Liver as the gland of the digestive system. Functions of the liver. Structure of the liver.

The liver is the largest gland of the organism (weight reaches 1.5 kg), which is located in the right upper quadrant. The liver itself is divided into two parts or parts: left and right. Between the lobes are the gates of the liver, through which blood vessels enter it (including the portal vein that collects and carries the blood of the intestines), nerves, lymphatic ducts, and the bile duct emerges.

The liver is a kind of storage of substances and a biochemical laboratory of the body. So, for example, the products of digesting carbohydrates (mono-sugar) in the liver are converted into glycogen, which accumulates in its cells. When there is a need for additional energy (for example, under physical exertion), liver glycogen is processed into sugar dextrose and sent to the muscles and other tissues of the body with blood and is included in the adenosine triphosphate (ATP), which is the energy carrier. also processes of hemolysis (destruction) of blood erythrocytes, die from hemoglobin of such erythrocytes, among other things, iron (heme) is released, which accumulates in specialized cells of the parenchyma of the stove It can be gradually used in the synthesis of new red blood cells in the red bone marrow.3-33321
The most important function of the liver is to neutralize the toxins that form in the body or enter it with food or water.Thoxins of tea, coffee, cocoa, alcohol , tobacco, under the influence of liver cells, turn into non-harmful substances and are removed, through the blood, through the kidneys.Some toxic end products of digestion of food in the intestine (for example, indole containing sulfur and are a by-product of incomplete ererabotki excess egg protein, meat or beans) in hepatic detoxification and disposal be composed of bile. Bile contains 90% water and 10% inorganic and organic substances. The composition of inorganic substances of bile includes bile pigments of bilirubin and biliverdin, ions of potassium, sodium, etc. The organic substances of bile are represented by glycocholic and glkkoholetovoyu bile acids, cholesterol, lecithin, tsuucin and other substances.

The structural and functional unit of the liver is highly specialized hepatocyte cells, forming the so-called hepatic beams. Each of these beams has two rows of hepatocytes, which, on the one hand, contact the capillaries of the venous blood channel, and from the second they open into the capillary of the bile duct. Superfluous substances harmful to the body contained in the blood pass through the hepatocytes and, due to the chemical reactions of decomposition, they turn into bile removal products. But bile in the body is not only an extra product, which must be removed, since it also has a certain role in the regulation and implementation of the processes of digesting food. So, for example, despite the fact that there are no enzymes in the bile, it takes part in the processes of activating lipase and other enzymes of intestinal juice. Secondly, bile causes emulsification of fats to the smallest droplets, which are better suited to the action of lipases. Bile also actively influences the processes of absorption by the walls of the intestines of food digestion products, and finally, bile promotes the enhancement (through the blood) of pancreatic and gastric juice. The amount of bile produced since the birth of a child is already sufficient to emulsify the fat of milk. In the first years of the child's life, the bile acid content in the bile is relatively high. In the preschool and primary school age, the acidity of bile is significantly reduced, and in adults again significantly increases. The specified dynamics testifies that for preschool and younger children school age fatty food is too heavy, whereas protein and carbohydrate is the most suitable.