1. Food, Food, Food is the Word
The Digestive System
Food, Food, Food is the Word

2. Function
To break down food into smaller molecules (nutrients) that the body can use
Carbohydrates  Simple Sugars
Proteins  Amino Acids
Fats  Glycerol and Fatty Acids
To get rid of solid wastes that remain after nutrients have been extracted

3. Types of Digestion Mechanical: PHYSICAL breakdown of food EX. Chewing
Chemical:
CHEMICAL breakdown of food by enzymes or other digestive juices
EX: Amylase found in saliva breaks down Carbs

4. The Path of Digestion Mouth Esophagus Stomach Small Intestine
Large Intestine
Accessory Organs
Pancreas
Liver
Gall Bladder

5. Path of Digestion: Mouth
Begins the breakdown of food
Types of Digestion:
Mechanical:
Chewing (Teeth and Tongue)
Chemical:
Saliva that contains enzymes
Molecules that are digested:
Carbohydrates (Enzyme = Amylase)
Swallowing Animation

6. Path of Digestion: Esophagus
Brings food from mouth to stomach
Food is now called a BOLUS
Epiglottis:
Flap of tissue at back of throat that prevents food from entering the wind-pipe
Peristalsis:
Wave-like contractions that move bolus to stomach
Click Here for animation

7. Path of Digestion: Stomach
Further breaks down bolus for nutrient extraction
Types of Digestion:
Chemical Digestion:
Gastric juices (VERY ACIDIC) containing enzymes breakdown:
Continued digestion of Carbohydrates
First PROTEIN digestion
Mechanical Digestion:
Churn, Churn, Churn!
Bolus turned to CHYME

8. Path of Digestion: Small Intestine
Further breaks down chyme for nutrient absorption by blood stream
S.I. lined with tiny projections called VILLI
Villi contain capillaries that absorb nutrients into blood stream
Nutrients move into blood stream by what process (Think H to L!)?
DIFFUSION!!!!!!!!!
Type of digestion:
Chemical Only:
Continued digestion of Carbohydrates
Continued digestion of Proteins
First FAT digestion

9. Helper Organs: The Video Clip

10. Helper (Accessory) Organs
Food DOES NOT pass through these organs
These organs secrete substances to aid in digestion
Pancreas:
Secretes enzymes into S.I for digestion
Secretes a base into S.I. to neutralize stomach acid WHY??
So digestive enzymes aren’t denatured and can work!
Liver:
Produces and secretes BILE that breaks down fats
Gall Bladder:
Stores the bile

11. Path of Digestion: Large Intestine
Removes WATER from undigested chyme
Lined with bacteria (E. coli)
Proper water absorption is necessary to keep you regular!
Not enough water absorbed = DIARRHEA
Too much water absorbed = CONSTIPATION
Final stop for undigested material…the anus!

12. Digestive System Fill-In

13. Digestive System Fill-In Answers