Transcript 15.6 Digestion Part1

The Mammalian Digestive System
The digestive system in mammals is
responsible for the chemical breakdown
of food and its absorption from the gut
Much of the food that we consume contains
macromolecules that are too large to be
absorbed and utilised by the body cells
Starch and protein are polymers and
lipids are large molecules
Polymers need to be broken down into their
monomers and large molecules into smaller
constituents, if absorption is to occur
The Mammalian Digestive System
Digestion is the process of breaking
down large food molecules into
smaller molecules that can be
absorbed and used by body cells
In humans, hydrolytic enzymes are
responsible for the chemical digestion
of starch, protein and lipids
Hydrolytic enzymes (hydrolases) are
manufactured in various regions
of the digestive system
The Mammalian Digestive System
The organs of the digestive system are
made up of the gastrointestinal tract (GI)
and accessory structures
The gastrointestinal tract or alimentary canal is a
continuous tube running from the mouth to the anus
The major organs of the alimentary canal are:
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The mouth
The oesophagus
The stomach
The small intestine (duodenum and ileum)
The large intestine (colon, rectum and anus)
Mouth
Salivary glands
Oesophagus
Liver
Stomach
Pancreas
(in loop of duodenum)
Colon
Small intestine
(duodenum + ileum)
Rectum
Anus
The Stomach & Duodenum Outlined
on a Barium Meal X-Ray
Duodenum
Stomach
The Stomach & Intestine Outlined
on a Barium Meal X-Ray
Oesophagus
Stomach
Intestine