Liver is one of the most vital organ performing more that 400 different and crucial functions, the most for any organ in particular in the human body. It is the largest among the solid organs (or viscera, plural for ‘viscus’; medical term for internal organ). The other solid organs (or viscera) being kidneys, adrenals, spleen and pancreas. Heart, lungs, stomach and intestines forms the hollow visceras.

It is located in the right upper part of abdomen, medically described as to ‘occupy the right upper quadrant of abdomen’ (medically human abdomen is divided into 9 different quadrants for the purpose of study and descriptions). Liver, although is situated in the abdominal cavity but is very well covered and sits well protected in the rib cage of the right side, being separated from the chest cavity and right lung by a muscular sheath called ‘diaphragm. Hence, unless pathologically enlarged it is generally not felt (or palpable) during a clinical per abdominal exam. An enlarged or palpable liver is a clinical sign that might be an indication for further evaluating of ones’ liver condition and might be called for by your examining physician.

Although liver is a unilateral organ (or single) (unlike kidneys, lungs and gonads which are bilateral), structurally it is comprised of two distinct lobes: right and left. Right lobe is usually larger that the left and forms about 60-70% of the total liver volume (or weight). The normal weight of liver in a healthy adult is approximately 1200-1500gms or 2% of his total body weight. The total liver weight and its distribution between right and left can practically vary between individuals.

Liver is also a unique organ in its blood supply. Normally all human organ or tissues receive blood supply from a single source (medically termed ‘artery’; definition: a blood vessel that supplies blood to an organ from heart), but liver receives blood from two sources; one from artery (the hepatic or liver artery) and the other from portal vein (a unique system of blood vessels which gets blood from the intestines to the liver for the purpose of metabolism and detoxification of nutrients. Any change in the consistency of liver (like ‘liver cirrhosis’) can effect the flow mechanism in this portal vein system leading to a condition called ‘portal hypertension’. It is portal hypertension and its consequences that calls for a liver transplant in patients of liver cirrhosis. Once patients of liver cirrhosis develop portal hypertension and its consequences, he is medically referred to as a patients of end-stage liver disease (or failure).

Another property of liver that demands special mention here is its regenerative capability. This is a very unique property of liver which literally means ‘regrowth’, i.e if a part of liver is damaged by any pathological condition or removed surgically, the remaining part of liver regrows again to previous physiological level and there is no impact on the physiological performance of liver on the individual. This unique capacity of liver has a capacity to regenerate and maintain the normal liver function even if liver is damaged to an extent of 70-80%. Secondly liver keeps on functioning normally without showing any signs of problem or disease until it is 70-80% damaged. The signs of liver disease only starts appearing or showing up when the extent of damage gets more than 80% (which is beyond the capability of liver to resist and regenerate.