How the Kidneys Work - #27

• What is the main role of the kidneys?

  To filter blood and remove waste
• What is the main waste product filtered by the kidneys?

  Urea
• How is urea produced in the body?

  From deamination of excess amino acids
• Why is it important to regulate ion levels in the body?

  To prevent cell damage and maintain function
• What ions do we commonly get from our diet?

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

  Through sweating
• What is the primary way the body loses water?

  Through urine produced by the kidneys
• What happens to cells when there is too much water in the body?

  They swell and may burst
• What is the process called where the kidneys filter blood?

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

  Nephrons
• What is selective reabsorption in the kidneys?

  Reabsorbing only useful substances from filtrate
• How does the analogy of cleaning a house relate to kidney function?

  It compares filtering out unwanted items
• What hormone regulates water levels in the body?

  ADH (antidiuretic hormone)
• Where is ADH released from in the body?

  The pituitary gland
• What triggers the release of ADH?

  Low water levels in the bloodstream
• What happens when ADH levels are low?

  The kidneys reabsorb less water
• What is a negative feedback loop in the context of water regulation?

  A system that maintains balance by adjusting levels
• How does the body respond if water levels are too high?

  It produces more urine to eliminate excess water
• How does the body respond if water levels are too low?

  It reabsorbs more water to increase levels
• What are the main functions of the kidneys?

  • Filter blood to remove waste products
  • Regulate levels of ions and water
• Describe the process of filtration and selective reabsorption in the kidneys.

  1. Filtration: Blood is filtered in nephrons.
  2. Selective reabsorption: Useful substances are reabsorbed.

  • Glucose and some water are reabsorbed.
  • Urea is not reabsorbed.
• Explain the role of the hypothalamus in water regulation.

  • Detects water concentration in blood.
  • Signals pituitary gland to release ADH if water is low.
• What happens to urine production when ADH levels increase?

  • More water is reabsorbed.
  • Less urine is produced.
• What happens to urine production when ADH levels decrease?

  • Less water is reabsorbed.
  • More urine is produced.