The Digestive System Accessory Organs
PLO’s
• C1 - analyze the functional
interrelationships of the structures of the
digestive system (pancreas, liver, gall
bladder)
• Several organs
and glands
contribute to the
digestive process
even though food
does not pass
through them
Pancreas
• Cells in the pancreas produce
pancreatic juice, which contains sodium
bicarbonate and several enzymes to
digest carbohydrates, proteins and fats
• Pancreatic juice is secreted into the
duodenum via the pancreatic duct
• The pancreas also has an endocrine
function (hormone secreting)
• insulin is produced in the pancreas and
secreted into the blood when blood
glucose is high (after eating)
• stimulates body cells to take up glucose
(lowers and regulates blood sugar
levels)
Liver
• Is considered the “gatekeeper” to the
blood as it regulates blood composition
in several ways
• Blood leaving the digestive tract first
goes to the liver via the hepatic portal
vein
• Blood leaves the liver via the hepatic
vein
Liver functions:
• Contributes to digestion by producing
bile (helps break down fats)
• Stores excess glucose as glycogen
• Converts glycogen to glucose when
needed
• Stores iron and some vitamins
• Removes and breaks down toxins from
the blood
• Regulates blood cholesterol levels
• Synthesizes blood proteins
• Produces urea from amino acid
breakdown (which is later excreted by
the kidneys)
• Breaks down hemoglobin from old red
blood cells; components of hemoglobin
breakdown are excreted in bile, giving it
its green colour
Fig. 12.10
Gall Bladder
• Attached to the liver
• Stores bile and secretes it into the
duodenum via the common bile duct
when fats are present
Appendix
• Not really an accessory organ since it
has no apparent digestive function
• Found at the end of the cecum (where
the small and large intestine join)
• Thought to have functions associated
with the immune system