Liver

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liver gland is one to lobulare annexed todigesting apparatus.

Human anatomy

Advanced sight of the liver

Inferior sight of the liver

The liver is localized inipocondrio right, with a propaggine that is pushed towards left, until covering the ipogastrica area and a part of the left ipocondrio. It has a red-tawny color and a weight of 1.500 g approximately.
It has a ovoidale shape and it introduces three faces (advanced, inferior, posterior) and one circumference.
make advanced it is to contact with diaphragm.
make inferior, beyond that low, it behind watches also and a po' on the left, it is crossed to the center from two furrows sagittali and from one cross-sectional, much to form one H, dividend the surface in four lobes. I furrow cross-sectional takes the name of ilo, from they pass here is gone blood (hepatic artery, vein door, vein inferior quarry) and the nerves and exit are gone linfati to us and hepatic culvert.
The four lobes are distinguished in:

• skillful lobe
• left lobe
• square lobe
• caudato lobe of Spigelio.

In the inferior surface of these lobes, they are present of the "prints, caused from the organs on which the liver rests:

• on the skillful lobe, the colica print, the duodenal print and the renal print
• on the left lobe, the gastric print and the splenica print (due to milza).

make posterior leggermente incurvata, in how much it collects in the concavity vertebral column.
circumference it corresponds to the acute margin that separates to the advanced face from the inferior and the posterior face from the inferior.
The liver is maintained in situated from legamenti that connect it to the near organs:

• falciforme legamento, similar to one scythe, it is stiff from the advanced face to diaphragm
• small omento, attacked to the ilo of the liver it catches up the small curving of the stomach
• coronary legamento, it is decided cross-sectionally and it connects the posterior face to the posterior wall ofabdomen; the extremities of this legamento are said triangular legamenti
• dorsal legamento, in vertical, it connects the center of the posterior face to the posterior wall of the abdomen.

Structure

The liver is wrapped in one woven cap of connecting, in correspondence of the ilo, it is penetrated in the hepatic woven one decomposing it in many lobuli of pyramidal shape, large 1-2 cm.
Every lobulo it is crossed from one vein to centrolobulare, around to this the hepatic cells are organized, ordered in lamelle that from the irraggiano periphery to the center. Between lamelle the capillaries that converges anch' they towards the vein to centrolobulare.
Also capillary the biliary ones converge towards the vein, but they are not never interlaced with capillary the blood ones; they are assigns you to the transport of the bile produced from the hepatic cells. The blood meets from the outside towards the vein, the bile travels in contrary direction flows from the center towards the surrounding spaces to the lobulo hepatic (you space perilobulari or of Kiernan).
The hepatic cells are poligonali. In the wall of capillary the blood ones stellate cells are found, cells of Kupffer.

Blood circulation

From the ilo, it penetrates vein door, that door the nourishing you become lean yourself fromintestine, andhepatic artery. These are subdivided in are gone more and more small, they enter between lobulo and lobulo (interlobulari nets), therefore perilobulari nets are subdivided ulteriorly () and enter in the lobuli to constitute of the driven in net of capillary. The blood then meets in the vein to centrolobulare and from it gathers here in vein inferior quarry.

Production of the bile

Capillary the biliary intralobulari collect bile supplied from the hepatic cells, irraggiano from the center of the lobulo towards the periphery; here they are collected in perilobulari biliary culverts, then in interloburari culverts, in order to meet in hepatic culvert, that it exits from the liver through the ilo.

Escretore apparatus

The hepatic culvert feeds cistico culvert of gall bladder with which form coledoco.
The coledoco it catches up duodenum, opening itself inampoule of Vater, that it collects also pancreatico culvert of Wirsung.

Function

The function of the liver is tied to internal digestion, with the production of the bile, that it comes stored in the poured gall bladder and from lì in the duodenum in the moment of the digestion.
But this is one of the functions of the liver and not even the more important. In the liver they come convogliati all the products of the digestion. The blood that arrives from the intestine and from milza it is collected in principle in three log main: advanced mesenterica vein, inferior mesenterica vein and lienale vein or splenica. These veins gather to form the vein door, that it enters in the liver from the inferior face.
It arrives you to the liver endure those transformations necessary chemistries so that they can be used from the organism.
The liver is in a position to working like filter of the ingested products, concurring also to detoxicate the body from eventual toxic substances, that I remove through a chemical procedure.
In the liver, the reduced substances to elementary units, they come newly cemented, reconstructing complex molecules, much similar to those that the digestion had destroyed. The reconstruction made from the liver conforms molecules in a structure that confà to those of which the human body is constituted. The esplica liver also the function of warehouse of reservoir of "finished products", which the organism it can approach in the necessity moments. In the hepatic cells they are accumulateed proteins and fat people, but above all glycogen; in the liver they come also conserved vitamins, indispensable for the reactions chemistries that maintain the organism while still alive. During the fetal life the liver is determining inemopoiesi (the production of red globules and white men, to which it participates with to milza and to bony marrow; after the birth this activity is carried out solo from the bony marrow. The liver constructs maggiora the part of proteins of the blood, comprised those indispensable ones for the coagulation, like prothrombin (that it obtains through K vitamin), Ac-globulina or factor V and convertina or factor WAYS. Other produced proteins of the blood from the liver are apoferritina andipertensinogeno. The apoferritina has the task to transport iron that it will formemoglobina; it acts also like agent whom it lowers arterial pressure. The ipertensinogeno, of for if inactive, when it comes in contact with renin it is transformed in ipertensina, that it provokes the constrizione of the arteriole, increasing pressure of the blood.
The liver controls also hormones and it acts on they in various ways:

• of modification the chemical structure rendering them inatti to you
• it arranges them with substances that of it block the action and it eliminates them through the bile
• it joins them with vettrici proteins that yield them at the moment and in the opportune point.

Between the more important hormones to consider sure there e'insulin, that it comes fixed in the hepatic cells and rilasciata in the necessity moments.
The liver constitutes a warehouse for the blood, that the organ rilascia not hardly ve of is need.

Formation of the glycogen

digestion andinternal absorption they make to reach the liver simple units, i monosaccaridi (fructose, galattosio, glucose, etc.). All the monosaccaridi, they come transforms to you in glucose, because it is the solo that can concatenato to form the glycogen. The glucose is one of the constituent essential things of the blood and its concentration (glicemia) it must be maintained on constant values. If this comes down or increases, the organism goes encounter to serious disturbs, that they can carry also the dead women.
The main organ that res-establish I balance it is the liver. If the glucose in the blood diminishes it is from here that the glucose enters in circle in the blood; if instead the glucose it increases is still the liver that takes part, condensing the glucose and storing it under shape of glicogene.
The conversion glucose-glicogene is the means that allow storing and I use it of the energy assimilated through the alimony.

When all the monosaccaridi have been transform to you in glucose, policondensazione begins the process of conversion in glycogen ().
The first transformation of the glucose is represented from the fosforilazione: one molecule of phosphate it comes added to that one of glucose for through of one enzyme and ofadenosintrifosforico acid (ATP). The ATP introduces in its molecule three units of phosphates and in a position to rilasciarne one to an other compound, under the action of an enzyme.
The fosforilazione of the glycogen is accompanied also to physical process: the captazione to endocellulare of the glucose. The glucose is in a position to entering in cells, but once that it is legacy to the phosphate, it cannot be more diffused, remaining localized in the cell. Cosi can supply one immediate energetic substance or to maintain stored it like glycogen.
The glucose, with the added one of the phosphate, it has been transformed therefore in glucose-6-phosphate, this represents the shape base that can endure ulterior various transformations. The glucose-6-phosphate can be used endured, demolishing it and generating energy, or it can be stored like glycogen, but ulterior transformation must endure one: the phosphate must migrare from carbon 6 to carbon 1. The migration comes put into effect from an enzyme that will form the glucose-1-phosphate.
The glucose-1-phosphate, always for means of enzymes, they come joined between they and during the reaction the phosphate molecules are detached. The glycogen chain has been formed.

The glycogen can to this point to be used like substance of reservoir: the large molecule can be attacked to the periphery from an enzyme, detaching joined of glucose that subiranno a fosforilazione process, obtaining a new on line glucose-6-phosphate energetic.
This substance is not found alone in the liver, but in all the other organs. In the liver the relative amount is sure greater, but the greater absolute amount is present in musculature, where the glycogen comes consumed: the muscular contraction happens throughoxidation of the glucose gained from the glycogen.
When the reservoir of glycogen of muscles diminishes, the liver demolishes glycogen ivi content, the glucose arrives to muscles through blood and here it comes newly transformed in glycogen. The liver, not having an energetic fort dispendio, the energy in accumulated it without risentirne can rilasciare. Moreover its "chemical laboratory" is the much most efficient one than that one of muscles and is in a position to synthetizing the glucose from other sources.

Activity on the fat people

During the internal absorption, i trigliceridi scissi come in glycerin and fat acids (hydrolysis). This division is necessary every time that these substances must cross a cellular membrane. When they exit from the cell, one often risintesi of the trigliceridi is had nearly immediate.
The trigliceridi they are insoluble in the organic liquids and come therefore transports to you in shape of small spheres: the chilomicroni. Only 40% of the fat people arrive to the liver through vein door, the rest enters directly in it arranges linfatico and from here to blood circulation.
The trigliceridi they go in three directions:

• the adipose cells scattered in all the body
• the cells of the woven ones that they complete a heavy job (es. woven muscular)
• the liver.

It arrives you to the adipose cells, they exceed the barrier of the cellular membrane, and they come stores to you in the same cell, ready for being it uses you in the moment of the need. In woven the subordinates to job, the trigliceridi scissi come and burn to you. Those that arrive to the liver, they join to the chilomicroni arrives to you from the intestine directly. These fat people endure two various destinies: they can be burns to you from the cells of the liver for theirs directly needs or come immessi in the blood circle newly.
In order to allow the transport of the trigliceridi in the blood, il のfegato のattua 国連のnuovo のmeccanismo 、 anch' comprised it between the functions of the liver: the connection trigliceride-albumin. These complexes could be burn to you from "working" cells or are become lean from the adipose cells that will transform them in placed you of fat person.

Activity on proteins

The liver synthetizes from amino acids of the alimony proteins that they serve for the lipid transport, hormones and other substances.
The proteins will be used also in order to create oncotica pressure that it influences in the exchange of liquids between blood and woven.

Detoxification

The liver participates actively to the detoxification of the organism, eliminating injurious slags and products.

Inner pathology

Relations with the digesting apparatus

The relationships between liver and digesting apparatus they are many straits.

As consequence is had the influences exercise dal liver to you in disease occasions sull'intestine and the pathology of the intestine that will interest the liver.
The first influence that a epatopatia exercises on the digesting channel is the passing of the appetite.
One biliary stasis (lacked deposit bile in the intestine) it compromises in sensitive way the absorption of the alimentary substances, to which they will be able to follow coagulation defects (for insufficiency of K vitamin) or defects of ossification (for insufficiency of D vitamin and of soccer).
atrophic gastritis with ipoacidità it is found frequently in the epatopatie. To cirrosi hepatic it is associated sometimes alsogastric ulcera or duodenal.

The diseases of the intestine provoke one bad digestion of the alimony. The absorption becomes imperfect and limits the functionality of the liver, riversando on this one great amount of toxic and bacterial substances. Also one simple diarrhoea, especially in the children, it provokes I accumulate of fat person in the liver, meaningful symptom of the job overload to which the liver he is subordinate.

Relations with the blood

In exceptional cases, the activity of emopoiesi of the liver comes resumption, like as an example in the destruction of the bony marrow or inpernicious anemia.
In the course of hepatic diseases, especially if of long duration, it is had nearly alwaysanemia. To they time, anemias not of hepatic origin, they provoke lesions to the liver, caused of the low contribution of oxygen to the same organ.
If, because of pathologies of the liver, the ematiche proteins diminish, a quota the liquid part of the blood exits from i it is gone, accumulateing itself in the woven ones (edema).

Relations with kidneys

Kidneys and liver have one strongly predominanza in the excretion processes and detoxification. The kidneys pre-eminent in the excretion of the refusal products, the liver in the detoxification of the injurious substances.
In necessity case they are compensated vicendevolmente, even if within limits not too much wide.
In the course of renal diseases, the problems to the liver are somewhat modest. If the disease is to cargo of the liver, the kidney of risente deeply.
In the case of icterus, determined from stasis of bile in the liver, it is had nefrosi biliary, caused from the attempt of the kidney to compensate the insufficient hepatic activity. The block of the biliary flow, it prevents the drainage of pigments deriving from the emoglobine of destroyed red globules, that it happens through the intestine with I made. The pigments are accumulateed in the blood and the kidney tries to eliminate them with urines. When the kidney is not more in a position to eliminating them, they are accumulateed in the cells and the tubuli renal.
Also nefrosi glomerulo-tubular it derives from diseases of the liver, that cause lesions to groups of cells of the kidney and the albumin appearance in urines. The causes are from searching themselves in the presence of toxic substances in the blood that the liver has not been in a position to neutralizing.
When the phenomena become imposing, it is arrived to nefrosi acute, that door to the most serious consequences.

Relations with the endocrine system

The function of the liver on hormones is much efficient and adaptable one, but it is also remarkablly complex, much to be disturbed from problems in its operation.
In some endocrine diseases the interest of the liver is found, like with thyrotoxicosis, mellito diabetes and morbo of Addison.
In the diabetes, the liver ingrossa in more of the half of the patient, generally without to influence on its function. Also in morbo of Addison and the thyrotoxicosis the liver ingrossa, reducing the production and the activity of some its enzymes. However, the activity of the liver comes insufficient compromised from diseases of the endocrine glands.
Very various hepatic lesion is the case of one, that it can carry to hormonal imbalances, also remarkable.
The production of estrogens, feminine hormones, but produced in minimal amount also in the males, it comes regulated from the liver, that of it it destroys the amount in excess. If the liver is leso, it does not carry out its task and, in the males, it can carry to atrophy of i testicoli, with consequent sterility, fall of the hairs and, to times, increase of the volume of mammelle. In the women they appear disturbs menstrual, that they can carry to sterility.
They can be had also disturbs to level of hormones produced from surrene, like the reduction in the production of cortisone. The cortisone comes emitted through the stimulus ofACTH produced fromipofisi, production that happens when the cortisone comes down under one sure threshold. If the liver destroys the cortisone in inferior amounts, the ACTH production diminishes in consequence, reducing the pressure on the surrene in order to produce the cortisone. In the short term this is a good, in how much it reduces the cortisone in circle, but, in the long term, door to one inability of the gland to produrne, in forced how much to an excessive rest, that of it it has reduced the abilities. This involves that the sick one of liver will be more fragile regarding the infectious diseases, to the traumi, etc.

An other aspect of the ormonica alteration is the water retention, that cause swellings up to the ankles and I accumulate it of water in the abdominal cavity (ascites).

Relations with other organs

The liver stores the blood until ve of it is not need. The blood amount that circulates, condition the activity of heart.
In the case of problems cardiaci, the heart is not in a position to pompare all the venoso blood, that ristagnerà in the liver; if the situation becomes serious, the liver ingrossa, the cap that wraps it, stretching itself, it provokes to strong pains and a sense of gravity in the region.
In presence of cirrosi hepatic, the blood does not flow down from the vein door well towards the liver, it will try therefore other ways of outlet, provoking hemorrhoidses, vary us toesophagus and to the inferior limbs.

it arranges nervous insufficient it is interested from a hepatic problem, at least finche the situation does not become therefore serious to provoke a poisoning of the organism. In this case the nervous functions come blocked, reaching coma.

skeletal apparatus risente of problems to the liver after long periods, because of the lacked absorption D vitamin and of soccer. The boneses become more fragile more and therefore exposed to fractures.

You see also

Transplant of liver

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