The Digestive System

2.  Ingestion
 Enters the mouth (ingested)
 Digestion
 As soon as food enters mouth digestion begins
 Breaks down food (mechanical and chemical process)
 Absorption
 Nutrients are absorbed in bloodstream
 Elimination
 Unused substances are eliminated

3.  BOTH!
 Mechanical digestion takes place when food is
chewed, mixed and churned
 Chemical digestion occurs when chemical
reactions break down food.

4. Mouth
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
Food passes through
these organs!

5.  Peristalsis!
 Waves of muscle contractions!

6.  Food does not pass through these organs! They
aid in the breakdown of food. (Helpers!)
 Tongue
 Teeth
 Salivary glands
 Liver
 Gallbladder
 Pancreas

7. Identify if mechanical and/or chemical
digestion is taking place……
What is the main job of the organ?

8. Mechanical digestion happens when you chew
your food with your teeth and mix it with your
tongue
Chemical digestion begins when the saliva mixes
in and helps to break down the food

9.  Thank you epiglottis! This flap saves us from
choking by protecting the windpipe to prevent
food from entering it.
 That way…the food goes right from the mouth to
the…..

10. A muscular tube
NO digestion takes place here!
Smooth muscles move the food downward
with the help of peristalsis!!!
Secretions from the mucus glands help keep food
moist!

11.  Muscular bag
 Mechanical and chemical digestion take place
here!
 Mechanically food is mixed in the stomach by
peristalsis
 Chemically food is mixed with enzymes and
hydrochloric acid
 Mucus is released to protect the stomach
 Food is now called CHYME.

12.  Food enters the duodenum…the first part of your
small intestine. MOST digestion takes place
here!
 Chemical digestion—bile added from gall
bladder and liver to break down fats, a solution
from the pancreas is mixed in to neutralize the
stomach acid and break down sugar.

13.  Absorption of broken down food (chyme) takes
place here. Nutrients move into the blood
stream to be delivered to all cells of your body.
 Peristalsis continues to force the remaining
undigested and unabsorbed materials into the
next stage…..

14.  When food enters, it is still a watery mixture.
 Water is absorbed here from the undigested
material. This helps to maintain homeostasis!!
 Peristalsis is slowing down and the material
moves into…..

15.  Muscles in the rectum and anus control the
release of waste from the body…….