Kidneys

• What is the main role of the kidneys?


  To filter the blood and remove waste products
• What is the main waste product that the kidneys remove?

  Urea
• How is urea produced in the body?


  It is made in the liver during deamination of excess amino acids
• What happens to excess amino acids in the body?


  They are converted to fats and carbohydrates for storage
• Why is it important to regulate ion levels in the body?


  Because imbalances can damage cells and cause problems
• What ions do we commonly get from our diet?

  Sodium and potassium ions
• How do we lose ions from our body?


  We lose some ions naturally during sweating
• What is the main way we regulate our water levels?

  Through the kidneys in the form of urine
• How does osmosis affect cells in relation to water levels?


  Cells can swell or shrink depending on water levels
• What is the process called where the kidneys filter blood?

  Filtration
• What structures in the kidneys are responsible for filtering blood?

  Nephrons
• What is the function of the kidney tubules during filtration?


  They absorb small substances like water, glucose, and amino acids
• What is selective reabsorption in the kidneys?


  It is the process of reabsorbing only the substances the body needs
• How can you think of selective reabsorption in the kidneys?


  Like cleaning out a house and only bringing back what you want to keep
• What hormone is involved in regulating water levels in the body?

  ADH (antidiuretic hormone)
• Where is ADH released from?


  The pituitary gland
• What triggers the release of ADH?


  Low water levels in the body
• What effect does ADH have on the kidneys?


  It tells the kidneys to reabsorb more water into the blood
• What happens when water levels in the bloodstream are too high?

  The hypothalamus reduces the release of ADH
• What is the result of less ADH in the bloodstream?


  The kidneys produce more urine
• What is the process of water regulation in the body?

  • Hypothalamus detects water concentration
  • If low, signals pituitary gland to release ADH
  • ADH increases water reabsorption in kidneys
  • If high, hypothalamus reduces ADH release
  • Kidneys produce more urine to eliminate excess water
• What is the negative feedback loop in water regulation?


  • Body monitors water levels
  • If too high, reduces ADH to lower levels
  • If too low, increases ADH to raise levels
  • Maintains balance of water levels in the body