The Kidneys

• What should you be able to describe by the end of the video?

  The ways water leaves the human body
• What is the role of the kidney in the body?

  Maintaining the concentration of substances in blood
• What should higher tier students explain regarding amino acids?

  How the body deals with excess amino acids
• What process was previously studied related to water movement?

  Osmosis
• What is osmosis?

  The diffusion of water across a membrane
• Why is it important to maintain water levels in the blood?

  To ensure cells work efficiently
• What happens if blood becomes too dilute?

  Water moves into cells by osmosis
• What occurs if blood becomes too concentrated?

  Water moves out of cells by osmosis
• What is homeostasis?

  The maintenance of stable internal conditions
• How does the body take in water?

  Through food and drink
• What are the three ways the body can lose water?

  Via lungs, sweat, and kidneys
• How does water loss occur via the lungs?

  When we exhale
• What does sweating involve besides water loss?

  Loss of ions and urea
• Why can't the body control water loss through sweating?

  It's part of the temperature control system
• How do kidneys contribute to water loss?

  They control how much water is lost in urine
• What do kidneys remove from the blood?

  Urea, excess ions, and excess water
• What happens to blood after it leaves the kidneys?

  It contains no urea
• What occurs during the filtration process in the kidneys?

  Small molecules are filtered out of the blood
• What is selectively absorbed in the kidneys?

  Glucose, some ions, and some water
• What happens to the concentration of glucose in the blood after passing through the kidneys?

  It remains unchanged
• How do kidneys adjust ion levels in the blood?

  By filtering and reabsorbing ions as needed
• What happens to the concentration of urea in the blood after passing through the kidneys?

  It falls to virtually zero
• What process is involved in the breakdown of excess amino acids?

  Deamination
• What toxic chemical is produced from excess amino acids?

  Ammonia
• How is ammonia dealt with in the body?

  Converted to urea by the liver
• What happens to urea after it is produced?

  It is excreted by the kidneys
• What will the next video cover?

  Water balance control and kidney dialysis
• Where can students find questions on the kidneys?

  In the revision workbook