Maintaining the Body's Water Balance

• What hormone is used to control the water level in the blood?

  ADH (Antidiuretic Hormone)
• What is the primary function of the kidneys?


  To remove waste products and adjust levels of ions and water in the blood
• What process occurs in the kidneys to manage waste and water levels?


  • Filtration of water, urea, and ions from the blood
  • Selective reabsorption of water and ions back into the blood
• What happens to the body when a person exercises on a hot day?


  The body sweats to cool down, losing water in the process
• What triggers the release of ADH from the pituitary gland?


  When the blood becomes too concentrated due to low water levels
• How does ADH affect the kidneys?

  It makes the kidney tubules more permeable to water
• What happens to urine production when ADH is released?


  Less urine is produced as more water is reabsorbed
• What is a negative feedback cycle in the context of ADH and water levels?


  It is a process where the release of ADH is regulated by the concentration of water in the blood
• What occurs when a person drinks a large amount of water?

  The concentration of water in the blood rises, leading to a stop in ADH release
• What is kidney dialysis?


  A treatment that adjusts levels of water, ions, and urea in patients with kidney failure
• How does kidney dialysis work?


  The patient's blood passes over a semipermeable membrane to filter out waste
• What is the role of the semipermeable membrane in kidney dialysis?


  It allows urea, ions, and water to pass through but not larger molecules like proteins
• What is the concentration gradient in kidney dialysis?

  It is the difference in concentration of urea between the blood and dialysis fluid
• What happens to the concentrations of water and ions during dialysis?


  Some water and ions diffuse from the blood into the dialysis fluid
• What are the advantages and disadvantages of kidney dialysis?


  Advantages:

  • No shortage of dialysis machines
  • Can be performed regularly

  
  

  Disadvantages:

  • Inconvenient with frequent hospital visits
  • Requires a controlled diet
  • Long-term expensive treatment
• What are the advantages and disadvantages of kidney transplants?


  Advantages:

  • Patients can lead a normal life
  • Only expensive initially

  
  

  Disadvantages:

  • Shortage of donors
  • Risk of rejection by the immune system
  • Requires lifelong anti-rejection drugs
• What is the main waste product removed by the kidneys?


  Urea
• Why do patients on kidney dialysis need to follow a controlled diet?


  To prevent the production of excess urea
• What must kidney transplant patients take for the rest of their lives?


  Anti-rejection drugs