1. The Excretory System Getting rid of metabolic wastes!

2. Excretory System: The Intro

3. Excretory System: The Function  To rid the body of wastes due to metabolic activity  This is essential to maintain homeostasis

4. Excretory System: The Video Clip

5. Excretory System: The Organs  SKIN: SKIN  Rids body of excess water and salt (SWEAT)  LUNGS: LUNGS  Rids body of CO 2  KIDNEYS:  Filter blood  Maintain blood pH  Maintain blood volume

6. Excretory System: The Kidneys  RENAL:  Refers to anything having to do with the kidneys  Kidneys involved w/ these structures:  Ureter :  Tubes that carry urine to bladder from kidneys  Urinary bladder:  Collects urine for excretion  Urethra :  Transports urine out of body from bladder

7. Kidneys: The Video Clip

8. Kidney Structure  Renal Artery:  Carries unfiltered (dirty) blood from heart TO kidneys  Renal Vein:  Carries filtered (clean) blood from kidneys TO heart  Renal Cortex:  Outer portion  Renal Medulla:  “Corn” shaped inner portion  Nephrons:  Functional unit of the kidneys!  Lie between cortex and medulla  Millions of them!

9. Excretory System: The Nephron

10.  Nephrons are the functional units of the kidney  This is where filtration, pH balance, and blood volume are maintained!  Glomerulus:  Bundle of capillaries  Bowman’s Capsule:  Surround glomerulus  Loop of Henle:  Maintains water balance  Collecting Duct:  Collects wastes from filtered blood  Connected to ureter

11. Excretory System: Nephron Process  Nephrons clean and maintain blood in 3 steps: 1.Filtration (filtering of blood): Glomerulus  PRESSURE  Bowman’s Capsule  Blood is filtered of water, urea, salts, and other materials  These filtered materials called FILTRATE 2.Reabsorption (maintaining blood volume and nutrients)  The “good” part of filtrate is reabsorbed by blood  Most filtered water re-enters blood to maintain volume 3.Secretion: (maintaining blood pH)  The “bad” part of filtrate is secreted back into filtrate  H+ ions, some water, salts, and urea  These together are called URINE!  Urination: Urine in Loop of Henle  Collecting Duct  Ureter  Bladder  Urethra

12. Excretory System: The Review