Gross anatomy
The liver is the largest gland in
the body (Weight 1.36 kg) . It is located on the right
side of the upper abdomen. It is a soft, "wedge-shaped"
organ, reddish-brown in color because of the rich
supply of blood flowing through it.
Liver is made of two lobes. The right
lobe is the larger, measuring 6 to 7 inches in length.
The left lobe is approx 3 inches in length.
The liver is covered entirely by
visceral peritoneum, except for a small area where
it connects to the diaphragm, The peritoneum folds
back on itself to form the falciform ligament and
the right and left triangular ligaments. The falciform
ligament divides the liver into a left lobe, and a
right lobe. If seen from visceral side, two more lobes
are visible : the caudate lobe and below this the
quadrate lobe. From behind, ligamentum venosum divides
these lobes and ligamentum teres divides the caudate
from the quadrate lobe. How does Liver look when seen
through microscope? When viewed under a microscope,
the liver is seen as large number of hepatic lobules.
The hepatic lobule looks like a six-sided cylinder.
A central vein runs through the center of the lobe.
Liver cells are arranged in the form of cords. Between
these cords lies thin-walled blood vessels called
sinusoids.
Blood
supply of liver
Two major blood vessels supply liver.
Hepatic artery
Portal vein
The hepatic artery comes off the
celiac trunk which in turn comes from aorta. The venous
blood from the digestive tract is collected by the
portal vein, which then supplies blood to liver. The
hepatic veins drain blood from liver into the inferior
vena cava.
Biliary
System
Liver produces bile. Bile is then
collected in bile capillaries, which merge to form
bile ducts. Bile duct drain into right and left hepatic
ducts, which combine to form common hepatic duct.
The bile is stored and concentrated in gall bladder
during fasting state. When person takes food, Gall
bladder contracts, emptying bile into cystic duct,
shich combines with common hepatic duct to form common
bile duct. Common bile duct drains bile into duodenum
through ampulla of vater, a sphincter which controls
bile flow into duodenum.
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