The pancreas is a large gland found
behind the stomach and is connected to the small intestine by two
ducts or tubes. One of the main roles of the pancreatic juice
produced by the pancreas is to neutralise the acidic chyme in the
upper small intestine.
When chyme enters the duodenum the pancreas is
stimulated to secrete the three types of pancreatic juice, called
amylase, trypsin and lipase. Amylase changes starch
into simple sugars, trypsin breaks down partially digested
proteins, and lipase splits fats into fatty acids and glycerin.
The juice also contains enzymes, which are capable of
digesting all types of food, and sodium bicarbonate which is a
strong base. The concentration of sodium bicarbonate is about the
same as the concentration of the hydrochloric acid produced by the
stomach. When the acid and base are mixed in the small intestine
they neutralise each other and the products are reabsorbed. This
process maintains the acid-base balance of the blood by making sure
there is not too much acid or base in the body.
The pancreas produces slightly less sodium carbonate
per kilogram of body weight than amount of hydrochloric acid
produced by the body. Therefore there is more hydrochloric acid in
the intestine, which means that the chyme will be slightly acidic.
The pancreas also releases enzymes that stimulate the liver to
produce bile and makes the hormone insulin, which transports
sugar. In some people the pancreas does not function correctly and
insulin is not produced. This disease is called diabetes, which can
be quite serious if not treated.