Excretory system of man

Excretory (excretory) system is a set of organs that perform excretion.

The normal vital activity of the organism is characterized by the constancy of the internal environment. In particular, its parameters include the total content and ratio in the volumes of water spaces, which depends on the osmotic and hydrostatic pressure. To maintain the consistency of these parameters, it is necessary to clearly match the withdrawal of active osmotic substances and water to the level of their consumption.

Functions of the excretory system are partly performed by the lungs, the gastrointestinal tract and the skin. However, the main excretory organs are the kidneys.

The urinary system consists of organs performing the task of urinary formation and excretion (urinary organs) and organs involved in reproduction (the reproductive organs). Both groups of organs are connected functionally and morphologically. The excretory system includes the kidneys, ureter, bladder and urethra.

The kidneys are located in the retroperitoneal area on both sides of the spinal column. The right kidney is normally somewhat lower. This is due to the fact that the liver is above it. The kidneys perform the task of forming a fluid, which as a result becomes urine.

The structure of the kidneys includes a huge number of nephrons (very thin convoluted tubules). In the lumens of nephron capsules, primary urine filtration takes place. In their proximal convoluted tubules, there is absorption of amino acids, protein, calcium, glucose, phosphorus from the primary urine. The structure of the kidneys contains straight thin-walled sections, passing into loops, which consist of descending sections, bends and ascending areas. Through the lining of the descending sections of loops of flat cells, water is sucked, in the ascending areas, water is accumulated and sodium is lost. Short distal departments are responsible for further isolation into the tissue fluid of sodium and for absorption of a large volume of water.

Distal, convoluted tubules flow into the collecting ducts, through which urine penetrates into the renal pelvis (in fact, the enlarged ends of the ureters). The excretory system carries urine output into the urinary bladder and then outward from the body.

The urge to urinate is accompanied by relaxation of the musculature of the external and internal sphincter and contraction of the muscles of the walls of the bladder. It is believed that the excretory system works normally, with urination from four to six times a day with a single accumulation of urine in an amount of 250-300 ml.

Diseases of the excretory system can be manifested by pain in the lumbar region, edema formation, changes in the amount and color of urine, painful urination. It is necessary to note the existence of atypical and malosymptomatic ailments. Often patients complain of dizziness, drowsiness, headache, weakness, decreased performance.

In many cases, the causes of diseases of the urinary system are infections.

Pain sensations of different intensity and degree of manifestation may be associated with the formation of stones or a tumor.

Normal is a clear, straw-yellow color of urine. With feverish illnesses, its color may be brownish yellow with a brick sediment. The blood color of urine may indicate the presence of kidney stone disease, tumors and kidney trauma. When taking medicines or vitamins, urine can also change color.

Exposure of high content of leukocytes in the urine may indicate the presence of inflammatory processes in the kidneys and lower urinary tract.

A sharp decrease in the mass of the active parenchyma, as a rule, entails renal failure. In this case, significant violations or complete loss of the basic functions of the kidneys.