Urogenital system. Human urinary system, pictures and description for children

The structure of our body is such that a lot of things are constantly happening in it. different processes resulting in the formation of substances, including harmful ones. For his normal operation these substances must somehow be removed, and there are four ways:

with sweat;
with urine;
with feces;
during breathing.

Since in this article we are talking about the urinary system, 2 methods will be considered here - the removal of harmful substances from the body “with urine”.

The structure of the urinary system.

As can be seen from the figure, the main organs of the urinary (excretory) system are:

2 kidneys;
2 ureters;
bladder;
urethra(urethra).

AT integrated work these organs maintain the norm water-salt balance blood, while removing all the waste substances in the urine. That is, the main purpose of the urinary system is to purify the blood and remove the substances formed with the food consumed before it begins to turn into digestible substances. In turn, these organs can be divided into 2 types: urinary and urinary. The urinary organs are the kidneys, and the urinary organs are the 2 ureters, bladder and urethra.

The structure and function of the kidneys.

Undoubtedly, the kidneys are main body throughout the urinary system. They are located in the retroperitoneal space on both sides of the spine, approximately at the level of the lower back near the 12th thoracic and 2nd lumbar vertebrae. The kidneys are surrounded by a capsule of thin connective tissue. On top of this fabric is adipose tissue that helps the body to be securely fixed. There are cases when a person has this fatty tissue thin, as a result of which the pathology of the "wandering kidney" may occur.

The kidneys are bean-shaped with a dense structure. The length of each of them is from 10 to 12 cm, the width is from 5 to 6 cm and the thickness reaches 4 cm. Their color is dark brown or brown and each weight is about 120 to 200 grams.

In the upper part of each of the kidneys are the so-called adrenal glands (small endocrine glands). Their main task is to secrete 2 hormones: adrenaline and aldosterone. Aldosterone is responsible for potassium retention and sodium excretion from the body. Why do you think that in situations that are unusual for a person, such as those that cause feelings of fear or joy, for example, he feels more energetic? The thing is that at this time, the adrenal glands begin to intensively secrete adrenaline, which leads to an increased work of the heart, an increase in muscle performance and an increase in blood sugar levels.

The main function of the kidneys is to filter the blood. During filtration, all waste products of metabolism, including excess water and sodium, are removed from it. In general, the kidneys take on about 80% of all excreted substances from the body, and also participate in the regulation blood pressure, maintaining sodium balance in the blood, the production of red blood cells and many other processes.

Each kidney is made up of nephrons. The nephron, in turn, is a single renal corpuscle, consisting of blood vessels, sinuous and straight tubules, as well as collecting ducts that open into cups.

Human blood contains both nutrients and harmful substances. They are delivered daily through the arteries under high pressure to the kidneys. On average, about 2,000 liters of blood passes through them per day. From it, nephrons secrete 170 liters of primary urine, similar in composition to blood plasma ultrafiltrate, and only 1.5 liters are excreted from the body.

The structure and function of the ureters.

During the work of the kidneys, when urine is formed in them, it enters the bladder through the ureters. The ureters are muscular channels that push fluid in small portions due to wave-like movements. When the urine reaches Bladder the first sphincter of the bladder is included in the work. In this case, it can be compared to a one-way valve that only allows fluid to flow in one direction. It passes urine directly into the bladder.

The structure and functions of the bladder.

What is a bladder? The bladder is hollow in structure. muscular organ intended for the accumulation of urine with its subsequent excretion. In its empty state, its shape is that of a saucer; in its full state, it is like an inverted pear. Its capacity is about 0.75 liters.

The bladder consists of 2 parts:

The reservoir is where urine accumulates;
Sphincters are muscles that prevent urine from escaping from the bladder.

The first sphincter, as mentioned above, is located at the junction of the ureter and bladder. The second, is located at the junction of the bladder and urethra (urethra) and is controlled by a person spontaneously. That is, the first sphincter is responsible for filling the bladder, the second for emptying it. The walls of the bladder are composed of smooth muscle tissue, stretching when it is filled. When the bladder is full, a corresponding signal is sent to the brain. During emptying, both sphincters relax, and the muscles of the bladder wall contract, which facilitates the passage of urine through the urethra.

The structure and functions of the urinary system

Isolation is the process of removing waste products from the body. harmful products metabolism. The excretion of end products of metabolism involves the kidneys, lungs, sweat glands and intestines. CO 2 and water vapor are excreted through the lungs. A small amount of water and urea dissolved in it and mineral salts excreted through the sweat glands. Most of metabolic products are excreted through the urinary system.

The main organ of excretion is the kidneys. They have a complex structure, which reflects the complexity of their functions. In addition to the kidneys, the excretory organs include the ureter, bladder, and urethra. The kidneys are a paired organ that has a bean-like shape and weighs up to 100 g. The kidneys are located in abdominal cavity adjacent to its posterior wall at the level of the lumbar vertebrae. The kidney is covered on the outside with a very dense connective tissue capsule, which is surrounded by a fatty capsule. Kidney tissue consists of two layers: outer - cortical and inner - cerebral. The medulla forms 15-20 pyramids. In the middle of the pyramids, thin tubes pass, ending in holes in the papillae, which protrude into a small cavity - the renal pelvis. The kidney has a complex microscopic structure and contains about 1 million structural and functional units - nephrons. The nephron consists of a capsule (in the form of a two-layer bowl), which contains a tangle of capillaries, and a system of tubules. The walls of the tubules are formed by a single layer epithelial cells. The capsule is located in the cortical layer, a tortuous tubule of the first order departs from it, which goes to the medulla and, straightening, forms a loop. The loop returns to the cortical layer and there forms a convoluted tubule of the second order, flows into the collecting duct. The collecting ducts merge and open into the cavity renal pelvis from which the ureters originate.

Urine is formed from blood plasma. The process of urine formation begins in the capsules of the outer layer of the kidneys. When the blood passes through the capillaries of the glomeruli, water and substances dissolved in it are displaced (filtered) from its plasma. Filtration is carried out because the vessel that brings blood to the glomerulus, wider than the vessel, takes blood out of it. The glomerulus is created high pressure, two or more times the blood pressure in other capillaries. The filtered liquid is called primary urine. Up to 150-180 liters of primary urine can be formed in the body per day. Primary urine does not differ from blood plasma in terms of the concentration of dissolved substances. In addition to dissimilation products, it contains amino acids, glucose, ions inorganic substances etc. In primary urine, unlike blood plasma, there are no proteins, since they are not filtered. Thus, primary urine is a blood plasma filtrate, and the main filtering force is blood pressure in the capillary glomerulus.

From the capsules, the primary urine passes into the primary tubule, then into the secondary tubule, densely entwined with a network of capillaries. In this part of the nephron, most of the water and some substances are absorbed into the blood: glucose, amino acids, proteins, vitamins, and inorganic ions. The primary urine that enters the collection tube is called secondary. It contains urea uric acid, ammonia, etc. Up to 1.5 liters of secondary urine can form per day. If the kidneys are functioning normally, then there is no protein and glucose in the secondary urine. From the tubules secondary urine It collects in the renal pelvis, and then through the ureters enters the bladder. Filling the bladder leads to stretching of its wall. The nerve endings that are in the wall are irritated, the signals go to the central nervous system, and the person experiences an urge to urinate. It is carried out through the urethra and is under the control of the nervous system.

Kidney functions excretory; regulation of the volume of blood, lymph and tissue fluid, ensuring constancy osmotic pressure and ionic composition of liquids internal environment organism; regulation of blood pressure and hematopoiesis.

Violation of the kidneys. Prevention of diseases of the excretory organs

Violations or cessation of kidney function is caused by infection in the renal parenchyma. Contribute to this hypothermia of the body, kidneys, colds. Kidney disease also develops with salt poisoning. heavy metals, drugs, acids, etc.. Bad influence on the kidneys exerts consumption too spicy food. Alcohol affects the cells of the epithelium of the kidneys, disrupts or stops the formation of urine. Often, kidney stones form in diseased kidneys.

To prevent kidney disease, you should adhere to certain hygiene requirements: eat right, treat teeth, sore throat in a timely manner, harden your body, be careful with various poisons, take medicines only as directed by a doctor, observe personal hygiene.

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 move to another, and treatment is usually carried out in general for the urinary and genital organs.

Urinary system of a woman performs 2 essential functions: derivation excess fluid and the elimination of toxins and harmful substances that enter the body along with the liquid. A person consumes 1 to 2.5 liters of fluid 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”, the removal of harmful substances, which is what the urinary system does.

The urinary (urinary) system of a woman includes several important organs, vessels and arteries, the work of each of which is important for the health of the whole organism.

Main components:

. The kidneys are a paired organ that serves as a kind of filter for the body. Without the normal functioning of the kidneys, toxins accumulate in the body, poisoning occurs, and the work of all systems and organs is disrupted. The kidneys are located on the sides of the lumbar vertebrae and look like beans. It is the most important and most important organ urinary system.
Renal pelvis. This is a small funnel-shaped cavity located on the concave side of the kidney. In the pelvis, urine is collected from the kidney and excreted into the ureter.
Ureter. The ureters are 2 hollow tubes that connect the renal pelvis to bladder. Their length depends on individual characteristics organism.
Bladder. This organ is located in the lower abdomen and acts as a storage tank. It is elastic and stretches well. The bladder collects excreted urine, which is then excreted from the body.
The urethra (urethra). A tube-shaped organ that carries urine to the outside. The female urethra is located in the cavity, is not visible to the eye, and is also wider and shorter than the male. It is located in front of the vagina and performs only 1 function - the 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 fundamental differences Dont Have. All people equally have kidneys, pelvises, vena cava, etc. The only major difference is the urethra. In men, it performs 2 functions: seminal and urinary. In women, the urethra is solely responsible for the excretion 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 the small length, the urethra in women is more prone to inflammatory diseases. For the same reason, inflammation of the urethra in women is much more likely to lead 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, the bladder of women has a somewhat saddle shape.

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

The kidneys filter the blood, absorbing all harmful substances. Toxins are then converted into urine, which is excreted in the pelvis, from the pelvis through the ureters enters the bladder. So that a person does not have to urinate with each such filtration, the bladder accumulates urine. When it fills, a person begins to reflex the urge to urinate, and then the urine is excreted through the urethra.

Useful video - Diseases of the urinary system:

An important role in the process of excretion and excretion of urine is played by the muscles of the bladder. 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 expelled voluntarily when the bladder is full. It acts as a castle.

A feature of the urinary process is that it is controlled by the human mind and, in the absence of diseases, does not occur arbitrarily. But this control is not innate; children learn to control their urination during the first 1-2 years of life. In girls, the learning process is often faster.

Possible diseases of the urinary system of a woman

Diseases of the urinary system are often associated with the genital organs, genital 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. It occurs quite often in women, but in men it is more acute. The main symptoms of urethritis: pain and discomfort during urination, discharge from the urethra and vagina with pungent odor, cloudy urine or urine with a strong unpleasant odor.
Cystitis. In women, cystitis usually occurs simultaneously with urethritis. Inflammation from the urethra quickly passes to the bladder. Most often, it is the bacteria that have entered through the urethra that lead to cystitis. Symptoms of cystitis: pain in the lower abdomen in women, which is aggravated by urination, nausea, fever, impaired urination, 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 high fever (up to 40 degrees), fever, chills, vomiting and nausea, pain in the lumbar region.
Amyloidosis. In this disease, damage to the tissues of the kidneys is secondary. The disease is accompanied by a metabolic disorder, as a result of which the protein settles in the tissues of the kidneys. it dangerous disease, which leads to disruption of the work of all systems and organs, and can also lead to death.
. A cyst is a benign, hollow mass filled with fluid. Large cysts disrupt the process of blood circulation and outflow of urine can lead to inflammatory process in kidney tissues.

It is desirable to treat diseases of the urinary system at the most early stages, because in running form they lead to serious complications and disorders not only of the urinary and sexual functions, but also of the functions of all body systems.

Possible complications:

. Some infections can be transferred to 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.
. it dangerous state in which the kidney or both kidneys lose their ability to filter urine. Infections can lead to this condition, acute diseases kidneys. As a result kidney failure the amount of urine separated is sharply reduced, and the patient's condition is rapidly deteriorating due to intoxication.
Necrosis of the kidneys. In the tissues of the kidneys there are small papillae that perform a filtering function. At severe inflammation and chronic diseases they can die off and be rejected, which leads to.
Oncological diseases. , inflammatory diseases, infections, damage to kidney tissue increase the risk of malignant tumor in the kidneys.
Chronic diseases. Diseases in a neglected form that have passed into chronic form are much more difficult to treat. They are accompanied by relapses for a long time and significantly worsen the quality of life.

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

The human body is a “full-cycle factory”, constantly producing many substances, many of which are harmful and must be eliminated from the body. There are several ways to do this. All harmful substances are excreted with breath, sweat, feces and urine. Thus, the urinary system is one of the main ways to get rid of everything harmful and unnecessary to the body. Its structure and diseases will be discussed today.

The most important organ that plays a leading role in detoxification processes. It is paired, but you can exist with one, and when genetic disorders the kidney may be doubled. Are parenchymal organ. Located in the lumbar region. The structure of the body is quite complex. The organ consists of:

Capsules and barks. The nephrons are immersed in it, in which the primary urine is formed. A glomerulus of capillaries is hidden in the nephron, which is needed to filter water, urea and layers.
medulla. Primary urine passes through its tubules. They also carry out the return of glucose and the remaining water to the capillaries. After that, secondary urine remains, which enters the pyramids of the kidney.
renal pelvis. Secondary urine enters it from the pyramids and is sent to the ureters.
Kidney gate. Here, an artery enters the organ and a vein exits. They are also the entrance to the ureters.
Inside the organ are: the renal column, adipose tissue, papilla, renal sinus and calyces (small and large).

Normal kidney weight is about 200 g, thickness is about 4 cm, length is from 10 cm to 12. If right kidney slightly below the left is normal.

The main functions of the urinary system are:

getting rid of unnecessary and waste products of metabolism;
maintenance of homeostasis (meaning the water-salt balance);
hormonal function (carried out by the adrenal glands).

Several organs work for all this at once:

kidneys;
ureters;
bladder;
urethra.

There are also secondary, but no less important organs, such as the aorta and the inferior vena cava, as well as the adrenal glands, which are glands that synthesize hormones, including adrenaline and norepinephrine.

Ureters

They are thin and long tubes extending from the pelvis and flowing into the bladder. The ureters connect the bladder and pelvis. The walls of the organ consist of mucous (stratified epithelium), muscular and adventitious (connective tissues) layers. They are located in the retroperitoneal space, have a length of 28 - 34 cm, but the left one is usually slightly longer, due to the location of the kidneys. The basis of the organ is smooth muscle, the outer layer is connective tissue, inside the epithelium. It has the ability to peristalsis, in the region of the mouth, in the middle of the organ and in the region of connection with the pelvis, it has constrictions.

Bladder

A fairly large organ located in the pelvis. It is an organ of smooth muscle, which is lined with epithelium inside. From above it is covered with a peritoneum. Comprises:

necks;
side, back and front walls;

The orifices of the ureters are located on back wall organ. It has the form of a bag, reaching a volume of 200 - 400 ml when filled. Urine accumulates for about three hours, when the walls contract, it leaves the urethra.

Urethra

Also called the urethra. In women and men, this organ has differences in structure:

It is a tubular and unpaired organ.
Consists of smooth muscle that is lined internally epithelial tissue. Its task is to bring external environment urine. Like the ureters, it has three layers. In men, it is also needed for ejaculation and is located in the penis. The female urethra is wider, well stretched, slightly shorter and easily affected by infection.

Diseases of the urinary system

Unfortunately, all organs of the urinary system are prone to disease. Here are the most common ailments of this organ system.

Bladder:

hyperactive;
neurogenic;
(including interstitial);
hernia;
diverticulum;
Marion's disease;
tumors and cancer;
sclerosis of the neck of the bladder;
stenosis of the neck of the bladder;
structural anomalies.

Ureters:

strictures;
stones in the ureters;
Ormond's disease;
reflux vesicoureteral;
ureterocele;
neuromuscular dysplasia;
empyema of the stump of the organ;
tuberculosis of the ureters;
tumors.

Kidneys:

structural anomalies;
pyelonephritis chronic and acute;
cyst;
nephroptosis (omission);
glomerulonephritis;
hydronephrosis;
jade apostematous;
paranephritis;
abscess;
pyonephrosis;
carbuncle;
nephropathy (diabetic, during pregnancy);
acute and chronic renal failure;
tumors;
tuberculosis;
syndrome prolonged compression kidneys.

Urethra:

fistulas;
urethritis;
anomalies (congenital narrowing, doubling, epispadias, hypospadias);
stricture;
prolapse (including the mucous membrane);
diverticulum;
papillomas (they are condylomas);
polyps;
angioma;
fibroma;
caruncle;
trauma;
tumors are malignant.

To diagnose any ailments of the urinary system, examinations such as laboratory diagnostics(urine and blood tests), cystoscopy, radiological methods, ultrasound procedure, MRI, CT. Symptoms can be very different, but with many ailments of the urinary system, urination disorders, pain and changes can be noted. appearance urine.

The urinary system is one of the largest organ systems in our body. Its main task is to free the body from toxins. Not only the kidneys work for this, but also the ureters, bladder and urethra.

You can also learn about the urinary system in this video.

The human urinary system performs the function of removing toxins, unnecessary, harmful compounds, while remaining in the body required amount mineral salts and water. This task is realized through the formation of urine in the kidneys in a certain volume and with a certain concentration.

The structure of the urinary system.

Its structure includes organs that produce urine (kidneys), accumulate and excrete urine from the body (bladder, ureters).

The kidneys, located in the space behind the peritoneum on both sides of the spine, are bean-shaped. Left kidney is slightly above the right. The top edges of this paired organ close to the spine, the lower ones are distant.

In the kidney, the lower and upper poles, the inner and outer edges are determined. In the center of the inner edge there is a gate (recess). Through them, nerves and arteries enter the organ, the ureter and vein exit. The combination of these elements forms the renal stalk.

A fatty capsule, its own membrane and connective tissue fascia surround each kidney. The substance of the kidney includes two layers - cerebral and cortical. The first is represented by twelve to fifteen cone-shaped formations. They are called pyramids. The cortex seeps between the nearby pyramids. The cortical layer has a thickness of four to thirteen millimeters.

The urinary system has several regulatory mechanisms.

The amount of water contained in the body affects the concentration of urine. An excessive volume of water contributes to the inhibition of secretion in the pituitary gland, which controls the absorption of salts and water. With a lack of water, sensitive special education(osmoreceptors). In this case, ADH is released into the blood, which contributes to the reabsorption (reabsorption) of water.

The urinary system carries out, together with urine, the excretion of water, salt, and urea. These components are also excreted through the lungs, skin, intestines, salivary glands, however, they are not able to replace the kidneys.

Including the stage of filtering fluid from the blood, secretion and reverse suction, carried out in nephrons ( constituent parts kidney tissue). Each nephron contains the renal (Malpighian) bodies, which provide the filtration process, and the urinary tubules. The body is represented by a hemispherical double-walled bowl. The gap between its walls covers the capillary glomerulus. A tubule also emerges from the gap.

Intravascular pressure (70-90 mm Hg) contributes to the seepage of the liquid part of the blood into the nephron capsule. This process is called filtration, the leaked liquid, respectively, is called "filtrate" (primary urine).

The urinary system forms a filtrate, consisting mainly of water. The concentration of low molecular weight substances in the primary urine is approximately the same as in the blood plasma. As the filtrate moves through the tubules, its composition is constantly changing, eventually becoming the final urine. The average volume of urine is about one and a half liters per day.

The urinary system also includes the bladder in its structure. This organ performs the function of storing urine. A powerful shell of muscles is located in the wall of the organ. With its reduction, the volume of the bladder cavity decreases. In the region of the ureteral orifices, inner hole the urethra contains sphincters (compressors). They regulate the flow of urine.

Tubes (ureters) fit to the bottom of the bladder.

The excretion of urine to the outside is carried out through the urethra, which exits the bladder.