Digestive System

• The three main functions of the digestive system are:

  1. Break down food
  2. Absorb nutrients
  3. Get rid of wastes
• The order of the steps in the digestive system is:

  1. Mouth (Teeth, tongue, salivary glands)
  2. Throat (pharynx)
  3. Epiglottis
  4. Esophagus
  5. Stomach
  6. Small intestine
  7. Appendix
  8. Large intestine
  9. Rectum
  10. Anal sphincter
• Teeth physically break down the food.
• The tongue moves food around and guides it to the teeth or the back of the mouth.
• Salivary glands lubricate the food and mouth. Saliva contains amylase, an enzyme that breaks down carbs.
• The pharynx is at the back of the mouth. Five areas of the body meet here. (Mouth, nasal passage, esophagus, trachea and eustachian tube. )
• The epiglottis is a flap that covers the esophagus or the trachea.
• The larynx "adam's apple" is on top of the trachea.
• The esophagus carries food down to the stomach. "Peristalsis" are the muscular rings that contract to push food down to the stomach.
• The stomach breaks down food physically and chemically. It contains hydrochloric acid and pepsin, an enzyme that breaks down protein.

  It has special cells in the lining that make mucus, which coats the stomach so you don't digest yourself.
• The small intestine finishes breakdown and begins absorption.

  "small" means thinner, it's actually about 7m long.

  Contains villi and microvilli to increase the surface area for absorption.
• There are several other helper organs

  1. Pancreas (makes 28 enzymes and also insulin)
  2. Liver (makes bile which raises ph back up, breaks down fat)
  3. Gall bladder (Stores bile until needed)
• The appendix is a vestigial structure on the border of the small intestine.
• The large intestine is only 2m long but thicker. It absorbs water.
• The rectum holds waste until ready.
• The anal sphincter is a circular muscle. It is the exit for waste.