The Digestive System

1. The Digestive System

2. The Digestive System Functions: • Breaks downfood into molecules the body can use. • Absorbs nutrients into the blood • Eliminates wastes from the body

3. Digestion Two types of digestion: 1) Mechanical: physical breaking apart of food Ex: Chewing, “Smushing”

4. Digestion Two types of digestion: 2) Chemical: enzymes break food into molecules Ex: saliva, stomach acid

5. The Digestive Journey 1) Digestion begins at the mouth. 1) Teeth: mash and grind food 2) Salivary Glands: make saliva, which breaks down food & makes it easier to swallow

6. 2) After food is swallowed, it travels through the esophagus. • Food is moved through this tube by muscles contracting and squeezing. This process is called peristalsis • The esophagus delivers food to the stomach

7. 3) The stomachis primarily composed of muscles. • Food is digested by mechanical and chemical digestion until it turns into a soupy substance called chyme.

8. 4) Small Intestine • The nutrients in chyme are absorbed into the bloodstream through the walls of the small intestine.

9. Absorption • Digestive juices from the liver and pancreas join the chyme. • This turns the chyme into molecules small enough to get in blood.

10. Absorption • Villi: small, fingerlike projections, that help small intestine absorb nutrients

11. 5) Large Intestine • Waste enters the large intestine as a soupy material, but it is changed into a semisolid waste called feces or stool.

12. The rectum is the last part of the large intestine. It stores feces until it can be expelled. • Feces pass through to the outside of your body through an opening called the anus.

13. Other Digestive Organs Liver: Makes bile (fluid that helps digest)

14. Other Digestive Organs • Gall Bladder: stores and releases bile

15. Other Digestive Organs • Pancreas: Produces enzymes to help digest food

16. Other Digestive Organs • *Food does not pass through the liver, gall bladder, or pancreas.