1. Human Excretory System
Topic 16

2. Excretion Urea The process of removing metabolic wastes
Metabolic waste formed by deamination of proteins (breaking down amino acids) in the liver

3. The KIDNEYS Filter wastes from the blood
Nephrons make urine from wastes
Fun Fact: Each kidney has about 1.25 million nephrons!
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4. The KIDNEYS
Substances needed by body are reabsorbed and return to the blood (water by osmosis, other materials by active transport!)
Salts, urea & excess water form Urine
Fun Fact: about 99% of water is reabsorbed!

5. How Kidneys Work http://www.youtube.com/watch?v=TzwPmz5V6Xg
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6. The URINARY SYSTEM Urine formed in Kidneys
Ureters- bring urine to the urinary bladder
Urinary Bladder- stores urine
Urethra- tube which carries urine out of the body

7. Image: http://kidney.niddk.nih.gov/kudiseases/pubs/yoururinary/

8. Malfunctions of the Excretory System
Kidney Stones:
High levels of Uric Acid & calcium crystallize
Very painful
Must pass stones or have them removed
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9. Image Courtesy of B. Beck
Kidney Stone in X-Ray
Image Courtesy of B. Beck

10. Organs of the Human Excretory System
Lungs
CO2 & Water from Cellular Respiration
Liver
Deamination- break down proteins
Kidneys
Water, Salts, Urea
Skin

11. The SKIN

12. The SKIN Sweating cools the body Sweat excretes water, salts & urea
Maintains HOMEOSTASIS
Images: Microsoft Clip Art

13. Brain Pop: http://www.brainpop.com/health/bodysystems/urinarysystem/