Liver
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.
The liver cleanses the blood and processes nutritional molecules, which
are 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, weighing 2.5 to 3.3
pounds. 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 blood cells 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 converts glucose to
a storage form of energy called glycogen, and can also produce glucose
from sugars, starches, and 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.