1. The Human Excretory System The function of the excretory system is to excrete (get rid of) wastes that are not helpful to the body.

2. Waste Wastes that are removed include carbon dioxide, water, salt, urea and uric acid. All excreted wastes travel at some time in the blood.

3. Structures of the Excretory System 1.Skin 2.Lungs 3.Liver 4.Large intestine 5.Urinary System

4. Kidneys – filter wastes and excess water from the blood. 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. The Urinary System

5. The Kidneys 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.

6. Doctors analyze urine for disease; Normal urine contains water, urea and trace minerals. Sugar in urine indicates Diabetes Protein in urine indicates the kidneys are not working and the person, or animal, is very sick.