Iron in the human body: why it is needed and why iron deficiency is dangerous. What is the name of the largest human gland? The largest human gland
LIVER
the largest gland in the body of vertebrates. In humans, it makes up about 2.5% of body weight, on average 1.5 kg in adult men and 1.2 kg in women. The liver is located in the upper right part abdominal cavity; it is attached by ligaments to the diaphragm, abdominal wall, stomach and intestines and is covered with a thin fibrous membrane - Glisson's capsule. The liver is a soft but dense organ of a red-brown color and usually consists of four lobes: a large right lobe, a smaller left lobe, and much smaller caudate and quadrate lobes that form the posterior lobe. bottom surface liver.
LIVER is the largest gland in the human body, performing many functions. Ligaments fix its position in the upper right part of the abdominal cavity. The structure of the liver includes several lobes, each of which consists of functional units - lobules. Liver cells secrete bile needed for digestion into intralobular bile canaliculi. Bile is transported to the intestines through the common bile duct or gallbladder, where it is stored for future use. Nutrition of the liver tissue is provided by blood flowing through hepatic artery. The portal vein brings blood containing absorbed digestive products, which are further processed in the liver. All incoming blood enters the lobular capillaries - sinusoids. Flowing through them, it washes the liver cells and exits through the central, then interlobular, and then hepatic veins into the inferior vena cava.
Functions. The liver is an organ necessary for life with many various functions. One of the main ones is the formation and secretion of bile, clear liquid orange or yellow. Bile contains acids, salts, phospholipids (fats containing a phosphate group), cholesterol and pigments. Bile salts and free bile acids emulsify fats (i.e. break them into small droplets), making them easier to digest; convert fatty acids into water-soluble forms (which is necessary for absorption as fatty acids, and fat-soluble vitamins A, D, E and K); have antibacterial effect. All nutrients, absorbed into the blood from digestive tract, - products of digestion of carbohydrates, proteins and fats, minerals and vitamins - pass through the liver and are processed in it. At the same time, some amino acids (protein fragments) and some fats are converted into carbohydrates, so the liver is the largest “depot” of glycogen in the body. It synthesizes blood plasma proteins - globulins and albumin, and also undergoes amino acid conversion reactions (deamination and transamination). Deamination - the removal of nitrogen-containing amino groups from amino acids - allows the latter to be used, for example, for the synthesis of carbohydrates and fats. Transamination is the transfer of an amino group from an amino acid to a keto acid to form another amino acid (see METABOLISM). Also synthesized in the liver ketone bodies(products of fatty acid metabolism) and cholesterol. The liver is involved in regulating glucose (sugar) levels in the blood. If this level increases, liver cells convert glucose into glycogen (a substance similar to starch) and store it. If the blood glucose level drops below normal, glycogen is broken down and glucose enters the bloodstream. In addition, the liver is capable of synthesizing glucose from other substances, such as amino acids; this process is called gluconeogenesis. Another function of the liver is detoxification. Medicines and other potentially toxic compounds can be converted into a water-soluble form in liver cells, which allows them to be excreted in bile; they can also be destroyed or conjugate (combine) with other substances to form harmless products that are easily excreted from the body. Some substances are temporarily deposited in Kupffer cells (special cells that absorb foreign particles) or in other liver cells. Kupffer cells are particularly effective at removing and destroying bacteria and other foreign particles. Thanks to them, the liver plays important role V immune defense body. Possessing a dense network of blood vessels, the liver also serves as a blood reservoir (it constantly contains about 0.5 liters of blood) and is involved in the regulation of blood volume and blood flow in the body. In general, the liver performs more than 500 different functions, and its activity cannot yet be reproduced artificially. Removal of this organ inevitably leads to death within 1-5 days. However, the liver has a huge internal reserve, it has an amazing ability to recover from damage, so humans and other mammals can survive even after 70% of the liver tissue is removed.
Structure. The complex structure of the liver is perfectly adapted to perform its unique functions. The lobes consist of small structural units - lobules. In the human liver there are about one hundred thousand of them, each 1.5-2 mm long and 1-1.2 mm wide. The lobule consists of liver cells - hepatocytes, located around the central vein. Hepatocytes are united into layers one cell thick - the so-called. liver plates. They diverge radially from the central vein, branch and connect with each other, forming complex system walls; the narrow gaps between them, filled with blood, are known as sinusoids. Sinusoids are equivalent to capillaries; passing one into another, they form a continuous labyrinth. The hepatic lobules are supplied with blood from the branches of the portal vein and hepatic artery, and the bile formed in the lobules enters the tubular system, from which into bile ducts and is excreted from the liver.
The hepatic portal vein and hepatic artery provide the liver with an unusual, dual blood supply. Nutrient-rich blood from the capillaries of the stomach, intestines, and several other organs is collected in the portal vein, which, instead of carrying blood to the heart like most other veins, carries it to the liver. In the liver lobules, the portal vein breaks up into a network of capillaries (sinusoids). The term “portal vein” indicates the unusual direction of blood transport from the capillaries of one organ to the capillaries of another (the kidneys and pituitary gland have a similar circulatory system). The second source of blood supply to the liver, the hepatic artery, carries oxygenated blood from the heart to the outer surfaces of the lobules. The portal vein provides 75-80%, and the hepatic artery 20-25% of the total blood supply to the liver. In general, about 1500 ml of blood passes through the liver per minute, i.e. quarter cardiac output. Blood from both sources ultimately enters the sinusoids, where it mixes and flows to the central vein. From the central vein, the outflow of blood to the heart begins through the lobar veins into the hepatic vein (not to be confused with portal vein liver). Bile is secreted by liver cells into the smallest tubules between the cells - bile capillaries. By internal system tubules and ducts it collects into the bile duct. Part of the bile goes directly into the common bile duct and is poured into small intestine, but most of the cystic duct returns for storage to the gallbladder - a small sac with muscle walls, attached to the liver. When food enters the intestines, the gallbladder contracts and releases the contents into the common bile duct, which opens into the duodenum. The human liver produces about 600 ml of bile per day.
Portal triad and acini. The branches of the portal vein, hepatic artery and bile duct are located nearby, at the outer border of the lobule and form the portal triad. At the periphery of each lobule there are several such portal triads. The functional unit of the liver is the acinus. This is the part of tissue that surrounds the portal triad and includes the lymphatic vessels, nerve fibers and adjacent sectors of two or more lobules. One acini contains about 20 liver cells located between the portal triad and central vein each slice. In a two-dimensional image, a simple acinus looks like a group of vessels surrounded by adjacent sections of lobules, and in a three-dimensional image it looks like a berry (acinus - lat. berry) hanging on a stalk of blood and bile vessels. Acinus, the microvascular framework of which consists of the above circulatory and lymphatic vessels, sinusoids and nerves, is the microcirculatory unit of the liver. Liver cells (hepatocytes) have the shape of polyhedra, but they have three main functional surfaces: sinusoidal, facing the sinusoidal channel; tubular - involved in the formation of the wall of the bile capillary (it does not have its own wall); and intercellular - directly adjacent to neighboring liver cells.
Liver dysfunction. Since the liver has many functions, it functional disorders extremely varied. Liver disease increases the load on the organ and can damage its structure. The process of liver tissue restoration, including the regeneration of liver cells (formation of regeneration nodes), has been well studied. It has been discovered, in particular, that with liver cirrhosis, perverted regeneration of liver tissue occurs with an incorrect arrangement of vessels formed around cell nodes; As a result, blood flow in the organ is disrupted, which leads to the progression of the disease. Jaundice, manifested by yellowness of the skin, sclera (the white of the eyes; here the color change is usually most noticeable) and other tissues, - common symptom in liver disease, reflecting the accumulation of bilirubin (the reddish-yellow pigment of bile) in body tissues.
See also
HEPATITIS;
JAUNDICE;
GALL BLADDER ;
CIRRHOSIS.
Animal liver. If the human liver has 2 main lobes, then in other mammals these lobes can be divided into smaller ones, and there are species in which the liver consists of 6 and even 7 lobes. In snakes, the liver is represented by one elongated lobe. The liver of fish is relatively large; in those fish that use liver oil to increase buoyancy, it is of great economic value due to its significant content of fats and vitamins. Many mammals, such as whales and horses, and many birds, such as pigeons, lack a gallbladder; however, it is present in all reptiles, amphibians and most fish, with the exception of a few species of sharks.
LITERATURE
Green N., Stout W., Taylor D. Biology, vol. 2. M., 1996 Human Physiology, ed. Schmidt R., Tevsa G., vol. 3. M., 1996
Collier's Encyclopedia. - Open Society. 2000 .
Synonyms:See what "LIVER" is in other dictionaries:
Liver- (hepar) (Fig. 151, 158, 159, 165, 166) is the largest gland human body, its weight reaches 1.5-2 kg, and its size is 25-30 cm. It is located in the upper abdominal cavity under the dome of the diaphragm, occupying mainly... ... Atlas of Human Anatomy
LIVER- LIVER. Contents: I. Liver ashtomia............... 526 II. Liver histology......................... 542 III. Normal physiology liver...... 548 IV. Pathological physiology liver..... 554 V. Pathological anatomy liver...... 565 VI.… … Big medical encyclopedia
- (hepar), digestive gland of some invertebrates and all vertebrates. Among invertebrates, it is found in horseshoe crabs, arachnids, crustaceans, mollusks, and a number of echinoderms (starfish and lilies). Represents a hollow outgrowth of the average... ... Biological encyclopedic dictionary
liver- - is the most voluminous of the glands of the appendages of the digestive tract: indeed, its weight is 1500 grams. It is located on the highest tier of the right side of the abdominal cavity and extends into the epigastric region. Through the underside of the liver... ... Universal additional practical explanatory dictionary I. Mostitsky
Liver- person. LIVER, a large gland in the abdominal cavity. Participates in the metabolism of proteins (synthesizes many blood proteins), lipids, carbohydrates (regulates blood sugar levels), in water and salt metabolism, in the synthesis of vitamins A and B12, in detoxification... ... Illustrated Encyclopedic Dictionary
PECHENKIN LIVER PECHENITSYN PECHENIN PECHENIKOV PECHINKIN LIVER PECHENKIN LIVER PECHENITSYN PECHENIKOV PECHINKIN From the name of the organ human body liver (E) More correctly from the nickname Liver, possibly a person similar to the liver of an animal ... Russian surnames
Large gland in animals and humans; participates in the processes of digestion, metabolism, blood circulation; ensures consistency internal environment body. In vertebrates and humans, liver cells synthesize bile. Happens in the liver... Big Encyclopedic Dictionary
Of all the organs of the human body, the liver is the largest gland and is second in size only to the skin, being the largest internal organ. The liver is formed in the embryo in the fourth week of pregnancy. During fetal development, the liver is divided into two parts called the right and left lobes. At the end intrauterine development right lobe the liver will be six times larger than the left. By the time the baby is born, the liver weighs about 5 percent total weight his body. A baby's liver grows and weighs three to four pounds (3 to 4 kg) in an adult. If you feel the lower right corner under chest, you will find a dense mass that, when tapped, makes a dull sound. This is your liver. Healthy liver has the consistency of a sponge. In a child with liver disease, the liver is often denser.
The liver is located under the diaphragm and ribs, it extends along the upper edge of the stomach to the left side of the body. Under the right edge of the liver are the green gallbladder and its ducts. The blood supply system of the liver is unique: through the large blood vessel, called the portal vein, blood comes from both the heart and the digestive tract. Each of the two large shares consists of smaller compartments called lobules. Typically, the liver has 50,000 to 100,000 lobules, consisting of a vein surrounded by tiny liver cells called hepatocytes. These cells cleanse the blood, remove waste, toxins and poisons, and store nutrients for use by the body when needed. The liver has a variety of functions: it converts sugar (glucose) into glycogen and stores it until the body needs it.
The liver also stores vitamins, minerals and iron until they are needed. Liver cells produce proteins and lipids, or fats, which include triglycerides, cholesterol and lipoproteins. The liver produces bile acids that break down edible fats. Bile acids allow the body to absorb fat soluble vitamins A, D and E. The liver removes from the blood chemicals, alcohol, toxins and drugs and sends them either as urea to the kidneys, which excrete them from the body in the form of urine, or to gastrointestinal tract, from where they are excreted in the form of feces.
When a person consumes food, nutrients pass through the throat into the stomach and then into the intestines. In these organs, food is broken down into small particles, thanks to enzymes produced by the pancreas, which are absorbed into the blood. Most of these fine particles passes from the intestines to the liver, which filters food and turns it into nutrients that the blood delivers to the cells that need them. The liver stores these nutrients, releasing them throughout the day when the body needs them. Proteins, fats, enzymes and others chemical compounds, which the liver synthesizes from nutrients, determine human health
The liver produces proteins necessary for blood clotting. If the liver is unable to produce these substances, death may occur due to blood loss. The liver also produces bilirubin, a red-yellow pigment formed when hemoglobin breaks down in dying red blood cells. The blood carries it to the liver, where it mixes with bile, and then enters the duodenum for excretion from the body. If the liver is damaged and is unable to remove reddish-yellow bilirubin from the body, jaundice occurs - the sclera of the eyes and skin acquire a yellowish tint. The liver produces the blood protein albumin, as well as cholesterol, which is necessary for the formation of outer cell membranes. When liver cells are damaged and cannot perform these functions, they release certain enzymes into the blood. To determine liver damage or disease, doctors test the presence of all these enzymes in the blood, as well as other liver-related substances. The liver is a very complex organ, so it is susceptible to many negative factors, including excess alcohol or drugs, infections such as viral hepatitis, cancer and other metabolic disorders. However, at the same time, the liver is a resilient organ, since it is capable of recovering from damage or inflammatory process; In addition, the liver contains reserves of nutrients that it can resort to when damaged. When the liver is infected with the hepatitis virus, its cells are damaged or destroyed. The liver can survive this type of damage due to its ability to regenerate and compensate for the damage caused. This stage of the disease is called compensated liver disease because the liver is able to continue performing all its functions. When the liver begins to succumb to disease, it can no longer regenerate its tissues, and the growth of scar tissue impairs its ability to filter and store nutrients. Such final stage The disease is called decompensated because the liver cannot compensate for the damage caused.
How can we help the liver easily bear the burden of our carelessness?
This is what the famous herbalist, Doctor of Medical Sciences, professor, head of the herbal medicine course at the department said about this family medicine MMA im. Sechenova Sergey Nikolaevich Turishchev:
- There are many fruits and medicinal plants, which contain active plant components that help a person protect the liver from diseases. Such properties are possessed, for example, by rosehip, mint, oregano, St. John's wort, chamomile, immortelle, corn silk, celandine, calendula, birch buds, milk thistle, oats, many vitamin preparations...
Celandine. IN folk medicine A decoction of celandine herb with flowers and roots in small doses is used for cholelithiasis, jaundice and other liver diseases.
It is known to increase bile secretion.
Calendula promotes the secretion of bile. In folk medicine it is often used as choleretic agent for liver diseases.
- In pharmacies today there are many “targeted” herbal infusions, which promote the secretion of bile, cleanse the bile ducts, and remove small stones. Medicinal plants are good because they are close in structure to the components of the human body. They act gently and are absolutely harmless, since man himself, albeit a unique one, is a biosystem. Official medicine today he no longer denies healing effect natural biologically active compounds. Moreover, it emphasizes not only their advantages, but often their advantages. Active substances Plants are not only able to cleanse the liver of toxins, which means protecting its cells from destruction, but also help restore already damaged liver cells.
Based on practical experience, I can say: natural remedies good for treatment chronic diseases liver. As you know, the percentage is now growing viral pathologies liver (hepatitis, cirrhosis, jaundice). And in case of high load on this organ, herbs will act as hepatoprotectors (literally, liver protectors).
Without much difficulty, you can help your liver through gentle nutrition.
In this sense, according to experts, boiled meat and fish, dairy products, oatmeal. And even more so - decoctions of natural oats. The same thing they feed horses. Cranberries are good at removing toxins and saving the liver from medicinal “violence.” lemon drinks. After all, all nutrients absorbed into the blood from the digestive tract pass through the liver and are processed there. At the same time, some of the fats are converted into carbohydrates, so the liver, figuratively speaking, is the largest glycogen depot in the body. It also synthesizes blood plasma proteins.
The diet will help normalize impaired liver and biliary tract function
Recommended products and dishes.
Egg - white omelet (without yolk) no more than 2 times a week.
Bread and bakery products- gray, rough bread. The cookies are not good.
Milk and dairy products: low-fat cottage cheese, one-day yogurt, low-fat kefir.
Fats: butter, sunflower in ready-made dishes.
Meat and fish dishes: low-fat varieties meat, boiled chicken. Lean fish(cod, navaga, pike) - boiled.
Soups - with vegetable broth or milk (with water). Cereals - buckwheat, oatmeal, pasta. Fruit soups.
Fruits, berries, sweets - ripe varieties of fruits and berries, raw and boiled, lemon with sugar, watermelons, soy chocolate, sugar.
Drinks, juices - rosehip decoction, various juices (with water), tea with milk, tea with lemon, dried fruit compotes.
Vegetables and greens - cabbage, potatoes, carrots, beets raw and boiled, onions are added after boiling.
Undesirable: mushrooms, beans, peas, peppers, sorrel, spinach, fried foods, egg yolks, canned food, alcohol, beer, sparkling water.
The protein content in this diet is 100-200 g, fat - 120-130 g, carbohydrates - 350-400 g. Calorie content - 3500 kcal, free liquid up to 1.5 l, table salt - up to 12 g.
This diet is good because it is balanced: it contains a normal amount of proteins and limits fats (especially lamb, goose, internal fat). The range of products that promote fermentation has been reduced. The amount of vegetables and fruits has been increased.
It is better to eat 4-5 times a day.
Don't climb the wall
Paradoxically, even a person’s behavior and character depend on the condition of the liver. Unconscious anxiety, irritability, and sleep disturbances can also be signs of liver system overload. Lose your temper - typical manifestation irritated liver. Even the ancients noticed this: harmful and vindictive choleric people were called gall people; closed, sad and painful melancholic people - people with black bile. And nowadays there are a lot of people walking around apt expressions, tracing the connection between the liver, health and character of a person: a bilious person, sits in the liver.
So if you help your protector - the liver, it will help you enjoy life more often.
BY THE WAY
In folk medicine, celandine is used as a remedy that inhibits the growth of certain malignant tumors. But we must remember that celandine is a poisonous plant, so it must be used internally with extreme caution. If poisoned, it can cause nausea, vomiting and even death.
Rosehip is ancient medicinal plant, medicinal properties which were known already in the 17th century. At that time, rose hips were highly valued and were given out for treatment with special permission only to noble and wealthy people. Its fruits contain so many vitamins that their variety exceeds all other plants known to medicine. That is why rosehip infusion is also good for the prevention of liver diseases. It increases the body's resistance to infectious diseases, in particular hepatitis. Promotes better secretion of bile. As is known, many are made from rose hips medicinal preparations for the treatment of hepatitis, cholecystitis.
The liver is the largest gland
The human body is amazing. So many different things happen in it complex processes, which in their totality allow the individual to exist - to have what they are accustomed to calling “full life”.
The main task of providing this falls on large organs in the body, including glands. They produce hormones that are responsible for many processes, without which the most significant events - physiologically and psychologically - for any individual (for example, digestion or childbirth) will simply become impossible.
At the same time, one’s own body remains largely a mystery to non-medics. So, not everyone will be able to say with accuracy what the largest human gland is. Meanwhile, without the compounds it produces, the absorption of many elements from food would not occur, the blood would not be purified, the removal of toxic substances would not occur to the proper extent, etc.
Hot organ
The above statements refer to the liver. It is considered not only the largest of the glands present in humans, but also the “hottest” organ. The constant temperature in it is about forty-two degrees. This is not surprising, because it is considered a real “industrial enterprise” of the body. It constantly produces lipids, bile, bilirubin, replenishes the supply of a number of vitamins and other nutrients, as well as hormones and enzymes, with the participation of which food is broken down into duodenum into component parts.
In general, the list of those chemical compounds in the production of which the above-mentioned largest human gland is somehow involved would be very extensive. However, this organ of considerable size (in an adult it weighs about one and a half to two kilograms) is also involved in many other processes that constantly occur in the body of every inhabitant of the planet.
Liver in critical situation
Thus, the liver neutralizes substances that are foreign and unsafe for humans (including poisons, allergens, etc.). Here they are transformed into more harmless compounds, which are then removed natural ways. Also using of this body excess of various hormones, vitamins, mediators and intermediates is removed harmful products metabolism (for example, ethanol, ammonia, acetone and others).
However, many people have an idea about these liver functions. However, not everyone realizes that it also serves as a kind of “blood reservoir”. A fairly large volume of this life-giving fluid is stored here. It is thrown into the vascular bed in case of injuries and other situations in which significant blood loss occurs.
Caring for your liver
With all those countless tasks (and not all of them are listed just above) that the liver has to cope with, it is, of course, very vulnerable to additional obstacles in their implementation, erected by the person himself. Is it worth mentioning in this regard the repeated “libations” that many of the planet’s inhabitants are addicted to, as well as other unsafe habits (for example, smoking), which supply the body with such decent volumes of toxins that the body’s main filter is not always able to cope.
In addition, many people are very indiscriminate in terms of diet, and in this regard, the liver encounters an excessive amount of fats and other difficult-to-digest compounds. This has a strong impact on negative side on liver functionality. However, she has the ability to regenerate, but sometimes even this is of little help.
Those who strive to join the ranks of centenarians who live out their centuries in perfect health should also take care of the liver. The recipe for this is simple - watch your diet and not overload the largest gland with harmful compounds.
