What is the difference between mechanical and chemical digestion? Walk-In Take out notebook, folder, pencil box. Copy the question and answer in sentences: What is the difference between mechanical and chemical digestion?

Answer Mechanical digestion breaks food down by grinding and chewing it. Chemical digestion breaks food down by adding chemicals from the body to it, to make a liquid. Mechanical does not change the food, just makes it smaller. Chemical changes it by chemical reactions.

The Digestive System

In this activity, you and your partner will… Try to answer some questions about the digestive system, to see what you may already know! Label and color a diagram of the digestive organs. Read and take notes about each part of the digestive system.

Part A -Try to Answer! Write your answer/best gues on your sheet. 1. How long are your intestines? 2. How long are the intestines of a full grown horse? 3. How long does chewing take? 4. How long does swallowing take? 5. Food sloshes in the stomach. How long can this last? 6. How long does it take for food to move through the intestine? 7. Food drying up and hanging out in the large intestine can last how long? 8. How many pounds of peanut butter do Americans eat in a year? 9. How many pounds of chocolate do Americans eat in a year? 10. In your lifetime, your digestive system may handle how many tons of food?

Answers! 1. How long are your intestines? 25 feet 2. How long are the intestines of a full grown horse? 89 feet 3. How long does chewing take? 5-30 seconds 4. How long does swallowing take? 10 seconds 5. Food sloshes in the stomach. How long can this last? 3-4 hours 6. How long does it take for food to move through the intestine? 3 hours 7. Food drying up and hanging out in the large intestine can last how long? 18 hours to 2 days 8. How many pounds of peanut butter do Americans eat in a year? 700 million pounds 9. How many pounds of chocolate do Americans eat in a year? 2 billion pounds 10. In your lifetime, your digestive system may handle how many tons of food? 50 tons of food

Part B -Parts of the Digestive System Label your diagram as it is indicated on your sheet. DO NOT COLOR UNTIL YOU ARE DONE WITH THE REST OF YOUR SHEET! Teeth/Mouth Esophagus Stomach Small Intestine Large Intestine Pancreas Liver Gallbladder Rectum

Part C - The Digestive System Function: moves and breaks down food into smaller, usable nutrients. Nutrients: the body needs to absorb different nutrients in order to function Proteins Carbohydrates Fats Water Vitamins Minerals

Part D -Types of Digestion Chemical - Chemical changes actually change the food into different substances Chewing a cracker – the cracker is broken into smaller pieces and the saliva in our mouth produces a chemical change – the starches in the cracker are changed to sugars Mechanical - The physical process of breaking food into smaller pieces. Chewing food, stomach mashing and pounding food during peristalsis.

Part E –Organs of the Digestive System Read each slide carefully. Write down the main function for each part of the digestive system.

Teeth grind and spit breaks up food Mouth Teeth grind and spit breaks up food Salivary glands secrete 1-2 liters of spit a day

Moves food to stomach through peristalsis Esophagus Moves food to stomach through peristalsis Peristalsis- the muscular action of material moving through the digestive system by wave-like action of smooth muscles.

Chemicals break down the food Stomach Chemicals break down the food The stomach is lined with a thick mucus so the stomach acid does not eat away at itself.

Absorbs nutrients 22 feet long Small Intestine Absorbs nutrients 22 feet long Villi (small structures in the small intestine) contain folds that absorb the nutrients.

Most of the solid material (poo) that remains is compacted and stored. Large Intestine Absorbs water Most of the solid material (poo) that remains is compacted and stored.

Filters blood & produces bile Liver Filters blood & produces bile Go Rattlers! Bile is a chemical that helps break down food.

Produces the chemicals called insulin and glucagon Pancreas Produces the chemicals called insulin and glucagon Without these chemicals from your pancreas your body would die of starvation.

Gallbladder Stores bile made by the liver; secretes (releases) bile to small intestine

Stores feces (solid waste product) (“poop”!) Rectum Stores feces (solid waste product) (“poop”!)

THE END

If you are finished with your writing… Now color code the digestive system diagram.