Kidneys

Kidneys – the pair parenchymatous bodies forming urine.

Kidney structure

Kidneys are located on both sides of a backbone in retroperitoneal space, that is the leaf of a peritoneum covers only their front party. Borders of an arrangement of these bodies widely vary even within norm. Usually left kidney is located a little above right.

The periblast of body is formed by the fibrous capsule. The fibrous capsule is covered by fatty. Renal covers together with a renal bed and the renal leg consisting of blood vessels, nerves, an ureter and a pelvis belong to the fixing kidney device.

Anatomically the structure of a kidney reminds a type of a bean. In it allocate an upper and lower pole. The concave inner edge which deepening the renal leg enters is called gate.

On a section the structure of a kidney is heterogeneous – the blanket of dark red color is called cortical substance which is formed by renal little bodies, distal and proximal tubules of nephron. Thickness of a bast layer varies from 4 to 7 mm. The deep layer of light gray color is called a medulla, it not continuous, is formed by the triangular pyramids consisting of collective tubules, papillary channels. Papillary channels come to an end on a top of a renal pyramid with papillary openings which open in renal cups. Cups merge and form a uniform cavity – a renal pelvis which in hiluses renalis proceeds in an ureter.

At the microlevel of a structure of a kidney allocate its main structural unit – nephron. Total quantity of nephrons reaches 2 million. Are a part of nephron:

• Vascular ball;
• Ball capsule;
• Proximal tubule;
• Henle's loop;
• Distal tubule;
• Collective tubule.

The vascular ball is formed by network of capillaries in which filtering from plasma of primary urine begins. Membranes through which filtering is carried out have so narrow time that do not pass through them normal proteinaceous molecules. At advance of primary urine on system of tubules and tubules from it ions, glucose and amino acids, important for an organism, are actively soaked up, and the fulfilled products of exchange remain and concentrate. Already secondary urine comes to renal cups.

Functions of kidneys

The main function of kidneys – secretory. They form urine with which of an organism toxic decomposition products of proteins, fats, carbohydrates are removed. Thus in an organism the homeostasis and acid-base equilibrium, including the maintenance of the vital potassium ions, sodium is supported.

Where the distal tubule adjoins to a ball pole, the so-called "dense spot" where special juxtaglomerular cells synthesize substances a renin and erythropoetin is located.

Formation of a renin is stimulated with lowering of blood pressure and sodium ions in urine. The renin promotes transformation of angiotensinogen into the angiotensin capable to increase pressure due to narrowing of blood vessels and strengthening of sokratitelny ability of a myocardium.

Erythropoetin stimulates formation of cells of red blood – erythrocytes. Formation of this substance is stimulated by a hypoxia – decrease in content of oxygen in blood.

Diseases of kidneys

The group of diseases which break secretory function of kidneys is quite extensive. An infection in different departments of kidneys, an autoimmune inflammation, disbolism can be etiologies. Often pathological process in kidneys is a consequence of other diseases.

Glomerulonephritis – an inflammation of renal balls in which urine filtering is carried out. Infectious and autoimmune processes in kidneys can be the cause. At this disease of kidneys integrity of the filtering membrane of balls is broken, and proteins and blood cells begin to get into urine.

The main symptoms of a glomerulonephritis are hypostases, increase in arterial pressure and detection of a large number of erythrocytes, cylinders and protein in urine. Treatment of kidneys at a glomerulonephritis surely includes anti-inflammatory, antibacterial, antiagregantny and corticosteroid drugs.

Pyelonephritis – an inflammatory disease of kidneys. The pyelocaliceal device and intersticial (intermediate) fabric is involved in process of an inflammation. Most often the pyelonephritis reason – microbic infection.

The general reaction of an organism to an inflammation in the form of fever, feeling sick, headaches, nausea will be symptoms of pyelonephritis. Such patients complain of back pains which amplify at percussion in kidneys, release of urine can decrease. In analyses of urine there are inflammation signs – leukocytes, bacteria, slime. If the disease repeats often, that is risk of its transition to a chronic form.

Treatment of kidneys at pyelonephritis without fail includes antibiotics and uroseptik, sometimes several courses in a row, diuretic, disintoxication and symptomatic means.

The urolithiasis is characterized by formation of stones in kidneys. The main reason for it is disbolism and change of acid-base properties of urine. Danger of finding of stones in kidneys is that they can block urinary tract and break urine outflow. At stagnation of urine renal fabric can easily be infected.

The back pains (can be only on the one hand) amplifying after an exercise stress will be symptoms of an urolithiasis. The urination is speeded up and causes pain. At hit of a stone from a kidney in an ureter pain extends down, to the inguinal area and generative organs. Such attacks of pain are called renal colic. Sometimes after its attack in urine small stones and blood are found.

Finally to get rid of stones in kidneys, it is necessary to adhere to the special diet reducing a lithogenesis. At the small sizes of stones in treatment of kidneys use special drugs for their dissolution on the basis of urodezoksikholevy acid. Some collecting herbs (an immortelle, cowberry, a ptarmigan-berry, fennel, a horsetail) possess medical action at an urolithiasis.

When stones rather large or do not give in to dissolution, for their crushing use ultrasound. In case of emergency surgical removal them from kidneys can be necessary.