The urinary system is an organic complex that produces, accumulates and releases urine. The main organ of this system is the kidney. In fact, urine is a product that is formed due to the processing of blood plasma. Therefore, urine also refers to organic biomaterials. From the plasma, it is distinguished only by the absence of glucose, proteins and some trace elements, as well as the content of the exchange products. That is why urine has such a specific shade and odor.
Blood filtration in the kidneys
To understand the mechanism of blood purification and urine formation, one must have an idea of the structure of the kidney. This paired organ consists of a huge number of nephrons, in which urination occurs.
The main renal functions are:
- Urination;
- Purification of blood, excretion of drugs, metabolites, etc.;
- Regulation of electrolyte exchange;
- Control of pressure and volume of circulating blood;
- Maintain acid-base balance.
Each kidney has a bean-shaped form. On each kidney there is a kind of cavity, which is also called the gate. They lead to a fat-filled space or sinus. There is also a cup-and-pelvic system, nerve fibers and a vascular system. From the same gate, the vein and artery of the kidney, as well as the ureter, exit.
Each kidney consists of a set of nephrons, which are a complex of tubules and a glomerulus. The filtration of blood occurs directly in the renal corpuscle or glomerulus. It is there that urine is filtered from the blood and leaves into the bladder.
In the video, the structure of the kidneys
Where the
occurs The kidney is placed in a capsule, beneath which is a granular layer called a cortex, and underneath is a brain substance. The brain layer is folded into the kidney pyramids, between which there are columns extending to the side of the kidney sinuses. On the tops of these pyramids are located papillae, which empty the pyramids, removing their contents into small cups, then into large ones.
Each person can have a different number of cups, although in general 2-3 large cups branch into 4-5 small cups, one small cup necessarily surrounding the papilla of the pyramid. From a small calyx, urine falls into a large one, and then into the ureter and urinary structures.
Blood is supplied to the kidneys along the renal artery, which branches into smaller vessels, then blood penetrates into the arterioles, dividing into 5-8 capillaries. So the blood enters the glomerular system, where the filtration process is carried out.
Glomerular filtration - definition of
Filtration in the glomerulus of the kidneys follows a simple principle:
- First of the glomerular membranes under hydrostatic pressure, the liquid is squeezed / filtered( ≈ 125 ml / min);
- Then the filtered liquid passes through the nephrons, most of it in the form of water and the necessary elements is returned to the blood, and the rest is formed into the urine;
- The average rate of urine formation is of the order of 1 ml / min.
The glomerulus of the kidney produces a filtration of blood, purifying it from various proteins. During the filtration, primary urine is formed.
The speed of glomerular filtration is the volume of the primary urine formed in the kidney structures per minute. The normal rate is the filtration rate of 110 ml / min in women and 125 ml / min in men. These indicators act as reference points, which are subject to correction in accordance with weight, age and other indicators of the patient. [/ Alert]
Failure of filtration
For a day, nephrons are filtered to 180 L of primary urine. All the blood in the body has been cleared by the kidneys 60 times a day.
But some factors are capable of provoking a violation of the filtration process:
- Pressure reduction;
- Urinary disorders;
- Narrowing of the artery of the kidney;
- Traumatization or damage to the membrane performing filtering functions;
- Increased oncotic pressure;
- Decrease in the number of "working" glomeruli.
Such conditions most often cause filtering failures.
How to determine violation of
Violation of filtration activity is determined by calculating its rate. To determine how much the filtration can be restricted in the kidneys by various formulas. In general, the process of determining the speed is reduced to comparing the level of a certain control substance in the urine and blood of the patient.
The more inulin in urine in relation to its level in the blood, the larger the volume of filtered blood. This indicator is also referred to as inulinous clearance and is considered as the value of purified blood. But how to calculate the rate of filtration?
The formula for calculating the glomerular filtration rate of the kidneys is as follows:
= GFR( mL / min),
where Min is the amount of inulin in the urine, Pin is the plasma inulin content, Vmoch is the final urine volume, and GFR is the glomerular filtration rate.
Renal activity can also be calculated using the Cockcroft-Gault formula, which looks like this:
When measuring female filtration, the result should be multiplied by 0.85.
Quite often in clinical conditions, when measuring GFR, creatinine clearance is used. A similar study is also called Reborg's breakdown. Early in the morning, the patient drinks 0.5 liters of water and immediately empties the bladder. After that, every hour you need to urinate, collecting urine in different containers and noting the duration of each urination.
The venous blood is then examined and the glomerular filtration is calculated using a special formula:
Fi =( U1 / p) x V1,
where Fi is the glomerular filtration, U1 is the control component content, p is the level of creatinine in the blood, and V1 is the duration of the urinary test. According to this formula, every hour is calculated, throughout the day.
Symptoms of
Symptoms of glomerular filtration disorders are usually reduced to changes in quantitative( increase or decrease in filtration) and qualitative( proteinuria) character.
Additional features include:
- Pressure reduction;
- Renal stasis;
- Hyperthermia, especially in the limbs and face;
- Urinary disorders, such as a decrease or increased frequency of desires, the appearance of an uncharacteristic sediment or color changes;
- Pain in the lumbar region
- Blood accumulation in various kinds of metabolites, etc.
Pressure drop usually occurs when shock conditions or myocardial insufficiency.
How to improve the filtration of
To restore the filtration of the kidneys is extremely necessary, especially if there is persistent hypertension. With the urine, excess electrolytes and fluids are washed out of the body. It is their delay and causes an increase in blood pressure.
For the improvement of renal activity, in particular, glomerular filtration, specialists can prescribe the use of drugs like:
- Theobromine is a weak diuretic, which by increasing renal blood flow increases filtration activity;
- Euphyllin is also a diuretic containing theophylline( alkaloid) and ethylenediamide.
In addition to taking medications, it is necessary to restore the patient's general well-being, restore immunity, normalize blood pressure, etc.
Not bad help in increasing renal activity and folk methods such as watermelon diet, dog rose broth, diuretic broths and herbal infusions, teas, etc. But before you would do anything, you need after consulting a nephrologist.