The Kidneys

• What is the primary role of the kidneys in the body?

  Water balance
• How do the kidneys regulate water balance?

  Controlling water lost/kept by the body
• What process do the kidneys use to clean the blood?

  Filtering
• Approximately what percentage of water filtered by the kidneys is reabsorbed by the body?

  99%
• Which of the following blood components are typically too large to be filtered by the kidneys?

  Blood cells and proteins
• How is glucose reabsorbed by the body from the blood in the kidneys?

  Diffusion and active transport
• What are the primary components of urine?

  Excess water, mineral ions, urea
• What substances should typically be absent from urine in a healthy individual?

  Blood cells, protein, and glucose
• What is urea?

  Waste product of protein breakdown
• What process do the kidneys employ to fine-tune the amount of water excreted as urine?

  Selective reabsorption
• Which gland releases ADH?

  Pituitary gland
• What is the effect of ADH on the kidneys?

  Reabsorb more water
• If blood water concentration is low, what happens to ADH release and kidney function?

  More ADH is released, kidneys reabsorb more
• If blood water concentration is high, what happens to ADH release and kidney function?

  Less ADH is released, kidneys reabsorb less
• How do the kidneys help restore normal blood water levels when water concentration is low?

  By reabsorbing more water
• How do the kidneys help restore normal blood water levels when water concentration is high?

  By reabsorbing less water