1. Section 10.3 Your Excretory System Slide 1 of 21 Objectives Identify the organs of excretion in the body and their functions. Explain how the kidneys remove wastes from the blood and produce urine. Section 10.3 Your Excretory System Describe behaviors that can keep your excretory system healthy.

2. Section 10.3 Your Excretory System Slide 2 of 21 Health Stats This graph compares the amount of water you excrete in sweat and urine on a normal day and on a hot day. In a paragraph, discuss how weather affects water loss.

3. Section 10.3 Your Excretory System Slide 3 of 21 Excretion is the process by which the body collects and removes wastes. Organs of Excretion Several organs in the body are involved in waste collection and removal liver lungs skin kidneys

4. Section 10.3 Your Excretory System Slide 4 of 21 The liver converts impurities and poisons in the body to less harmful substances. Liver The liver forms urea from a harmful waste product of protein breakdown.

5. Section 10.3 Your Excretory System Slide 5 of 21 The lungs remove carbon dioxide and some water from the body. Lungs and Skin Sweat glands in the skin serve an excretory function because water and urea are excreted in perspiration.

6. Section 10.3 Your Excretory System Slide 6 of 21 The kidneys, which are the major organs of the excretory system, filter urea and other wastes from the blood. Kidneys You have two kidneys, each about the size of a fist. Urine is a watery fluid produced by the kidneys that contains urea and other wastes.

7. Section 10.3 Your Excretory System Slide 7 of 21 Kidney The kidneys produce urine by filtering urea and other wastes from the blood. Ureter One ureter extends from each kidney. The ureters carry urine from the kidneys to the bladder. Bladder The bladder is a saclike muscular organ that stores urine. Urethra Urine travels through the urethra as it exits the body. The Excretory System

8. Section 10.3 Your Excretory System Slide 8 of 21 Each kidney contains about a million nephrons, tiny filtering units that remove wastes and produce urine. Filtration of Wastes The nephrons filter wastes in stages. Needed materials and wastes are filtered from the blood. Most needed materials are returned to the blood, and the wastes are eliminated from the body.

9. Section 10.3 Your Excretory System Slide 9 of 21 Blood enters the kidneys. Filtering Out Wastes Blood flows through smaller blood vessels until it reaches a cluster of tiny blood vessels in a nephron called a glomerulus (gloh MUR yoo lus). Urea, salts, glucose, and water are filtered from the glomerulus into a thin-walled capsule.

10. Section 10.3 Your Excretory System Slide 10 of 21 As the filtered material flows through the tube, the glucose, most of the water, and other needed materials pass from the tube back into the blood. Formation of Urine Urea and other wastes, such as excess vitamins and harmful substances, stay in the tube.

11. Section 10.3 Your Excretory System Slide 11 of 21 A Nephron Blood flows from an artery into a nephron. In the glomerulus, urea, water, glucose, and other materials are filtered from the blood. These materials pass into a capsule that surrounds the glomerulus. The materials pass from the capsule into a long, twisting tube. The tube is surrounded by blood vessels. As the filtered material flows through the tube, most of the water and glucose are reabsorbed into the blood. Most of the urea and other waste stay in the tube. After the reabsorbing process is complete, the liquid that remains in the tube is called urine.

12. Section 10.3 Your Excretory System Slide 12 of 21 Click above to go online. For: Updates on the excretory system

13. Section 10.3 Your Excretory System Slide 13 of 21 To help your kidneys function at their best, it is important to drink plenty of water and to see a doctor if you have symptoms of an infection. Keeping Healthy

14. Section 10.3 Your Excretory System Slide 14 of 21 Because many of the waste products filtered by your kidneys are harmful, it is best if they are diluted as much as possible. Drinking Water

15. Section 10.3 Your Excretory System Slide 15 of 21 Urinary tract infections, which are bacterial infections of the urethra or bladder, are common disorders. Treating Infections Symptoms of urinary tract infections include frequent, painful urination and blood in the urine.

16. Section 10.3 Your Excretory System Slide 16 of 21 Kidney stones are pebblelike masses of salts, and often calcium, that form in the kidneys. Preventing Kidney Stones Drinking plenty of fluids and eating a diet that is low in salt may reduce your risk of developing kidney stones.

17. Section 10.3 Your Excretory System Slide 17 of 21 Kidneys that are damaged from an injury, diabetes, uncontrolled high blood pressure, or other diseases may fail. Treating Kidney Failure Kidney failure can be treated by dialysis. During dialysis, a machine is used to filter blood in place of the kidneys.

18. Section 10.3 Your Excretory System Slide 18 of 21 Vocabulary excretionThe process by which the body collects and removes wastes. urea A substance formed in the liver from a waste product of protein breakdown. kidney A major organ of excretion that filters wastes from the blood and produces urine. urineA watery fluid containing urea and wastes that is excreted from the body.

19. Section 10.3 Your Excretory System Slide 19 of 21 Vocabulary nephronA tiny filtering unit in the kidney that removes wastes and produces urine. glomerulus A cluster of tiny blood vessels in a nephron. dialysisA treatment for kidney failure in which a machine is used to filter wastes from blood.

20. Section 10.3 Your Excretory System Slide 20 of 21 QuickTake Quiz Click to start quiz.

21. Section 10.3 Your Excretory System Slide 21 of 21 Click above to go online. For: Chapter 10 self test

22. Section 10.3 Your Excretory System Slide 22 of 21 End of Section 10.3 Click on this slide to end this presentation.