1. Digestion, Excretion, & Respirtation
7. The Excretory System

2. Only waste products and extra water are left
Once food leaves the small intestine, most of its usable parts have been removed
Only waste products and extra water are left

3. Now it is time for the excretory system to go to work
Vocabulary:
Excretory system
A body system that removes wastes from the body

4. Some water is removed for use by the body
The undigested food moves from the small intestine into the large intestine
Some water is removed for use by the body

5. The solid waste is pushed through the large intestine by muscles
In the large intestine, tiny organisms called bacteria begin to feed on the waste

6. Vocabulary:
bacteria
One-celled living things that help break down waste in the large intestines

7. Finally, the waste reaches the end of the large intestine
It passes through the last part of the digestive system

8. This is known as the rectum
Vocabulary:
rectum
The last part of the large intestine

9. Muscles in the rectum push waste out of the body through the anus
Vocabulary:
anus
Opening in the body that allows solid waste to pass out of the body

10. Remember that your body needs to get rid of undigested food
The excretory system removes this solid waste from the body

11. But the body also needs a way to get rid of harmful chemicals
It also has to remove extra water

12. This liquid waste is also removed by the excretory system
The main organ of the excretory system are the kidneys

13. An organ that filters out water, salts, and chemicals
Vocabulary:
kidneys
An organ that filters out water, salts, and chemicals

14. The kidneys are two bean-shaped organs about the size of your fist
The kidneys act as filters

15. Urine is then produced by the kidneys
As blood passes through the kidneys, they filter out water, salts, and harmful chemicals
Urine is then produced by the kidneys

16. Liquid that is produced by the kidneys
Vocabulary:
urine
Liquid that is produced by the kidneys

17. Urine moves from the kidneys to the bladder
Vocabulary:
bladder
An organ that holds urine

18. When your bladder is full, you feel the need to empty it
Then urine passes from your bladder out of the body through the urethra

19. The body opening that allows urine to pass from the body
Vocabulary:
urethra
The body opening that allows urine to pass from the body