2.  Your cells need a lot of energy for daily activities.  Cells use nutrients, which are substances in food, for energy, growth, maintenance, and repair.  The digestive system breaks down the food you eat into nutrients that can be used as building materials and that can provide energy for cells.

3.  Digestion is the process of breaking down food into a form that can pass from the digestive system into the bloodstream.  There are two types of digestion: mechanical and chemical.

4.  Mechanical Digestion  Is the breaking, crushing, and mashing of food.  Ex: Chewing is a type of mechanical digestion. Chewing creates small pieces of food that are easier to swallow and digest than large pieces are.

5.  Chemical Digestion  Is the process in which large molecules of food are broken down into smaller molecules so that they can pass into the bloodstream.  An enzyme is a chemical that the body uses to break down large molecules into smaller molecules.  Enzymes act like chemical scissors, they “cut up” large molecules into smaller pieces. *Without mechanical digestion, chemical digestion would take days instead of hours*

6.  In your mouth, teeth grind food  mechanical  chemical  In the small intestine, most nutrients are broken down by enzymes  mechanical  chemical

7.  In your mouth, teeth grind food  mechanical  chemical  In the small intestine, most nutrients are broken down by enzymes  mechanical  chemical

8.  The Mouth  The Esophagus  Stomach  Small Intestine  Large Intestine

10.  The Mouth  Digestion begins in the mouth with both mechanical and chemical digestion.  Teeth, with the help of the jaw, break and crush food.  As you chew, food is moistened by saliva.  Saliva contains many substances, including an enzyme that begins the chemical digestion of starches in food.

11.  The Esophagus  Once food has been chewed, it is swallowed and moves through the throat and a long tube called the esophagus.  Waves of muscle contractions move food into the stomach. Ex: muscle moves food along the same way you move toothpaste from the bottom of the tube with your thumbs

12.  Stomach  The stomach is a muscular bag that crushes food and contains acids and enzymes for killing bacteria and breaking down protein.  The stomach wall contains layers of muscle so the stomach can churn and mix food.  This is the final step of mechanical digestion.  Food sits in the stomach for a few hours before moving to…..

13.  Small Intestine  The small intestine is a muscular tube were most chemical digestion takes place.  Most nutrients are absorbed in the small intestine as well.  Food travels from the stomach into the small intestine in the form of chyme.  Chyme is food reduced to a soupy mixture

14.  Large Intestine  After food moves through the small intestine, it moves to the large intestine.  In the large intestine, water and nutrients are absorbed.  Most solid material that remains is waste  Waste is compacted and stored until the body eventually eliminates it.

15. Small IntestineLarge Intestine  After nutrients are broken down, they are absorbed into the blood stream and used by cells  Removes water from mostly-digested foods, absorbs vitamins, and turns food waste into semi-solid waste.

16.  Pancreas-makes fluids that break down every type of material found in foods Ex: these include proteins, carbohydrates, fats, and nucleic acids  Liver-makes and releases a mixture called bile that is stored in the gall bladder ◦ Bile breaks up large fat droplets into very small fat droplets

17.  HOW LONG ARE YOUR INTESTINES? At least 25 feet in an adult. Be glad you're not a full- grown horse -- their coiled-up intestines are 89 feet long!  Chewing food takes from 5-30 seconds  Swallowing takes about 10 seconds  Food sloshing in the stomach can last 3-4 hours

18.  It takes 3 hours for food to move through the intestine  Food drying up and hanging out in the large intestine can last 18 hours to 2 days!  Americans eat about 700 million pounds of peanut butter.  Americans eat over 2 billion pounds of chocolate a year.  In your lifetime, your digestive system may handle about 50 tons!!

19.  http://www.brainpop.com/health/bodysyste ms/digestivesystem/ http://www.brainpop.com/health/bodysyste ms/digestivesystem/