Is part of the Digestive tract that lies between the stomach and large intestines

The large amount of digestion occurs here

Food passes into Small Intestines from stomach by the “pyloric sphincter”

Comprises:

   -  Duodenum  -  on average – 10 inches long
   -  Jejunum   -  on average – 8 feet long
   -  Ileum     -  on average – 11.5 feet long

The diameter of the small intestines is smaller then large intestines – hence the name
However the small intestines is almost 5 times longer then the large intestines

Peristalsis – is the function of muscles to cause a wave-like contraction in order for food to move in a certain direction

Absorption – The inner walls of the small intestines is lined with rugae or plicae circulares.
These are wrinkles that allow a greater surface area and absorption occurs.  Secreation of enzymesand other molecules allow for nutrients to pass from the intestines into the blood stream.

The Jejunum allows for the larges extent of absorption. 

The following are absorbed else where:

   -  Iron                    [Duodenum]
   -  Water                [Everywhere]
   -  Lipids              [Everywhere]
   -  Vitamin B12    [Terminal Ileum]
   -  Bile Salts          [Terminal Ileum]
   -  Sodium             [Active transport]
   -  Glucose            [Co-transport]
   -  Amino Acid      [Co-transport]
   -  others