HUMAN ANATOMY AND PHYSIOLOGY

         LIVER

Anatomy the liver is a wedge shaped organ lying in the upper ibdomen below the diapharagm its major part is the right lobe which is situated on the right side and the left lobe with its apex in the left it weighs about 1.5kgs on an average in an adult healthy human being 
Surface it has two surfaces the superior convex and the inferior concave surface it has two borders the anterior sharp border and the blunt posterior border The upper surface is under the diaphragm the lower surface approximates with the stomach the duodenum etc 
Labes: the liver is divided into two lobes by a ligamentous band called falciform ligament the right lobe is larger as compared to the left lobe on the inferior surface are two bands which subdivide the organ from below into 4 compartments::
(1) Right lobe (2) Left lobe (3) Quadrate lobe and (4) Caudate lobe 
There are 4 fissures Important one is the transverse fissure which is called the porta hepatis through which passes:(a) Hepatic artery (b) Portal vein (c) Hepatic duct (d) Nerves and (5) lymphatic vessels 

Blood vessels of the Liver::

The liver is made up of lobules and lobules consist of liver cells there is connective tissue in between the lobules which contains blood vessels nerves bile ducts lymphatics etc 

Circulation in the Liver ::

The interlobular branches are the branches of the hepatic artery and the portal vein Thus both the arterial and venous blood percolate from the circumference to the centre of the liver lobules and drain into the central veins These veins combine to from hepatic veins and drain into the inferior vena cava Blood is brought to the liver from the stomach small intestine a part of the large intestine pancreas and the spleen 
                    There are bile canaliculi in between the hepatic cells of the hepatic lobule Hepatic cells secrete bile into these cancaliculi while it is finally drained by the hepatic ducts which pass out of liver through the portahepatis to terminate in the gall bladder 
                                The above two systems i.e the portal and the billiary systems explain structurally how the liver metabolises food and how it secretes the bile juice respectively 

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