Download The Digestive System

The Digestive System
Digestion

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The process of breaking down food into
smaller molecules that can be absorbed
and moved into the blood
Two Types:
1. Physical (Mechanical) – food is chewed,
mixed or churned
2. Chemical – Chemical reactions help break
down food into small molecules
Digestion begins in the mouth
Teeth and chewing help physically break
down the food
 Saliva contains mucus and enzymes that
break down starch into sugar

– helps chemically break down food
The Esophogus
Connects the mouth to the stomach
 No digestion takes place here
 Brings food down by muscle action called
peristalsis
 Epiglottis – part of body that prevents
food from going into the lungs

Food enters the Stomach

Chemically breaks down food when it is
mixed with hydrochloric acid and other
chemicals/enzymes
– Also destroys bacteria in food
Physically breaks down food by peristalsis
 Food becomes chyme (thin, watery liquid)

Small Intestine
Completes chemical
digestion
 Smaller molecules can
now be absorbed and
enter cells through villi
 Villi – folds in the
intestines that increase
surface area
 Your small intestines
are 4–7 meters long

Liver and Pancreas
Produces the chemicals needed for
digestion
 Liver makes bile – digests fats
 Chemicals made in the pancreas digest
carbohydrates, proteins and fats
 The Pancreas also makes insulin, which
allows glucose to pass to the blood

Large Intestine
Absorbs water and
helps your body
maintain homeostasis
 Collects undigested
food to be removed
from the body
 Undigested food is
stored in the rectum
and is released
through the anus
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The Digestive System