Structure and function of liver with special reference to detoxification

               Structure and function of liver with special                                          reference to detoxification

·      What is liver?

ü The liver is the largest internal organ of body.  

ü The body’s second largest organ after the skin.

·      It has four lobes and is surrounded by a capsule of fibrous connective tissue called Glisson’s capsule.                         Location of liver in human body.

The liver is located in the upper right-hand portion of the abdominal cavity, beneath the diaphragm, and on top of the stomach, right kidney, and intestines.

·      Morphology of liver.

ü Shaped like a cone.

ü Liver is a dark reddish-brown organ.

ü Weighs about 3 pounds.

ü It doesn't pulsate.

ü it doesn't move much, only passively, and you don't ordinarily see it secreting anything.

Here is a diagram of liver.

STRUCTURE OF LIVER

The liver holds about one pint (13 percent) of the body's blood supply at any given moment. The liver consists of two main lobes, both of which are made up of thousands of lobules. These lobules are connected to small ducts that connect with larger ducts to ultimately form the hepatic duct. The hepatic duct transports the bile produced by the liver cells to the gallbladder and duodenum (the first part of the small intestine).

·      Over activity of liver.

 When considering a cleansing program. When the liver is over-stressed all other organs start to dysfunction. It is constantly working to break down not only the environmental and external toxins that invade our body though breathing and eating, but also those produced during normal metabolic processes in the body (internal toxins). Many common symptoms such as headaches, mental confusion, muscle pain, fatigue, poor coordination, nerve problems, skin irritations and emotional imbalances can be a result of over exposure to toxins. If liver function can be improved the entire body will benefit.

FUNCTIONS OF LIVER

The liver has a number of important functions, some of the main ones being:

1-Detoxification of potentially toxic chemicals from both inside and outside of the body including drugs, alcohol and toxins from intestinal microbes. Accomplished with antioxidant nutrients and enzymes such as glutathione. The liver detoxifies these harmful substances by a complex series of chemical reactions. The role of these various enzyme activities in the liver is to convert fat soluble toxins into water soluble substances that can be excreted in the urine or the bile depending on the particular characteristics of the end product.

1.   Storage of sugar as 'glycogen' and regulation of blood sugar levels.

2.  Production and storage of proteins as well as the regulation of many substances involved in protein metabolism.

3.  Production of bile which aids in the digestion of fats.

4.    Production of blood proteins, clotting factors and                    red blood cells (erythrocytes).

5.     Regulation of a number of hormones.

6.    Neutralization of 'free-radicals' by antioxidants.          free radicals are highly reactive oxygen molecules that can damage tissues.

    7.  Storage of vitamins, mainly iron, copper, B12, vitamins A, D, E and K

     8.  It plays an important role in digestion (breaking nutrients down)

    9.  Involved with assimilation (building up body tissues).

    10.  Red blood cells, which are responsible for carrying oxygen around the body, are recycled in the liver. 

DETOXIFICATION

Detoxification is the process of clearing toxins from the body or neutralizing or transforming them, and clearing excess mucus and congestion. Many of these toxins come from our diet, drug use, and environmental exposure, both acute and chronic.

Detoxification process:

 The liver is one of the four major organs that eliminate toxins from the body. The other three organs involved are the kidneys, intestinal tract and skin. The liver detoxifies harmful substances whether they come from internal sources such as burning sugars, fats, protein, or from external sources like medications, drugs, hormone enhancers, food additives, preservatives, food colorings, sweeteners, and flavor enhancers, chemicals used in agriculture, alcohols, volatile organic compounds, fumes, air pollution and many other factors. Many of the toxins that enter the body are fat soluble which means they dissolve only in fatty or oily solutions and not it water. They all must travel through the body and the first step in the detoxification process they will encounter is the liver. The liver has to convert fat soluble toxins into water soluble substances that can be excreted from the body.

 The liver plays several roles in detoxification: it filters the blood to remove large toxins, synthesizes and gets rid of bile full of cholesterol and other fat-soluble toxins, and the live enzymatically eliminates unwanted chemicals. The enzymatic process to dispose of toxins occurs in two phases: phase 1 (Oxidations) and phase 2 (Conjugation). Phase 1 neutralizes the toxin or changes the toxic chemical to form activated intermediates which will then be neutralized by phase 2 of the enzyme system. This pathway converts a toxic chemical into a less harmful chemical and is achieved by oxidation, reduction and hydrolysis reactions. During this process, free radicals are produced and if there are too many it can damage the liver cells. With the help of antioxidant, it reduces the damage caused by free radicals. One important antioxidant for neutralizing the free radicals produced in phase 1 is glutathione (GHS) is oxidized to glutathione disulfide (GSSG). This antioxidant is required for one of the key phase 2 processes. When so many free radicals are produced from phase 1, the glutathione stops producing oxidative stress or liver damage. The toxins are then transformed into activated intermediates; therefore the rate at which phase 1 produces activated intermediates must be balanced by the rate at which phase 2 finishes their processing. Phase 2 is called the conjugation pathway because the liver cells add another substance such as cysteine, glycine, or a sulphur molecule to a toxic chemical to make it less harmful. As a result it makes the toxin water-soluble so that it may then be excreted from the body via watery fluids such as bile or urine. 

 Ø Urea cycle : The metabolic pathways in the production of urea are termed as urea termed as urea cycle. Two ammonia and one carbon dioxide molecules are shunted into the to generate one molecule of urea.

One ammonia molecule combine with carbon dioxide and already available precursor from previous cycle ornithine to form citruline, subsequently another ammonia is combines to form arginine. The arginine is split by arginase. The arginine  is split by arginase to form urea and the precursor orthinine for next cycle.