1. Digestive & Excretory Systems

2. The Digestive System

3. Digestion Digestion is the processing of food. There are two types.
Mechanical Digestion
Chew
Tear
Grind
Mash
Mix
Chemical Digestion
Stomach acid
Saliva

4. Peristalsis
Peristalsis is the way food is pushed along by the movement of involuntary muscles. It only works in one direction.
Peristalsis happens in the esophagus and in the stomach.

5. Stomach Shaped like a “J” Left side of body
Mucous membrane for protection from stomach acid
Functions
Mixes food
Stores food for later
Starts digestion of protein and fats
Activates some enzymes
Destroys some bacteria
Absorbs water

6. Small Intestine 20 feet long! Has three regions Duodenum Jejunum Ileum
Absorbs 80% of water, plus vitamins, minerals, and proteins
Food stays here 4 – 8 hours

7. Villi
Villi are tiny finger-like extensions in the walls of the small intestine.
They allow food to be absorbed faster.

8. Large Intestine 5 feet long Regions Food stays here 10 -12 hours
Cecum – Appendix
Colon
Ascending
Transverse
Descending
Rectum
Anal canal
Food stays here hours

9. Jobs of the Large Intestine
Mechanical digestion
Chemical digestion
Absorbs water and vitamins
Concentrates/eliminates wastes

10. Liver Detoxifies/removes drugs and alcohol
Factory for antibodies and bile
Stores vitamins and sugars until your body needs them

11. Gallbladder & Pancreas
Storage tank for bile (a greenish-yellow liquid) that helps your body break down and use fats
Located under your liver
Shaped like a pear
Helps you digest food by breaking down sugars
Digests the food you eat
Takes the nutrients out of your food so your body can use it

12. Gallbladder & Pancreas

14. Interesting Facts
Food is in your digestive system for about 24 hours.

15. Your stomach stretches when you eat like a balloon being filled with air.

16. You have a trap door called the epiglottis to cover your windpipe when you swallow.

17. Your stomach mashes your food the way a baker kneads dough for bread.

18. The Excretory System

19. Jobs of the Excretory System
Removes
Excess water
Urea: waste product from proteins
Carbon dioxide
Other wastes from our blood

20. Parts of the Excretory System
Kidneys – filter out excess water and urea
Ureters – tubes that take urine from the kidney to the urinary bladder.
Urinary Bladder – a sack that stores urine.
Urethra – small tube that leads urine out of the body.
Lungs – filter out carbon dioxide from the blood
Skin – excretes water as sweat, which contains some trace chemical wastes, including urea.

21. The Kidneys Located near hips on back side
Every drop of blood in your body is filtered by your kidneys more than 300 times per day!
Kidneys eliminate urea, minerals and excess water.
Kidneys regulate the amount of water we need to maintain in our bodies.