Liver: Biology PSC Notes
The liver is the largest internal organ inside the human body. It is a wedge-shaped organ that isreddish-brownin color. In human adults, the liver weighs approximately around1.4 Kg(1400g), it varies according to the gender. It is a part of the gastrointestinal system.
Facts about LiverLargest gland in the body.Found only in Vertebrates.Human Liver consists of 96% water.Largest waste disposal organ in the body.Filters about 1.7 liters of blood per minute.Produces approximately 1 Litre of bile per day.Most enzymes are secreted by the Liver.Only organ with the ability to regenerate naturally.The organ that liberates the largest amount of heat.Second largest organ in the body (first being the skin).Only organ that synthesizes and store Vitamin A (excess of, about 2 years) & Fat.If 25% of liver cells are left, while 75 % are damaged, the liver can regenerate within 8-25 days.
Structure of Liver(2)
| Item | Detail |
|---|---|
| Hepatic Artery | brings blood from the heart via the aorta |
| Portal Vein | brings digested food from the small intestine as well as carries blood into the liver |
Functions of Liver
The liver is capable of performing more than 500 functionsinside the human body. Some of the functions of the Liver are as follows:
Cleans the blood by detoxifying poisonous substances that enter the body.StoresVitamins (A, D, K & B12), minerals, fats, sugars and iron (in huge amounts).Helps in the clotting of the blood.Produces enzymes.Produces hormones such as Insulin-like Growth Factor-1 (IGF-1), Hepcidin, Betatrophin,etcSecretes proteins likeAlbumin, Prothrombin, Serum amyloid A (SAA) & Fibrinogen.Performs immunological functions by usingKupffer cellsto remove harmful substances in the bloodstream.Performs metabolic functions such as:Breaks down hemoglobin & produces Bilirubin.Breaks down proteins into amino acids.Breaking down of excess amino acids into Ammonia and which in turn combines with CO2to form urea.Produces a digestive juice calledbile, yellow-green liquidwhich breaks down fats in the bloodstream so they can be absorbed by the body.Breaks down the carbohydrates into glucose and it gets stored in the liver as glycogen.The digestive juice without enzyme – BileAs the liver is a major regulator of ammonia and plasma glucose levels, any imbalance in these levels may result in Hepatic encephalopathy, a condition where the brain function declines.
Because of these functions, liver is considered as thebiochemical laboratory of the human body.
Liver Diseases(8)
| Item | Detail |
|---|---|
| Alcoholic Liver DiseaseCancerCirrhosisFascioliasis | caused by parasite liver fluke |
| Fatty LiverJaundiceHepatitis (A, B & C)Reye syndrome | affects both liver and brain |
| Wilson disease (excess copper builds up, hereditary disease, affects the brain as well).📝 Read More:Vitamins📝 SideNotes:First successful whole human liver transplant occurred in | 1967.– by American physician Thomas Starzl |
| First successful deceased donor liver transplant (DDLT) in India | 1998 |
| First successful Living donor liver transplant (LDLT) in India | November 1998.– by RajashekarThe bile is stored in –Gall bladder |
| Largest endocrine gland in human body | Thyroid |
| Excessive consumption of alcoholic drinks causes damage to | Liver.(Previous PSC Questions: Women Civil Excise Officer, 2018)Dipsomania – Uncontrollable intermittent bouts of craving for alcohol |
| Which is not an Endocrine gland?(Previous PSC Questions: Junior Health Inspector, 2015)(A) Thyroid (B) Adrenal gland (C) Pituitary gland(D) LiverFat soluble Vitamins are mainly stored in | Liver.(Previous PSC Questions:Higher Secondary School Teacher- Homescience, Higher Secondary Education, 2016)The lipoprotein which removes cholesterol from peripheral tissues and transport it to liver is –HDL.(Previous PSC Questions: Senior Lecture/ Lecture In Neuro Surgery/ Gynecology, 2016)The lipoprotein which helps the transport of TAG synthesized by the liver is –VLDL.(Previous PSC Questions:Junior Scientific Officer, Chemical Examinations Laboratory, 2017)Vitamin A is mostly stored in which type of cells in the liver –Stellate/ito cells.(Previous PSC Questions: Senior Lecture/ Lecture In Neuro Surgery/ Gynecology, 2016)Activation of Gluconeogenesis in liver is achieved by inhibiting one of the key enzymes in the Glycolysis. Which of the following Enzyme is inhibited?(Previous PSC Questions:Junior Scientific Officer, Chemical Examinations Laboratory, 2017)(A) Hexokinase (B) Phospho Fructo Kinase-1(C) Pyruvate Kinase(D) Phospho Fructo Kinase-2 |