1. The Digestive System

2. Function of the Digestive System
Break down foods
Extract nutrients needed for cellular activities (Respiration)

3. Four Steps in Digestion
Ingestion (eating food)
Digestion (breaking food down)
Absorption (taking in useful molecules)
Elimination (getting rid of physical waste)

4. Two types of digestion
Mechanical Digestion: Physical break down of large pieces of food into smaller pieces.
Chemical Digestion: Enzymes break down smaller food pieces into molecules the body can use.

5. 1) The Mouth Mechanical Digestion of all foods by teeth.
Chemical digestion of Carbohydrates by enzymes in the saliva.

6. 2) The esophagus Tube connecting the mouth to the stomach.
Peristalsis: muscular contractions that push food down the tube and through the system.

7. 2) The esophagus
Epiglottis: flap that prevents food from “going down the wrong pipe”

8. 3) The Stomach
Mechanical Digestion of all foods by muscular contractions/churning.
Chemical digestion of Proteins by enzymes (pepsin) and stomach acid.

9. 4) The Small Intestine
Chemical digestion of proteins, carbs, and fats is completed by:
Enzymes – added by the PANCREAS
Bile – created by the LIVER and stored in the GALLBLADDER
digests fats

10. 4) The Small Intestine
NUTRIENTS are ABSORBED by finger-like projections called VILLI and enter the blood

11. 5) The Large Intestine
WATER is ABSORBED from the undigested material leaving waste to be eliminated (poop)

12. A Journey Through the System
The Magic School Bus Gets Eaten

13. Malfunctions of the Digestive System
Heartburn
Ulcers
Constipation
Diarrhea

14. Heartburn
Cause: Acid from the stomach flows into the esophagus due to overeating/eating certain foods
Symptom: burning in chest
Treatment: Antacids

15. Ulcer Cause: Stomach acid/bacteria irritate the stomach lining
Symptom: abdominal pain
Treatment: Medication or Antibiotics

16. Constipation Diarrhea
Cause: Too much water absorbed in large intestines
Symptom: Trouble moving bowels
Treatment: drink extra water/eat fruits and fibers
Diarrhea
Cause: Not enough water absorbed in large intestine
Symptom: watery bowel movements
Treatment: medication (pepto bysmol) and stay hydrated