1. BrainPOP | Digestive System

2. PURPOSE:
designed to break down food into smaller particles that can be used by the microscopic cells of the body.

3. 2 types of digestion…
Mechanical digestion: chewing, tearing, churning, and pushing of food by teeth (mastication), tongue & intestines
Chemical digestion: enzymes/acids/bile break down and change the molecules so they are able to pass into the blood/cells

4. Major Structures of the Digestive System
1. Mouth (oral cavity)
Site for ingestion
digestion begins!
Contain salivary amylase to start the digestion of carbohydrates
Gleek

5. Food tube connecting the mouth to the stomach
2. Esophagus
Food tube connecting the mouth to the stomach
Peristalsis – contractions that push food down the digestive tract
Epiglottis
A flap of tissue that closes over the trachea when you swallow
Epiglottis animation - YouTube

6. 3. Stomach
churns and mixes food you swallowed
Forms chyme
hydrochloric acid and pepsin begin protein digestion

7. Accessory Organs! (Organs that secrete substances into the digestive tract)
Salivary Glands
Pancreas – most enzymes for digestion are produced here (protease, more amylase, lipase) and secreted into the small intestine!!!
Liver – produces bile which emulsifies fats making it possible for enzymes to reach fat molecules and break them down
Gall Bladder – small organ that stores bile

9. 4. Small Intestine
most chemical digestion takes place here!!
Function is to absorb nutrients into blood
Villi: finger-like projections lining it increase the surface area for absorption. Contain capillaries that absorb amino acids and sugar, and lacteals (tiny lymph vessels) that absorb fats

12. 5. Large Intestine (Colon)
Main function is reabsorption of water into the body
Contains E. coli bacteria that produce vitamins
Feces is stored in the rectum before being removed from the body through the anus
Gut Fauna