Define Liver?

The liver is the largest gland in the body, situated in the upper most part of the abdominal cavity on the right hand side beneath the diaphragm.  It is largely protected by the ribs.

The liver is divided into two main lobes, right and left.  The upper surface is convex and lies beneath the diaphragm; the under surface is irregular and presents the transverse fissure, the surface being broken by the passage of the vessels which enter and leave the liver.  The longitudinal fissure separates the caudate and left lobes on the under surface and the falciform ligament occupies a similar position on the upper surface of the liver.  The liver is further subdivided into four lobes (right, left, caudate and quadrate).  These are made up of lobules.  The lobules, which are polyhedral in shape, are composed of cubical liver cells and the ramifications of the vessels of the liver, all connected by the liver tissue.  The liver has a double blood supply by means of the hepatic artery and the portal vein.

The liver cells are nucleated polyhedral cells.  The protoplasm of the cells contains large numbers of enzymes.  Masses of these cells form the hepatic lobules which are roughly hexagonal in shape, about one millimeter in diameter and separated from one another by a connective tissue which run ramifications of the vessels transversing the liver.