Tag: functions of the liver

Glycogenesis is the conversion and storage of extra amount of glucose into glycogen from the digested food. In human body glycogen is strored in liver and muscles.

The main centre of carbohydrate metabolism is liver. Following steps are related with carbohydrate metabolism-
(i) Glycogenesis- The conversion and storage of extra amount of glucose into glycogen. The main stored food in the liver is glycogen.
(ii) Glycogenolysis- The conversion of glycogen into glucose back when glucose level in blood falls down is called glycogenolysis.
(iii) Gluconeogenesis- At the time of need, liver converts non carbohydrate compounds (e.g., amino acids, fatty acids) into glucose. This conversion is called as gluconeogenesis. This is the neo-formative process of glucose. 

Deamination and urea formation is a major function of liver. Deamination of amino acids is mainly done by liver (separation of amino group of amino acid and its conversion to ammonia). Preparation of urea from the amino acids is done by the liver. Liver converts ammonia (obtained from deamination) into urea through ornithine cycle. So, after the damage or spoilage of liver, the ammonia level in the animal body is increased and the animal dies.

Stool that is pale or whitish grey colour may be caused by insufficient bile output. Bile salts from the liver give stool its brownish color. If there is decreased bile output, stool is much lighter in color. Thus whitish grey colour stool is due to malfunctioning of liver.

1.  Deamination is the process by which amino acids are broken down if there is an excess of protein intake. It is the removal of an amine group from a molecule in the presence of an enzyme called Deaminase. It takes place in the liver. This process allows the system to convert excess amino acids into usable resources such as hydrogen and carbon and also plays a vital role in removing nitrogen waste from the body. Hence deamination occurs in the Liver. 

Liver stores fats in a small amount. Hepatic cells plays an important part in fat metabolism. The storage of fats increases in the liver of alcohol addict persons. This is commonly called as fatty liver. The excess storage of fats decreases the activity of liver. The damage of liver due to alcohol intake is called as alcoholic liver cirrhosis.

Human alimentary canal or gastrointestinal tract associates wit salivary glands, liver, pancreas, small intestine etc. The adrenal glands are endocrine glands that produce a wide variety of hormones. They are found above the kidneys and consist of a number of different layers that directly influence the structure and function of the glands. It is not associated with alimentary canal. Thus, option B is correct. 

Jaundice is caused by a build-up of bilirubin in the blood and tissues of the body. Any condition that disrupts the movement of bilirubin from the blood to the liver and out of the body can cause jaundice. There are three types of jaundice, depending on what is affecting the movement of bilirubin out of the body. Pre-hepatic jaundice occurs when a condition or infection speeds up the breakdown of red blood cells. This causes bilirubin levels in the blood to increase, triggering jaundice. Intra-hepatic jaundice happens when a problem in the liver for example, damage due to infection or alcohol, disrupts the livers ability to process bilirubin. Post-hepatic jaundice is triggered when the bile duct system is damaged, inflamed or obstructed, which results in the gallbladder being unable to move bile into the digestive system.

Hepatocytes are metabolic superachievers in the body. They play critical roles in synthesizing molecules that are utilized elsewhere to support homeostasis, in converting molecules of one type to another and in regulating energy balances. Excess glucose entering the blood after a meal is rapidly taken up by the liver and sequestered as the large polymer, glycogen (a process called glycogenesis). Later, when blood concentrations of glucose begin to decline, the liver activates other pathways which lead to depolymerization of glycogen (glycogenolysis) and export of glucose back into the blood for transport to all other tissues. Excretion, digestion and histolysis are not the functions of liver. Thus, option D is correct.