Biology 104 Human Digestive System Anatomy

Abdominal Region 

 

 

The abdomen is the area inferior to the ribs that contains most of the digestive, 

reproductive, and excretory organs, collectively known as the viscera.   

 

The cavity in the abdomen that contains the viscera is the peritoneal cavity, 

which together with the thoracic cavity constitutes the coelom.  The diaphragm, a 

muscle that aids in inhalation,  forms a partition between the thoracic and abdominal 

cavities. 

 

 

Pressed against the inferior side of the diaphragm on the right side of the 

abdominal cavity is the dark brown liver. Its color is due to its rich blood supply.   The 

liver has a variety of functions, including the production of bile, which aids in the 

emulsification of fats.  Bile is stored temporarily in the gall bladder, a greenish sac 

embedded in the posterior face of the liver. 

 

 

Find the spleen, which is a fist-shaped, brown  organ on the left side of the 

abdominal cavity  that superficially  resembles the liver in color, due to a rich supply of 

blood.  The spleen functions in the storage, destruction, and production of red blood 

cells.  The spleen is not part of the digestive system, but is mentioned here because 

students always ask about it. 

 

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Inferior to the diaphragm on the left side of the abdominal cavity is the sac-like