Thirty per cent of the blood pumped through the heart in one minute passes
through the body's chemical factory, which is called the liver. Here, it
cleanses the blood and processes it into needed nutrition, which is distributed
to the tissues.
The liver also receives bright red blood from the lungs, filled
with vital oxygen to be delivered to the heart. The only part of the body which
receives more blood than the liver is the brain. The liver is located at the top
of the abdomen, just below the diaphragm and has two main lobes. It is the
largest gland in the body, 2.5 to 3.3 pounds in weight.
When we eat, more blood
is diverted to the intestines to deal with digestive processes; when not eating,
three-fourths of the blood supply to the liver comes from the intestines. It
also produces about two and one-half pints of bile in its ducts, which is
delivered to the gallbladder through a small tube called the "cystic
duct" for storage.
"Liver" is probably an appropriate name for
this gland, which makes the important decision as to whether incoming substances
are useful to the body or whether they are waste. The liver is an extremely
important organ and has multiple functions. The liver detoxifies the blood by
mixing them with bile and by chemical alteration to less toxic substances such
as the alteration of ammonia to urea.
Many chemical compounds are inactivated by
the liver through modification of chemical structures. The liver also converts
glucose to a storage form of energy called glycogen and can also produce glucose
from substances other than sugars and starches such as proteins.
The liver also
synthesizes triglycerides and cholesterol, breaks down fatty acids and produces
plasma proteins necessary for the clotting of blood such as clotting factors I,
III, V, VII, IX and XI. The liver also produces bile salts and excretes
bilirubin. A "lily-livered coward" was someone whose liver contained
no blood. The Greeks and Romans sacrificed animals to the gods before going into
battle. When the liver was examined, if it was healthy and the blood was bright
red, a victory was promised; if it was diseased or the blood was pale, defeat
was predicted.