1. The Digestive System

2. mouth

3. The Digestive System Ingestion
 food is taken into the body through the mouth
2) Digestion
 food is broken down (physically and chemically)
3) Absorption
 nutrients are moved into the blood
4) Elimination
 solid waste passes from the digestive system
out of the body

4. Why is Digestion Important ?
When we consume food, the body needs to break down
the food into smaller molecules of nutrients for the
system to absorb the nutrients into the blood stream

5. How does the digestive system work ?
1) & 2) 3) 4) 5) 6) 7)

6. Mechanical vs. Chemical Digestion
Mechanical Digestion
 begins in your mouth as your teeth tear and grind food into
small pieces
 continues in the esophagus, stomach, and small intestine by
pushing food along, churning and breaking it into smaller particles.

7. Mechanical vs. Chemical Digestion
 process where acids, bases and enzymes released into the
digestive track respond to semi-solid food lumps and break it
down further
 for example: in the stomach enzymes, hydrochloric acid
(HCl), and mucus help the body extract
nutrients from food

8. What are the roles of the other organs? LIVER
☺ the liver produces bile, a substance that helps to break down fats
☺ nutrients arriving from the small intestine into the liver are made
into products that can be more easily used by the body
☺ toxins are generally broken down into less toxic substances
☺ the liver is the body's 'detoxifier'.

9. What are the roles of the other organs? GALL BLADDER
☺ bile produced in the liver is transferred to the gallbladder where
it is stored until needed for digestion of fats

10. What are the roles of the other organs? PANCREAS
☺ releases powerful digestive enzymes required for chemical digestion
when food reaches the lower stomach
☺ also secretes another substance to help neutralize stomach acid
☺ the hormone insulin is made by the pancreas
☺ insulin helps to balance blood sugar levels in the body

11. Did you know? ☺It takes one to two days for food to pass through
the entire digestive system
☺The small intestine is about 20 feet long when laid out flat
☺ When you smell food signals are sent to your brain. Your
brain shoots out impulses that:
 make your mouth water
 make your stomach contract (hunger)
 make the intestines start leaking
digestive chemicals
☺ The liver is the only organ in the body that is capable of
regenerating if parts of it are removed (eg. surgery) or
become diseased

12. Peristalsis peristalsis is wave-like movements of muscles
peristalsis starts in the
esophagus and continues
along the entire digestive
Path
peristalsis works in one direction
only
reverse peristalsis occurs when
we vomit

13. A B

14. A B C D E F G H
A ___________________
B ___________________
C____________________
D ___________________
E ___________________
F ___________________
G ___________________
H ___________________