All about the liver: structure and function in the human body

from ancient times, the liver was considered one of the most important organs in human anatomy: the Egyptians called it the receptacle of the soul, the Assyrians identified it with the source of life and the most powerful libido, and the Chinese believed that it was here that negative emotions were stored. In those distant years, medical knowledge was far from modern, but even then, doctors intuitively noted the boundless influence of the liver on the state of the body. Subsequently, this theory received many scientific substantiations, so today no one doubts the importance of the gland in maintaining health.

A small educational program dedicated to the human liver will allow not only to thoroughly study the anatomy and physiology of this gland, but also, if possible, prevent the appearance of various diseases that somehow affect its functionality, and therefore the state of the body as a whole.

Liver structure: anatomy and blood supply to the gland

The liver is the largest gland in the body, the weight of which can reach one and a half kilograms. It is located directly in the abdominal cavity, tightly fitting to the right half of the diaphragm and partially passing to the left hypochondrium. Normally, the lower edge of the organ does not protrude beyond the edge of the costal arches, however, in the presence of pathology, it tends to increase in size, so the doctor has the opportunity for diagnostic purposes to probe the area where the human liver is located.

anatomy, liver

Depending on the location, two main surfaces of the organ are distinguished: diaphragmatic and visceral. The upper diaphragmatic surface determines the localization of the liver in human anatomy since it is tightly connected to the diaphragm through the ligaments formed during the transition of the peritoneum:

  • The falciform ligament, located in the sagittal region, divides the liver into right and left lobes.
  • The round ligament on the free edge of the crescent is the prototype of the overgrown umbilical vein.
  • The coronary ligament gives rise to two triangular plates, right and left. In anatomy, they are also referred to as the ligamentous apparatus.

The relief of the visceral surface facing downward is directly affected by the location of the liver in humans since the shape and size of the impressions completely copies the anatomy of the adjacent abdominal organs. From here, the ligaments depart to the duodenum, the lesser curvature of the stomach, and the right kidney. Also, grooves are located here, conventionally dividing the gland into 4 unequal lobes: right, left, caudate, and square.

The left longitudinal groove is represented by a round and venous ligament, the right one – by the edge of the gallbladder and the inferior vena cava. The transverse groove, which is called the gate, plays a much more significant role in the structure of the human liver than the topographic division of the gland into lobes. Here, the most important tubular systems of the organ are crossed – the incoming nerve fibers, the portal vein, and the own hepatic artery with the outgoing lymphatic vessels and the common hepatic duct.

Outside, the liver is covered with its own fibrous membrane, which is protected from three sides by the peritoneum. At the gate, the membrane penetrates into the parenchyma and forms connective tissue septa, dividing the organ into many structural units, lobules. Each lobule contains blood capillaries, bile ducts, and several layers of hepatic cells – hepatocytes that surround the central vein. The complex of structural units adjacent to each other is combined into liver segments, from which each anatomical lobe of the organ is composed.

liver, liver vessels

“Miraculous network” or a little about the blood circulation in the liver

Both venous and arterial blood can circulate in the liver parenchyma at the same time. A single capillary network, covering each lobule, unites numerous interlobular arteries and veins of the same name emanating from the hepatic artery and portal vein, respectively. From the capillaries, blood is collected in the central veins, which, when combined, form several more massive hepatic veins.

This type of blood circulation, which has received the unspoken name of the “miraculous network”, is explained by the complex interaction of two venous systems:

  • the portal system, flowing from the portal vein, brings blood to the liver from the abdominal organs;
  • The caval system, on the contrary, carries blood from the liver into the inferior vena cava.

The two venous complexes are united by the arterial system of the hepatic artery and the capillary network. Thanks to such complex, stable biochemistry of the liver is maintained, as well as the body as a whole.

liver

What functions does the liver perform in the human body?

The complex structure of the human liver in anatomy fully justifies the multifunctionality of the gland. Despite the fact that anatomically it refers to the digestive system, its effect on health is much wider. The human liver performs functions that in one way or another affect almost all processes occurring in the body:

  1. Detoxification. Thanks to the well-coordinated work of the hepatic lobules, the body is cleansed of harmful substances coming from the outside or formed in the digestive tract. The detoxification function of the liver consists in the breakdown of various toxins and their subsequent elimination, due to which the rest of the organs receive purified, absolutely harmless blood. Violation of this process can lead to damage to various systems of the body, but first of all, brain cells will be affected.
  2. Metabolism. Along with the antitoxic function of the liver, metabolism is the main process, which, in principle, is impossible without the participation of hepatocytes. The maintenance of an adequate metabolism directly depends on the proper functioning of the liver, because it is here that the key processes of the breakdown of protein molecules into amino acids, the formation of glycogen from excess glucose, the metabolism of hormones and vitamins, and lipid metabolism take place.
  3. Homeostasis. Hepatocytes maintain a constant blood biochemical composition since they regulate the synthesis of various metabolites and the excretion of “unnecessary” plasma components. Violation of the homeostatic function of the liver leads to a sharp change in the corresponding blood tests and, as a result, an imbalance in the internal environment of the body.
  4. Bile synthesis. In the hepatic lobules, bile is synthesized, which includes cholesterol, bile acids, and the corresponding pigments. The bile-forming function of the liver helps regulate digestion processes, including the breakdown of lipids and the absorption of vitamins.
  5. The accumulation of nutrients. The depositing function of the liver consists of the accumulation of nutrients, vitamins, hormones, and minerals, including iron, until the moment when their intake for some reason is insufficient. Such a “strategic reserve” guarantees an adequate response of the body to a temporary restriction of nutrition or dysfunction of the digestive tract.

Thus, the most important functions of the liver in an adult ensure the well-coordinated work of various organs and systems, the constancy of the internal environment of the body, its safety in the presence of foreign substances, and an energy reserve in case of a sharp restriction of nutrients.

ailments, liver, liver disease

What does liver dysfunction lead to?

The slightest deviation in the work of the gland in one way or another affects the state of health, causing pathologies of varying severity. Homeostasis is impaired, the process of digestion and breakdown of nutrients suffers, the body is at risk when even small doses of toxic or foreign substances are ingested. Moreover, the aggravation of the situation is fraught with irreparable consequences not only for the functions of the liver but also for other organs and systems of the patient. Therefore, it is extremely important to notice the appearance of problems at the initial stages – so there will be much more time and opportunities for adequate treatment.

The following symptoms are considered to be alarming “bells” indicating the appearance of pathologies:

  • yellowing of the whites of the eyes and skin;
  • pain in the right hypochondrium;
  • pale stool;
  • bloating;
  • itching of the skin, which becomes more noticeable at night;
  • increased urination, sometimes the appearance of orange pigments in the urine;
  • redness of the palms.

By itself, the liver cannot hurt, since there are no pain receptors in its parenchyma. Unpleasant sensations arise when it increases in size, when the gland begins to press on the walls of the surrounding shell – because of this, tangible discomfort appears. Therefore, with the slightest spasms or cramps, you should consult a gastroenterologist as soon as possible, so as not to aggravate the course of the disease. Knowing how a person’s liver hurts, evaluating the clinical picture and history, he will be able to prescribe qualified treatment in order to stop symptoms and reduce the risk of complications.

Factors provoking liver disease

What is good for the human liver, and what can be not only harmful but also dangerous? A list of the main risk factors, against the background of which liver diseases often occur, will help to avoid serious problems.

harm to alcohol, liver

1. Alcohol

The rating of liver-destroying foods is traditionally crowned with alcohol and its derivatives. Once in the digestive tract, ethanol is metabolized mainly by hepatocytes, which, under the influence of high doses, simply cannot cope with the load. Damage to liver cells leads to the accumulation of lipids and, as a result, fatty hepatosis. Against the background of such a condition, inflammation and/or excessive formation of connective tissue may occur, which, in turn, will sooner or later lead to cirrhosis.

With alcohol damage, liver function in the human body is noticeably inhibited. The patient may complain of weakness, tachycardia, decreased vitality, which is characteristic of withdrawal symptoms. As you recover, the intensity of the discomfort will decrease, but repeated use of alcohol-containing substances can worsen the condition.

2. Improper nutrition

What foods does the human liver dislike? Their list is not that wide:

  • various fast food and convenience foods;
  • confectionery;
  • sweet carbonated drinks;
  • coffee, strong tea;
  • meat products, including fatty broths;
  • canned and pickled dishes;
  • hot seasonings and spices;
  • everything fatty, fried, and smoked.
fast food, liver damage

Against the background of the use of harmful products, fatty deposits accumulate in the liver lobules, which reduce the functionality of the organ and lead to its degeneration. The expanding connective tissue displaces normally functioning hepatocytes, against the background of which non-alcoholic fatty disease occurs.

3. Violation of the rules for taking medications

Uncontrolled treatment with pharmaceuticals in one way or another affects the condition of the liver. The heavy load associated with the detoxification of the body in case of an overdose causes damage to cell membranes and, as a result, the destruction of hepatocytes. A similar biological effect is caused by poisons and toxins entering the body from the outside. Therefore, you should not prescribe medication yourself, and even more so take them not according to the instructions. So you can not only not get rid of the disease, but also add new health problems.

4. Viral diseases

Viral diseases that have a direct effect on the liver, depending on the type of microorganism, can cause serious deviations and even death. The most common are various hepatitis leading to liver tissue necrosis.

To minimize the likelihood of contracting hepatitis, you should exclude possible ways of transmission of the virus: lead a healthy lifestyle, exclude unprotected sex with casual partners, observe the rules of hygiene and sanitation.

proper nutrition, healthy liver

Prevention of liver disease

You don’t have to drink synthetic vitamins or other medications to improve liver health. The main thing is to correctly formulate a daily diet, which will not only have a positive effect on hepatocytes but also strengthen the immune system.

What is good for the liver? In the list of products, the leading positions are occupied by plant foods:

  • apples
  • avocado
  • cherry and sweet cherry
  • grapefruit
  • plum
  • banana
  • apricot
  • olive oil
  • pumpkin
  • kelp
  • lemons

A banal change in diet will allow you to avoid serious liver problems, and therefore improve the general condition of the body. In order not to waste time, effort and money on overcoming the ailment, take care of the prevention of liver diseases in advance – this will allow you to maintain health for many years.