Functions of the liver - class-XI

The liver doesn't secrete any enzyme. The liver only secretes bile that it produced by the byproducts of haemoglobin breakdown. With the presence of bile, lipase, an enzyme will be able to break down the fat into smaller units. 

Kupffer cells constitute 80-90% of the tissue macrophages present in the body. They are found in the lumen of the liver sinusoids. 

Kupffer cells are specialized macrophages located in the liver, lining the walls of sinusoids. Kupffer cells are a part of the mononuclear phagocytic system. The main function of kupffer cells is clearing any bacteria or foreign substances which are harmful to the body. Hence, Kupffer cells of the liver are the phagocytic cell.

During its lifecycle, the infective juvenile or rhabditiform larva of Ascaris migrates through the bloodstream to the heart and lungs. It undergoes its second and third molts inside the alveoli of the lungs before moving up the trachea.

A. The functional unit of liver is called hepatic lobules. 

•  The liver is digestive glands situated outside the digestive tract.
• The liver is the largest gland of the human body.
•  It weighs about 1.2 to 1.5 kg in an adult human, so option B is correct

The liver is the body's largest gland. An adult human liver weighs between 3.2 and 3.7 pounds. The right lobe of the liver is the largest and is six times larger than the left lobe.

Kupffer cells, also known as Browicz-Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system. Red blood cells are broken down by phagocytic action of Kupffer cells, where the hemoglobin molecule is split. The globin chains are re-utilized, while the iron-containing portion, heme, is further broken down into iron, which is re-utilized, and bilirubin, which is conjugated to glucuronic acid within hepatocytes and secreted into the bile.

In mammalian bodies, Kupffer cells are the most abundant tissue macrophages as they constitute 80-90% of them. Also known as Kupffer-Browicz cells or stellate macrophages; these specialized macrophages are specifically found in the liver.

• Each lobule in the liver is made up of millions of hepatic cells, which are the basic metabolic cells. 
• These lobules are held together by a fine, dense, irregular, fibroelastic connective tissue layer which extends from the fibrous capsule covering the entire liver known as Glisson's capsule.
•  Glisson's capsule forms a layer of connective tissue surrounding the liver and ensheathing the hepatic artery, portal vein, and bile ducts within the liver. Hence, Glisson's capsule is associated with the liver.

Liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity, just below the diaphragm and has two lobes. The hepatic lobules are the structural and functional units of liver containing hepatic cells arranged in the form of cords. Each lobule is covered by a thin connective tissue sheath called as the Glisson's capsule.

Kupffer cells, also known as Browicz-Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system. 

• In vertebrates, the gallbladder is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. 
• In humans, the pear-shaped gallbladder present on the right lobe of the liver that lies beneath the liver, although the structure and position of the gallbladder can vary significantly among animal species. Hence, Gallbladder is found in

Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids, that form part of the reticuloendothelial system.

Liver is the largest gland of human body. Liver sinusoids are lined by the endothelial cells mostly but a few macrophages cells are also present. These are called as Kupffer's cells (phagocytic cells).

The liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the right upper corner of the abdominal cavity, just below the diaphragm and has two lobes. The hepatic lobules are the structural and functional units of liver containing hepatic cells arranged in the form of cords. Hence, the liver is situated in the upper part of the abdomen on the right side.
So, the correct option is 'right side'.

The liver is the largest glandular organ in the body and performs multiple critical functions to keep the body pure of toxins and harmful substances. An average adult liver weighs about three pounds. Located in the upper-right portion of the abdominal cavity under the diaphragm and to the right of the stomach, the liver consists of four lobes. It receives about 1.5 quarts of blood every minute via the hepatic artery and portal vein. 

The hepatic artery and hepatic portal vein carry blood into the liver. The hepatic vein carries blood away from the liver toward the inferior vena cava.

The rabbit's liver is divided in left and right regions by a deep cleft with the right and left lobes further divided into anterior and posterior lobules. The left lobes are left lateral, left central and a spigelian lobe. The right lobes are right central and caudate lobe.

• The liver is an organ that is present on the right side of the stomach.
• Liver tissue is made up of lots of smaller units of liver cells called lobules. Many canals carrying blood and bile run between the liver cells. 
•  Reticular fibre is a type of fibre in connective tissue. It is composed of type III collagen secreted by reticular cells. Reticular fibres crosslink to form a fine meshwork(reticulin). 
• This network acts as a supporting mesh in soft tissue such as liver, bone marrow and the tissues and organs of the lymphatic system. Hence, the Liver is called the reticular gland because it contains reticular tissue.

In mammals liver has extensive power of regeneration. If a part of liver is surgically removed the cells of the remaining part undergo repeated division until the original volume of this vital organ restored 

The liver is the largest internal organ and the largest gland in the human body.

Cod and shark liver oils are rich in vitamins A and D (protective) and fats (constructive/energy-providing), making them both protective and constructive nutrients.

A. The ovaries are solid organs and are composed of connective tissue, the stroma. The stroma consists of an outer ovarian cortex and central ovarian medulla.

Glisson's capsule is the characteristic feature of 'mammals'.

The rabbit liver is situated in the epigastric region, between both costal arches, reaching the level of the right 7th and left 9th ribs. Rabit liver is divided into two right and left the region by deep cleft with right and left lobes. These lobes are further divided into the posterior and anterior region. It contains five lobes, as the right hepatic lobe, caudate and quadrate lobes are single, and the left hepatic one is separated in lateral and medial parts. Thus the correct answer is option C.

Heparin is an anticoagulant that prevent blood clotting by the release of specific proteins like tissue plasminogen activator and tissue factor pathway inhibitor, into the blood.

Sinusoids are characterized by a form of terminal blood channel consisting of a large, irregular anastomosing vessel having a lining of reticulo-endothelium and found in the liver, heart, spleen, pancreas, and the adrenal, parathyroid, carotid, and hemolymph glands.

The liver is the primary site for cholesterol biosynthesis in the human body.

The liver performs several roles in lipid metabolism. Cholesterol, triglycerides (fats) and lipoproteins are synthesized in the liver.

Deamination is the process of removal of amino acids like serine and threonine from molecules and the enzyme that catalyses the reaction is deaminases. In the human body, it takes place primarily in the liver however glutamate is also deaminated in the kidneys.

Kupffer cells are specialized macrophages located in the liver sinusoids that perform phagocytosis to remove debris and pathogens.

• Hormones are secreted by the endocrine glands which are specific in nature.
  
• Each hormone causes a response in a target organ or tissues.
• Once the function of the hormones is completed on their target organs or tissues they are destroyed. 
• They are destroyed by the liver or the tissues of the target organs. 
• The destroyed hormone is removed by the kidney. 
  
• So, the correct answer is 'Liver'.

Bile is produced in the liver and then it's concentrated in the gallbladder. From gallbladder, it goes through the cystic duct. Cystic duct joins the pancreatic duct to form the hepato-pancreatic duct. Pancreatic juice and bile juice together is secreted through a common hepatic duct into the duodenum. During secretion from the hepato-pancreatic duct, pancreatic juice is present too making bile juice diluted. 

The liver synthesizes most of the major plasma proteins involved in blood coagulation, notably prothrombin and fibrinogen. Other factors like thrombin are active enzymes converted in the blood rather than directly synthesized as active factors by the liver.

The liver breaks down hemoglobin from old red blood cells and excretes the resulting breakdown products, known as bile pigments (bilirubin and biliverdin), into the bile. Urea is produced in the liver but excreted primarily by the kidneys.

Glycogen is a branched polysaccharide of glucose molecules that serves as the primary short-term energy storage carbohydrate in animals, being abundantly synthesized and stored in liver and muscle cells.

Instead of accumulating inside the muscle cells, lactate produced by anaerobic fermentation is taken up by the liver. This initiates the Cori cycle. In the liver, gluconeogenesis occurs, which reverses both glycolysis and fermentation by converting lactate first into pyruvate, and finally back to glucose. The glucose is then supplied to the muscles through the bloodstream. If muscle activity has stopped, the glucose is used to replenish the supplies of glycogen through glycogenesis.

Liver is the largest gland in the body. It is a digestive gland present at the left half of the digestive system besides stomach. It synthesises bile, which emulsify (breaking into small droplets) fats and increase the surface area for the action of lipase enzyme.

The fat in the human diet is in the form of triglycerides. To use the fat as a source of energy for the body it needs to be broken down - a process referred to as fat metabolism.  This metabolism which takes place primarily in the liver gives out cholesterol and phospholipids. These are made available to the rest of the body along with lipoproteins and the rest are excreted out through bile. Thus, the correct answer is option D.

Once glucose is inside the liver, glucose is phosphorylated into glucose-6-phosphate, or G6P. G6P is further metabolized into triglycerides, fatty acids, glycogen or energy. Glycogen is the form in which the body stores glucose. The liver can only store about 100 g of glucose in the form of glycogen. 

The glucose stored in the liver serves as a buffer for blood glucose levels. Therefore, if the blood glucose levels start to get low because person has not consumed food for a period of time, the liver is able to release glucose into the bloodstream to maintain healthy levels. If the body reserves of glucose deplete, a process called gluconeogenesis will take place. During gluconeogenesis, glucose is synthesized from molecules that are not carbohydrates. 

Liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity, just below the diaphragm and has two lobes. The hepatic lobules are the structural and functional units of liver containing hepatic cells arranged in the form of cords. Each lobule is covered by a thin connective tissue sheath called the Glissons capsule. The bile secreted by the hepatic cells passes through the hepatic ducts and is stored and concentrated in a thin muscular sac called the gall bladder. The duct of gall bladder (cystic duct) along with the hepatic duct from the liver forms the common bile duct. The bile, pancreatic juice and the intestinal juice are the secretions released into the small intestine. The bile released into the duodenum contains bile pigments (bilirubin and biliverdin), bile salts, cholesterol and phospholipids but no enzymes. Bile helps in emulsification of fats, i.e., breaking down of the fats into very small micelles. Bile also activates lipases. Fats are broken down by lipases with the help of bile into di-and monoglycerides.

Liver is the largest gland of human body that accomplishes a diverse set of functions. Liver is known as chemical factory of the body. Most of the biochemical functions of the body are done by the liver. Detoxification is a major function of liver. Thus, conversion of toxic substances into non-toxic substances is done by liver. The toxic substances include xenobiotic compounds or may be formed by metabolic activities of the body. e.g., Prussic acid is converted into Potassium sulfocyanide (it is a non-toxic salt) by the liver.

Steroids like cholesterol are crystallisable lipids having four hydrocarbon rings, consisting of three cyclohexane and one cyclopentane ring and a long hydrocarbon side chain. In animals,  liver is the major site of cholesterol production. Cholesterol is an important constituent of bile produced in liver.

One of the most important biochemical roles of liver is detoxification i.e., conversion of toxic substances into non-toxic substance. The toxic substances cab be foreign or xenobiotic compounds or are formed by metabolic activities of the body. One of the detoxification strategies of liver is to make the xenobiotic and harmful chemicals water soluble by hydroxylating them. Once hydroxyl group is added, the chemicals become water soluble and can be easily excreted through urine route.

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.

The human liver carries out more than 500 metabolic functions, includ­ing the detoxification of harmful substances in the body. Over 2 quarts of blood pass through this important organ every minute of every day, filter­ing and transforming chemicals to keep the body clean. The liver also pro­duces bile into which fat-soluble toxins are attached and then discharged into the gastrointestinal tract.

The liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity, just below the diaphragm and has two lobes.  The bile secreted by the hepatic cells is released into the duodenum contains bile pigments (bilirubin and biliverdin), bile salts, cholesterol and phospholipids but no enzymes.  The bile secreted is a yellowish-green fluid that aids in the emulsification of fats. Bile is not an enzyme, but it does contain bile salts that emulsify large fat droplets. Hence, the liver does not produce digestive enzymes.

So, the correct answer is 'liver'.

Liver is the largest gland of the body. It plays a prominent role in the metabolism of carbohydrates, proteins, fats. It converts excess of glucose into glycogen and thus regulates sugar level in blood. It plays a major role in the breakdown of hemologbin. Thus option D is the correct answer. 

Bile or gall is a dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bile) and stored and concentrated in the gallbladder (gallbladder bile). After eating, this stored bile is discharged into the duodenum. Bile is not secreted by small intestine, large intestine or pancreas.

• 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. Hence the process of breaking down excess amino acids in the liver is known as Deamination. 

Angiotensin is a peptide hormone, that causes vasoconstriction and a subsequent increase in blood pressure. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. It plays an important role in the renin-angiotensin system. 

Animal flesh is composed of the most highly complex type of protein and requires vast amounts of uric acid to process. Uric acid is released into the system in amounts necessary to break proteins down into amino acids. Uric acid is a toxic substance and must be flushed out by the liver. Hence the carnivore's liver is designed with the capacity to eliminate ten times as much uric acid as the liver of man or other plant eaters. 

Glycogenolysis is the process by which glycogen stored in the liver and muscle cells of animals, is broken down into glucose to provide immediate energy and to maintain blood glucose levels during fasting. Glycogenolysis occurs in the liver and is stimulated by the hormones glucagon and epinephrine (adrenaline). It is the catabolic process where break down of glycogen occurs by the enzyme glycogen phosphorylase.

The colour of the stool is determined by the liver. The liver imparts a brown colour to the stool by releasing bile juices which is the normal case. In the case of the colour change of stool. it means that the liver is not functioning properly. For example. the stool is whitish grey in colour when the liver produces less bile juice or the flow of bile from the liver is blocked.

When carbohydrate intake exceeds energy needs, the liver converts excess glucose into fatty acids through a process called lipogenesis, which are then stored as triglycerides.

Glisson's capsule is the connective tissue sheath that covers the liver.

Bile is alkaline primarily due to the presence of sodium bicarbonate (NaHCO3), which helps neutralize acidic chyme entering the duodenum.

The liver is the site of synthesis for most plasma proteins, including albumin, fibrinogen, and prothrombin.

The urea cycle, which converts toxic ammonia into urea, occurs exclusively in the liver.

Kupffer cells are the resident macrophages of the liver that phagocytose old blood cells and pathogens.

Bile release is triggered by the presence of chyme in the duodenum, specifically the fat content which stimulates the release of the hormone cholecystokinin (CCK). CCK causes the gallbladder to contract, releasing bile to emulsify the fats.

The liver is the primary site for cholesterol biosynthesis in the human body. It regulates cholesterol levels by synthesizing it from acetyl-CoA.

The liver is a multifunctional organ that produces bile for digestion, synthesizes cholesterol for cell membranes and hormones, and stores/processes iron (ferritin).

Pepsin is in the stomach, trypsin is in the intestine, and ptyalin is in the mouth. Rennin is a gastric enzyme found in the stomach (specifically in infants), not the liver.

Bile is synthesized by hepatocytes in the liver. The gallbladder only stores and concentrates the bile produced by the liver.

Bile salts are primarily sodium and potassium salts of glycocholic and taurocholic acids. They are essential for the emulsification of fats.

The liver performs many functions like bile production, glycogen storage, and detoxification. Insulin is produced by the beta cells of the islets of Langerhans in the pancreas.

The liver stores glycogen but does NOT release glycogen into blood. Instead, it performs glycogenolysis to break down glycogen and releases glucose into blood. All other options ARE liver functions: bile production, bilirubin uptake/excretion, and urea synthesis.

Bile juice contains bile salts and pigments but lacks digestive enzymes. It aids digestion through the physical emulsification of fats.

The falciform ligament is a fold of peritoneum that attaches the liver to the anterior abdominal wall and the diaphragm.

Bile salts (like sodium glycocholate) lower the surface tension of fat droplets, breaking them into smaller particles to increase the surface area for lipase action.

Nicotinamide is indeed a vitamin (B3). Crypts of Lieberkuhn are in the small intestine, not the liver. Steapsin is pancreatic lipase, not amylase. Thus, statements II and III are incorrect.

The liver is responsible for the urea cycle, which converts toxic ammonia into urea. If the liver is removed, ammonia cannot be processed and will accumulate in the blood.

The liver acts as a modulator by storing or releasing glucose (glycogenolysis/glycogenesis), while the islets of Langerhans (pancreas) act as effectors by secreting insulin and glucagon to control blood sugar levels.

The liver is the primary site of the urea cycle, where ammonia (a toxic byproduct of protein metabolism) is converted into urea for excretion.

In many lower vertebrates, the liver serves as a hematopoietic organ, producing various blood cells including lymphocytes, unlike in mammals where this is primarily the role of bone marrow.

The liver is a major storage site for fat-soluble vitamins (A, D, E, K) and is involved in the synthesis of certain clotting factors related to vitamin K.

High-density lipoprotein (HDL) is known as 'good cholesterol' because it transports cholesterol from tissues back to the liver for excretion or recycling.

Bile's primary function is the emulsification of fats, which increases the surface area for lipase to act upon, facilitating digestion.

• In the liver, Glycogen a reserve food material is changed into glucose(sugar) (by gluconeogenesis) and released into the blood. when hepatectomy(surgical removal of the liver) is done it leads to rapid fall of blood sugar. Hence Blood sugar level falls rapidly after hepatectomy is a correct statement.
• During emergency conditions, the liver can convert proteins and fats i.e gluconeogenesis. Hence The glycogen of the liver is the principal source of blood sugar in case of emergency.is an incorrect statement
• So, the correct answer is 'Statement 1 is correct but statement 2 is incorrect'.

Urea is produced in the liver which is a breakdown product of amino acids if the liver is removed amino acids will not be metabolized and urea level will rise.

(i) Stomach has low pH (True). (ii) Liver contains bile, which emulsifies lipids (True). (iii) Large intestine does not secrete digestive enzymes (False). (iv) Proteases function in various locations, not just the small intestine (False).

The digestive glands associated with the alimentary canal include the salivary glands, the liver and the pancreas. Liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity, just below the diaphragm and has two lobes. The hepatic lobules are the structural and functional units of liver containing hepatic cells arranged in the form of cords. Each lobule is covered by a thin connective tissue sheath called the Glissons capsule. The bile secreted by the hepatic cells passes through the hepatic ducts and is stored and concentrated in a thin muscular sac, called the gall bladder. The duct of gall bladder (cystic duct) along with the hepatic duct from the liver forms the common bile duct.

Gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach.

Fat builds up in the liver cells, when the liver fails to break down, transfer and store fat effectively, causing abnormal liver function and inflammation, which can lead to liver scarring (known as cirrhosis). The main pigment in bile, bilirubin, is a waste product that is formed from hemoglobin (the protein that carries oxygen in the blood) and is excreted in bile. About half the bile secreted between meals flows directly through the common bile duct into the small intestine. The rest of the bile is diverted through the cystic duct into the gallbladder to be stored. Liver stores the fat soluble vitamins (A,D, E & K) and Vit B12.

Fibrin is a tough protein substance that is arranged in long fibrous chains; it is formed from fibrinogen, a soluble protein that is produced by the liver and found in blood plasma. In the clotting mechanism, fibrin threads form a meshwork for the basis of a blood clot. Most of the fibrinogen in the circulating blood is formed in the liver.

Glycogenesis is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage. This process is activated during rest periods following the Cori cycle, in the liver, and also activated by insulin in response to high glucose levels. Mostly glycogenesis occurs in the liver.

The yellow colour of the stools is due to the presence of bile pigments. Bile pigments are the excretory products. Bile is a bitter-tasting greenish-yellow alkaline fluid produced by the liver and stored in the gall bladder and secreted into the duodenum. It assists the digestion and absorption of fats by the action of bile salts, which chemically reduce fatty substances and decrease the surface tension of fat droplets so that they are broken down and emulsified. So, the correct answer is (a).