excretion

• What are the functional units of the kidney called?

  Nephrons
• What is the outermost area of the kidney?

  Cortex

  
• What is the inner area of the kidney called?

  Medulla
• How is blood transported to the kidney?

  Through the renal artery
• Where is the glomerulus located?

  At the beginning of the nephron
• What surrounds the glomerulus?

  Capillaries branching from the renal artery
• What substances are filtered out in the glomerulus?

  Glucose, water, urea, and ions
• What happens to useful substances along the nephron?

  They are reabsorbed back into the blood
• What percentage of glucose is reabsorbed in the nephron?

  All of the glucose
• What is reabsorbed along with glucose in the nephron?

  Some ions and most of the water
• How does blood return to the heart from the nephron?

  Via the renal vein
• What does the remaining fluid in the nephron consist of?

  Excess water, urea, and excess ions
• What is formed from the remaining fluid in the nephron?

  Urine
• Why is urea removed from the body?

  To prevent toxic levels in the body
• What is the process of urine formation in the nephron?

  1. Blood enters the glomerulus.
  2. Filtration occurs (glucose, water, urea, ions).
  3. Reabsorption of glucose, ions, and water.
  4. Remaining fluid forms urine.
  5. Urea is excreted to prevent toxicity.