

Urinary organs:

renal cortex

medulla

renal calyces

pelvis

ureter

bladder

urethra

Nervous and humoral regulation of kidney activity

The human body is a system of highly differentiated cells, tissues, and organs, the coordinated work of which is an indispensable condition for the normal functioning of the body. On the other hand, for the normal functioning of the body, a state of homeostasis is necessary, i.e. maintaining consistency chemical composition And physical and chemical properties cells, tissues and internal environment of the human body. Finally, the human body exists in conditions of constant changes in the internal and external environment, to which it is necessary to constantly adapt. Integration (coordination) of processes and functions of the body and adequate adaptive reactions of the body are carried out thanks to the continuous flow of regulatory processes. In the human body there are two main types of regulation of functions: nervous and humoral regulation. The first is carried out as a result of activities nervous system, the second - due to the activity of the endocrine glands and other organs with secretory activity. Physiological processes in all cells, tissues, and organs are under continuous regulatory influence from the nervous and endocrine systems. Thanks to this, the state of homeostasis of the body and the body’s adaptation to the specific state of the internal and external environment are most subtly and accurately maintained.

Both types of regulation have their own characteristics:

Nervous regulation

Humoral regulation

Communication with the organs to which the regulatory influence is directed is carried out along nerve pathways.

The regulatory effect is carried out through the distribution of biologically active substances by body fluids

There is an exact “addressee” (organ, tissue, group of cells) to which the regulatory effect is directed.

There is no precise direction, so a large number of organs are involved in the response.

Very high speed of regulatory influence, because the speed of nerve impulse reaches 120 - 140 m/s

The speed of regulatory influence is hundreds of times lower than nervous regulation

Rapid cessation of regulatory influence possible

The cessation of regulatory influence is extended over time

Both types of regulation, having their own characteristics, complement each other and are interconnected, therefore it is more correct to talk about a single regulatory mechanism - neurohumoral regulation, thanks to which the body exists as a single whole. The main centers of coordination and coordination of the nervous and endocrine regulatory systems are the hypothalamus (sub-thalamic part of the diencephalon) and the pituitary gland. The hypothalamus and pituitary gland together form the hypothalamic-pituitary system. The hypothalamus produces neurohormones that enter the pituitary gland and regulate its activity. Neurohormones liberins increase, and statins slow down the production of pituitary hormones.

4. Age-related features of the kidney structure.

The intensity of kidney growth is not the same at different age periods. The most intensive growth occurs in the first 3 years of life, during puberty and at 20-30 years of age. The kidneys of newborns have a lobular structure, which is somewhat smoothed out by one year due to the growth in width and length of the urinary tubules. An increase in the volume and number of these tubules helps smooth the boundaries between the kidney lobules. At the age of 5, the lobulation of the kidneys disappears in most children. However, in rare cases, lobulation persists throughout life. The ratio of the cortical and medulla layers of the kidney changes quite dramatically with age. While in an adult the thickness of the cortical layer is 8 mm, and the medulla is 16 mm, in a newborn it is, respectively, 2 mm and 8 mm. Consequently, the ratio of the thickness of the cortical and medulla layers in adults is 1: 2, and in children - 1: 4. The growth of the renal cortical layer occurs especially intensively in the first year of life, when its thickness doubles. In the cortex of the kidneys of newborns there are many small Malpighian corpuscles, quite tightly adjacent to each other. There are 50 glomeruli per unit volume of an almost newborn (in adults - 4-6, and in 8-10-month-old children - 18-20). With age, the urinary tubules, growing in size, increasingly increase the distances between neighboring bodies and at the same time move them away from the kidney capsule. The latter leads at the age of 1-2 years to the formation of a glomerular-free layer under the kidney capsule, the width of which increases up to 14 years. In the first 20 days of a child’s life, the formation of new Malpighian bodies is possible. At the same time, throughout the first year, the kidneys of children contain nephrons that have undergone reverse development (sclerosed). With age, their number steadily decreases. From 7 to 50 years of age, reverse development of nephrons is observed quite rarely. Thus, not all nephrons that are formed in the embryonic period develop to full maturity: some of them undergo reverse development and die. The reason for this phenomenon is that nerve fibers grow into the kidney after the formation of nephrons, and the nerve branches do not reach some of them. These nephrons, deprived of innervation, undergo reverse development, being replaced by connective tissue, i.e. sclerosing. The nephrons of the kidneys of newborn children are immature, which is expressed in the peculiarities of the cellular structure of the capsule. The epithelial cells of the inner layer of the capsule are very tall (columnar and cuboidal epithelium). The leaf itself covers the vascular glomerulus only from the outside, without penetrating between the individual vascular loops. With age, the height of the cells decreases: the cylindrical epithelium turns first into cubic and then into flat. Moreover, the inner leaf of the capsule begins to penetrate between the vascular loops, evenly covering them. The diameter of the glomerulus in newborns is very small, so that the total filtration surface per unit mass of the organ is significantly less than in an adult. The urinary tubules in newborns are very narrow and thin. The loop of Henle is short, its apex extends into the cortex. The diameter of the urinary tubules, as well as the renal corpuscles, increases up to 30 years. The cross-section of the convoluted tubules of the kidneys of children is 2 times narrower than that of adults. In newborns, the diameter of the tubule is 18-23 microns, in an adult - 40-60 microns. The renal pelvis in newborns and infants is most often located in the kidney parenchyma itself. The greater the age, the more cases of the pelvis being located outside the renal parenchyma. At 3-5 years, the fatty capsule of the kidney is formed, which ensures a loose connection of the kidneys with the adrenal glands. With age, the vascular network of the kidneys changes. Age-related changes in the arterial system of the kidneys are expressed in thickening of the outer and inner walls of the arteries and a decrease in the thickness of the middle wall. At the same time, smooth muscle cells appear in large numbers both in the inner and outer layers. Only by the age of 14, the thickness of the arterial wall of the vessels of the hummocks turns out to be the same as in adults. In the venous plexus of the kidneys of newborns, it is impossible to distinguish individual trunks. The latter appear only at 6 months of age. At 2-4 years of age, the structure of the kidney veins is the same as in adults. The lymphatic system of the renal pelvis in children is connected with the intestinal lymphatic system more closely than in adults. In this regard, in children, it is possible for intestinal bacteria to spread from the intestines to the renal pelvis, which leads to the occurrence of an inflammatory process in them. In newborn children, they are located slightly higher than in adults. The upper pole of their kidneys corresponds to the lower edge of the 11th thoracic vertebra; Only by 2 years of age is the level of kidney location the same as in adults.

5. Enuresis, its causes and prevention.

Currently, enuresis is understood as involuntary urination during night and daytime sleep in a child with unsteady urinary control that is not appropriate for his age. The term “nocturnal enuresis” is not entirely accurate, because involuntary urination can also occur during daytime sleep. It would be correct to call this disease “sleepy enuresis.” However, it was decided to keep the usual name of the disease. Doctors who use this term put the correct content into it.

Nocturnal enuresis should be distinguished from constant urinary incontinence (day and night) as a consequence of congenital anatomical disorders of the urinary tract. Persistent urinary incontinence is a urological disease that can be cured in most cases after surgical intervention.

At first glance, nocturnal enuresis is a harmless disease that does not deserve special attention. However, changes that are imperceptible at first in a child’s character are often not taken into account - isolation, secrecy, sometimes aggressiveness, etc., which can leave an imprint on the person’s entire subsequent life. It is known how difficult and sometimes impossible it is to “correct” the existing character of an adult. In addition, we must not forget about the inconvenience in everyday life for families where there are children with this disease. The mother has to constantly wash clothes and bedding. The smell of urine can be felt in the room where the child sleeps.

At a very early age, the main factor in urinary incontinence in children is most often a conditioned reflex. A child accustomed to being put on the potty at a certain time subconsciously expects the same during sleep. Accustomed to the presence of his mother, he may wet himself at night if the mother does not respond to his call. This type of enuresis, developing at an early age, can be observed in children up to five years of age.

Another cause of enuresis in children may be uneven psychomotor development, or the so-called dysontogenetic factor. Such children are characterized by a slower level of motor and mental development, they later begin to sit, walk, talk, etc. In some cases, evidence of uneven psychomotor development may be excessive speed of movements or, conversely, their stiffness.

The cause of enuresis can be a simple lack of attention and love from parents. This is the so-called factor of pedagogical neglect. Parents may pay too little attention to the child for various reasons: some are simply not capable of showing feelings for the child, some are too busy at work, and some simply believe that they should not “pamper” the child, especially a boy, pet him too much. Children suffering from a lack of manifestations of parental feelings, as a rule, are either extremely overexcited or, on the contrary, inhibited. In this case, enuresis can be stable and very long-lasting.

Often, childhood enuresis can be caused by so-called minimal brain dysfunction. This disorder is most often observed when the child’s parents suffer from alcoholism. It is alcohol that has a traumatic effect on the child’s brain system, which manifests itself, in particular, in pathological disturbances in the sleep process. Enuresis in this case is a relaxation reflex acquired from parents in the form of an act of involuntary night or daytime (during sleep) urination, which is often observed in alcoholics in a state of intoxication. Children suffering from minimal brain dysfunction have a general decreased level of emotionality. The experiences and feelings of such children are shallow, superficial, and self-criticism is practically absent.

Enuresis resulting from cerebral organic insufficiency (or cerebral organic factor) is another type of bedwetting in children. The most obvious signs in this case are increased motor activity of the child, excitability, frequent mood swings, conflict, pugnacity, inability to live in a group, and an almost complete lack of criticism of one’s own shortcomings. In this case, enuresis is caused by birth trauma, which entails increased and painful excitability of the brain.

A less common cause of enuresis in children may be the so-called neurotic factor. In this case, the child's urinary incontinence is not stable - sometimes for a short or even quite a long period of time he can remain dry in bed. Urinary incontinence is observed against a general background of increased emotional state, feelings of fear or anxiety, when the child is frightened by something or is simply overexcited, that is, in this case, the cause of urinary incontinence should be sought in a stressful situation. Stress is a trigger; if this is short-term stress, then enuresis stops over time and resumes only when the next stress is repeated. If the child lives in constant stress(for example, he is haunted by nightmares, he is afraid of the dark, etc.), then, accordingly, enuresis is more stable and permanent. As a rule, such children are very worried about their deficiency and try their best to hide enuresis from their parents and other family members.

Often, those who suffer from enuresis are those who are not similar in temperament to their parents, especially the mother (or the family member who is raising the child).

If enuresis occurs at any age, you should consult a doctor as soon as possible, because Sometimes simple tips regarding hygienic maintenance can give a good effect. If left untreated, enuresis can continue for a long time, leading to disturbances in the child’s mental sphere. There are currently a number effective methods treatment of enuresis. Treatment is prescribed strictly individually, because remedies that are effective in treating one child may be useless for another.

Psychotherapeutic treatment is carried out both on an outpatient basis and in the hospital. Hypnotic sessions are most often group sessions.

Another method of treating bedwetting is the use of conditioned reflex therapy using the Laskov apparatus. The principle of its operation is that during involuntary urination, the first drop of urine closes an electrical circuit, resulting in electrocutaneous irritation that promotes the awakening of the child, which coincides with the contraction of the external sphincter. Urination stops, the child wakes up and goes to the toilet. After a number of repetitions, a conditioned reflex of awakening at the onset of involuntary urination is developed.

One of the ancient methods of treatment various diseases acupuncture for both children and adults. It is also used for bedwetting. This treatment method is not always effective, and only a doctor can determine the indications for treatment of children with enuresis.

Of the medications in our country and abroad, the most widely used is melipramine, which can only be prescribed by a doctor. The medication is used both in hospital settings and in outpatient practice. Due to the fact that the drug has some side effects, it is important that parents closely monitor the child and immediately notify the attending physician of any observed abnormalities.

A child suffering from bedwetting should engage in hardening, which serves as a means of preventing colds. These diseases can provoke age-related enuresis after successful treatment of the disease, and from practice it is known that cooling an unhardened healthy body often leads to colds.

Enuresis is not only medical, but also pedagogical problem Therefore, in the complex treatment of this disease, a special role should belong to the child’s parents. Children suffering from enuresis may experience changes in behavior and character, which serve as an obstacle to communication with others and make it difficult to stay in a group. The pedagogical work of parents should be aimed at strengthening the child’s desire to recover. It is necessary to create an environment in which external stimuli are excluded during the child’s sleep, as well as worries and worries. Much attention should be paid to normal relationships in the family.

Related information.

The urinary system is an important component of a larger genitourinary system. In men and women, the urinary organs are located close to the reproductive system, so they are often combined. Inflammatory diseases of one system quickly spread to another, and treatment is usually carried out in general for the urinary and genital organs.

The woman's urinary system performs 2 essential functions: removal of excess fluid and elimination of toxins and harmful substances that enter the body along with the fluid. A person consumes 1 to 2.5 liters of liquid per day.

Water is of great importance for the functioning of the body, since all processes and chemical reactions in the human body occur with the participation of water. The same water is necessary for “washing out”, removing harmful substances, which is what the urinary system does.

A woman’s urinary (urinary) system includes several important organs, vessels and arteries, the work of each of which is important for the health of the entire body.

Main components:

• . The kidneys are a paired organ that serves as a kind of filter for the body. Without normal kidney function, toxins accumulate in the body, poisoning occurs, and the functioning of all systems and organs is disrupted. The kidneys are located on the sides of the lumbar vertebrae and resemble beans in appearance. This is the main and most important organ of the urinary system.
• Renal pelvis. This is a small funnel-shaped cavity located on the concave side of the kidney. The pelvis collects urine from the kidney and discharges it into the ureter.
• Ureter. The ureters are 2 hollow tubes that connect the renal pelvis to the bladder. Their length depends on the individual characteristics of the organism.
• Bladder. This organ is located in the lower abdomen and acts as a storage device. It is elastic and stretches well. Excreted urine accumulates in the bladder, which is then excreted from the body.
• The urethra (urethra). A tube-shaped organ that carries urine out. The female urethra is located in a cavity, not visible to the eye, and is also wider and shorter than the male urethra. It is located in front of the vagina and performs only 1 function - excretion of urine.

Features of the female urinary system, differences from the male

The structure of the human urinary system

Unlike the genital organs, the organs of the urinary system in men and women are not fundamentally different. All people have the same presence of kidneys, pelvis, vena cava, etc. The only important difference is the urethra. In men, it performs 2 functions: seminal and urinary. In women, the urethra is solely responsible for the removal of urine.

In men, the urethra is longer, its length reaches 23 cm. The female urethra is much shorter, no more than 5 cm. Due to its short length, the urethra in women is more susceptible to inflammatory diseases. For the same reason, inflammation of the urethra in women more often leads to cystitis.

The bladder in men and women does not have any fundamental differences, but in women it is more oval, in men it is rounded. Because of the uterus, women's bladders are somewhat saddle-shaped.

The functioning of the urinary system is the same in men and women.

The kidneys filter the blood, absorbing all harmful substances. The toxins are then converted into urine, which is excreted into the pelvis, from the pelvis through the ureters into the bladder. To prevent a person from having to urinate every time they filter, the bladder stores urine. When it is full, a person begins a reflexive urge to urinate, and then the urine is discharged through the urethra.

Useful video - Diseases of the urinary system:

The muscles of the bladder play an important role in the process of secretion and elimination of urine. In men and women they have some differences due to the characteristics of the reproductive system. In women, these muscles go to the external opening of the urethra, in men - to the seminal tubercle.There is also a sphincter that prevents urine from being released spontaneously when the bladder is full. It acts as a lock.

The peculiarity of the urinary process is that it is controlled by the human consciousness and, in the absence of diseases, does not occur voluntarily. But this control is not innate; children learn to control their urination during the first 1-2 years of life. Girls often learn faster.

Possible diseases of the female urinary system

Diseases of the urinary system are often associated with the genital organs and sexually transmitted infections, and therefore can lead to impaired fertility. Diseases of the urinary organs in women require special attention and timely treatment.

• . Inflammation of the urethra is one of the most common diseases of the urinary system. In women it occurs quite often, but in men it is more severe. The main symptoms of urethritis: pain and discomfort when urinating, discharge from the urethra and vagina with a strong odor, cloudy urine or urine with a strong unpleasant odor.
• Cystitis. In women, cystitis usually occurs simultaneously with urethritis. Inflammation from the urethra quickly spreads to the bladder. Most often, it is bacteria that enter through the urethra that lead to cystitis. Symptoms of cystitis: pain in the lower abdomen in women, which intensifies when urinating, nausea, fever, difficulty urinating, frequent urge.
• . Pyelonephritis is usually bacterial in nature and is accompanied by inflammation of the renal pelvis. In women, pyelonephritis occurs almost 6 times more often than in men. This disease leads to extreme heat (up to 40 degrees), fever, chills, vomiting and nausea, and pain in the lumbar region.
• Amyloidosis. In this disease, damage to kidney tissue is secondary. The disease is accompanied by metabolic disorders, as a result of which protein settles in the kidney tissues. This is a dangerous disease that leads to disruption of all systems and organs, and can also be fatal.
• . A cyst is a benign hollow formation filled with fluid. Large cysts disrupt blood circulation and urine outflow and can lead to an inflammatory process in the kidney tissues.

It is advisable to treat diseases of the urinary system at the earliest stages, since in an advanced form they lead to serious complications and disorders not only of urinary and sexual function, but also of the functions of all body systems.

Possible complications:

• . Some infections can spread to the reproductive system, the uterus, which happens often in women. As a result, the function of the entire genitourinary system is disrupted, which can lead to infertility.
• . This is a dangerous condition in which a kidney or both kidneys lose their ability to filter urine. Infections and acute kidney diseases can lead to this condition. As a result renal failure the amount of urine excreted is sharply reduced, and the patient's condition quickly deteriorates due to intoxication.
• Kidney necrosis. The kidney tissues have small papillae that perform a filtering function. With severe inflammation and chronic diseases, they can die and be rejected, which leads to.
• Oncological diseases. , inflammatory diseases, infections, and damage to kidney tissue increase the risk of malignant tumors in the kidneys.
• Chronic diseases. Diseases in an advanced form that have become chronic are much more difficult to treat. They are accompanied by relapses over a long period of time and significantly worsen the quality of life.

To avoid diseases of the urinary system, women are advised to avoid hypothermia, dress warmly winter time, if possible, use only underwear made from natural safe fabrics, take care of personal hygiene, wash yourself at least once a day with special soft gels for intimate hygiene, do not neglect physical activity, as it prevents blood stagnation in the pelvic organs.

The urinary system includes the kidneys, ureters, bladder, and urethra. These organs are divided into urinary and urinary. The structure of the urinary system in men and women is almost the same. The difference lies only in its location and the length of the urethra: in women it is much shorter than in men and its external opening is located at the vestibule of the vagina, directly under the clitoris. In men, the canal opens at the end of the head of the penis.

Urinary organ

Kidneys(Greek - nehros) - the main organ of the human urinary system, which produces urine. Usually a person has two kidneys, but developmental anomalies are known when the body has one or three kidneys. The length of each bean-shaped bud is 10-12 cm, width - 5-6 cm, thickness - 3-4 cm. The weight of one bud ranges from 120 to 200 g.

Kidneys are a vital organ, but if for some reason a person has only one kidney, then it is able to meet the needs of the whole body (this is either a congenital absence of a kidney, or loss of function of one of the kidneys as a result of some disease)

The kidneys are located in the abdominal cavity on both sides of the spine at approximately lumbar level (with the right kidney approximately 2-3 cm lower than the left) and surrounded by a thin capsule of connective tissue, and on top of it - fatty tissue, which helps the organ to be fixed more securely. People with a thin layer of fat may develop a pathology - the so-called wandering kidney.

All blood in the body passes through the kidneys. This process takes 4-5 minutes at a flow rate of 1.2 l/min

Each kidney consists of two layers: the cortex and the medulla and has a well-developed vascular network. The cortex is located outside and has a thickness of 4-5 mm. The cortex includes the renal corpuscles (Glomeruli) and convoluted renal tubules. The cortex contains most of the structural and functional units of the kidney - nephrons.

The nephron consists of a glomerulus and a tubule. Glomerulus- this is a filtering apparatus, which is a plexus of capillaries supplied with blood from the renal arteries. A very high pressure is created in the capillaries, which is necessary for the liquid and substances dissolved in it to be filtered through the membranes. As a result, so-called primary urine is formed, the volume of which is about 150 (!) liters per day. Since the membrane practically does not allow protein molecules (albumin, globulins) to pass through due to their size and shape, the composition of primary urine is close to blood plasma.

Aretriola. In the kidney, the artery is divided into a large number of small vessels - arterioles, which bring blood to the glomerulus. Inside the glomerulus, the afferent arteriole splits into many glomerular (glomerular) capillaries. The capillaries at the exit from the glomerulus merge into the efferent arteriole, through which the blood returns to the general circulation.

Functionally, the most important part of the kidney tissue are the epithelial tubes - the urinary renal tubules. Each of these tubes begins in the cortex with a blind sac, which surrounds the choroid glomerulus in the form of a capsule; the latter, together with the capsule, forms the renal corpuscle. The urinary tubules in the cortex twist and bend in various ways to form convoluted renal tubules.

Extending beyond the cortex into the medulla, these tubules run relatively straight, forming straight renal tubules. The latter are connected to each other in groups in the medulla and flow into the papillary ducts, or collecting ducts. 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, some salts and the concentration of urea is sharply increased.

Due to the fact that each nephron acts independently of the others, the kidneys have amazing reserve capabilities: normal work can be carried out even with the functioning of a relatively small number of nephrons - from 20 to 25%. Therefore, a person can live with one kidney or part of a kidney. For the same reason, a number of signs and symptoms of kidney disease are often not detected until the lesion covers a significant portion of the kidney tissue.

Conventionally, the kidney can be divided into 2 functional parts:

1. directly kidney tissue, which performs the main function - filtering blood with the formation of urine;
2. pyelocaliceal system - that part of the kidney that is involved in the accumulation and excretion of formed urine. This system resembles a container irregular shape, covered with a mucous membrane, where there is a constant accumulation of newly formed urine before it is sent through the ureters to the bladder.

Kidney activity

Excretory (excretory) function- removal from the internal environment of the body of final and intermediate metabolic products, excess water and sodium. At the same time, the removal of nitrogen metabolism products (urea, uric acid, creatinine, etc.) is of particular importance for the normal functioning of the body. The accumulation of these substances in the blood when the excretory (excretory) function of the kidneys, which are the “purgatory” of the blood, is impaired, leads to inevitable poisoning of the body - uremia.

Participation in the regulation of the body's water balance and, accordingly, the volumes of extra- and intracellular water spaces, since the kidneys change the amount of water excreted in the urine.

Regulation of blood pressure levels. A special vasoconstrictor enzyme is formed in the kidneys - renin (ren is the Latin name for kidney), which, entering the blood, acts on one of the plasma proteins, turning it into an active vasoconstrictor substance. The kidneys also help lower blood pressure by producing certain vasodilating substances (for example, prostaglandins).

Hematopoietic function. The hormone erythropoietin, produced by the kidneys, instructs the circulatory system to replenish the blood with a fresh supply of red blood cells - red blood cells, which carry oxygen to every cell in our body.

Regulation and maintenance of constant and strictly defined levels of various proteins in the blood- the so-called oncotic blood pressure.

Maintaining water-salt metabolism and acid-base balance. In the human body, which is 80% liquid, there must be a balance between salts and water, acidic and alkaline substances. The kidneys are responsible for it, removing excess alkali and acids from the body and maintaining the osmotic pressure of the blood at a certain level, which depends on the constancy of the salts circulating in it (Na, K, Ca, Mg, Se, P, etc.).

Participation in the metabolism of calcium, phosphorus and vitamin D.

Due to anatomical features, a woman’s ureter is 2-3 cm shorter than a man’s

Urinary organs

Ureter- this is a special muscular canal 25-30 cm long that connects the renal pelvis and the bladder. The diameter of the ureter is not the same throughout its length and ranges from 3 to 12 mm. The urine formed in the kidneys flows through the ureters into the bladder, but it does not move under the influence of gravity, like ordinary water flowing down the pipes, but due to wave-like contractions of the walls of the ureter, pushing urine forward in small portions. At the junction of the ureter and the bladder there is a sphincter that opens to allow urine to pass through and then closes tightly.

Bladder and urination. The bladder is a hollow muscular organ whose task is to accumulate urine entering through the ureters and excrete it through the urethra. In an empty state, the bladder in its own way appearance resembles an empty bag, and as urine flows in, it gradually increases in size and becomes like a small inflated balloon. Once the bladder is full, nerve signals are sent to the brain and the urge to urinate occurs. Normally, we feel a distinct and strong urge when the bladder is filled to 250-300 ml.

Urination is a complex physiological process in which synchronous relaxation of the internal and external sphincters of the bladder and contraction of the detrusor (bladder muscle) with the participation of the abdominal and perineal muscles must simultaneously occur.

The daily amount of urine and its composition are variable and depend on the time of day and year, external temperature, the amount of water drunk and the composition of food, on the level of sweating, muscle work and other conditions.

The color of urine normally ranges from light yellow to deep yellow. Normally, freshly released urine is clear. In a healthy person, urine has a faint ammonia odor.

The bladder is capable of storing an average of 200-300 ml of urine. And since a healthy person urinates 4-6 times a day, therefore, during this period he secretes about 2 liters of urine

Urethra (urethra) is a tubular organ that connects the bladder to the external environment. In men and women, the urethra differs in length and width. The main function of the urethra is to remove urine from the body; in men, the seminal ducts also open into it, through which sperm is released.

At the upper poles of both kidneys there are small triangular-shaped endocrine glands - the adrenal glands. They produce the hormones adrenaline and aldosterone, which regulate the metabolism of fats and carbohydrates in the body, the functions of the circulatory system, the functioning of muscles and internal organs, and water-salt metabolism.

All diseases of the urinary system are multi-causal. First of all, a distinction is made between congenital and acquired diseases. Underdevelopment of the organs of the urinary system can be accompanied by increased blood pressure, edema, as well as metabolic disorders, which can result in the development of renal diabetes mellitus and diabetes insipidus, gout, bone damage, dementia, and blindness. Diseases are often caused by acute and chronic infectious diseases, uncontrolled use of medications. An unbalanced diet, vitamin deficiency, and alcohol abuse also increase the load on the kidneys.

During the day, about 600 g of sodium enters the glomerular filtrate, and only a few grams are excreted in the urine. If a person has to reduce consumption for any reason table salt, then the kidneys are able to cover this deficit within 30-40 days. This unique ability of the organ is extremely relevant when a patient, for medicinal purposes, needs to either limit salt intake or give it up altogether.