The Digestive System

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

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

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.

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

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

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

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

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

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

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

A Journey Through the System https://www.youtube.com/watch?v=VwrsL-lCZYo The Magic School Bus Gets Eaten

Malfunctions of the Digestive System Heartburn Ulcers Constipation Diarrhea

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

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

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