1. Kidney Filtration Lab

2. Objectives Determine how kidneys function Identify components of the blood that should be removed by the kidneys Identify components of blood that should not be present in the urine

3. What Do Kidneys Do? Maintain HOMEOSTASIS Remove UREA and other waste Regulate the amount of WATER in the blood Adjust the CONCENTRATION of other substances in the blood Send FILTERED blood back throughout the body

4. Blood Components The following items are found in the bloodstream:  Water  Red Blood Cells  White Blood Cells  Glucose  Protein  Amino Acids  Salt  Urea

5. Blood Components As blood goes through the kidneys, some components of blood are  Kept: because they are ESSENTIAL for life functions  Removed: and EXCRETED in the urine because they are TOXIC  Balanced: so they are present in the correct AMOUNT in the blood  COMPLETELY reabsorbed (KEEP them all)  SELECTIVELY reabsorbed (KEEP a certain amount as needed)

6. Blood Components Blood ComponentAction Taken By Kidneys WaterBalanced (Selectively Reabsorbed) Red Blood CellsKept White Blood CellsKept GlucoseBalanced (Completely Reabsorbed) ProteinKept Amino AcidsBalanced (Completely Reabsorbed) SaltBalanced (Selectively Reabsorbed UreaRemoved

7. Kidney Diagram

8. How Kidneys Work Blood enters the kidneys through the RENAL ARTERY Blood branches out to small capillaries (called GLOMERULUS) Big particles stay in the blood  Red Blood Cells  White Blood Cells  Proteins Small particles go into a holding area (called the NEPHRON)

9. How Kidneys Work The material in the nephron is called FILTRATE The body REABSORBS some (selectively) or all (completely) of the materials required for homeostasis The remaining filtrate is sent to the bladder as URINE