Kidneys in Homeostasis

• What are the functions of the kidneys?

  • regulate water and salt content
  • remove waste products
• What are the features of the excretory system?

  Kidneys, ureters, bladder, urethra, vena cava, aorta, renal vein and renal artery
• What do the kidneys do?

  Regulate water content and filters blood
• What does the ureter do?

  Carriers urine from the kidneys to the bladder
• What does the bladder do?

  Stores urine
• What does the urethra do?

  Excretes urine.
• What does the renal artery do?

  Brings unfiltered blood to the kidneys
• What’s does the renal vein do?

  Takes clean blood from the kidney
• What is the process of the excretory system?

  1. Blood is brought by the renal artery
  2. Kidney controls water and salt and removes urea
  3. excess water, salt and urea turn into urine
  4. Urine is transported to bladder by ureters
  5. Bladder stores urine
  6. Clean blood returns by renal vein
• What are the features of the nephron?

  Arterioles, capillary knot, bowman's capsule, tubule, capillary network, collecting duct
• What does the high pressure in the capillary knot result in?

  Ultrafiltration
• What is removed by ultrafiltration in the nephron?

  Everything but glucose, salts and water
• What is the tubule responsible for?

  Selective reabsorption of glucose, some salts and water
• What is the collecting duct responsible for?

  Selective reabsorption of most water
• What does the cortex do?

  Filters large molecules
• What does the medulla do?

  Where water, salt and urea are removed from blood
• Why is it important that urea is removed from the blood?

  It’s toxic
• What does the pelvis do?

  Collects urine
• What does the anti diuretic hormone do?

  Controls the water content of the blood
• What happens when H2O content is low in the blood?

  1. Hypothalamus (brain) detects content is low
  2. Pituitary gland secretes ADH
  3. Travels to collecting duct
  4. Aquaporins inserted into the collecting duct
  5. Water exists by osmosis
  6. Low volume of urine and dark in colour
• What happens when H2O content is high in blood?

  The process is reversed and urine is high in volume and light in colour
• What can be detected using urine?

  Certain diseases
• What does glucose in the urine indicate?

  Diabetes
• What does protein in the urine indicate?

  Damage in the kidneys
• What can be done if you have kidney disease?

  Kidney dialysis or a kidney transplant
• What does kidney dialysis do?

  Removes toxic urea and maintains balance of salts and water in the blood
• What are the advantages of kidney dialysis?

  • Keeps you alive
  • Doesn't involve major surgery
• What are the disadvantages of kidney dialysis?

  • Have to control diet
  • Hours attached to the machine a week
  • Expensive
  • Short term fix
• How does kidney dialysis work?

  • Dirty blood is taken from the patient and put into a dialyser
  • Dialysis fluid is inserted and removes waste from the blood through a semi permeable membrane
  • Clean blood is returned to the patient
• What is a kidney transplant?

  Replacing the failing kidney with a healthy one from a donor
• Where is the donor kidney attached?

  Near the bladder
• Do they remove the original kidneys in a transplant?

  No
• What can happen to donor kidneys?

  They can be rejected- an immune response happens and destroys the kidney
• What are the advantages of a kidney transplant?

  • No diet restrictions
  • No more dialysis
  • Better life
• What are the disadvantages of a kidney transplant?

  • Difficult to find a donor
  • Risk of rejection
  • Have to take immunosuppressants
  • Major surgery required
• What do the blood and dialysis fluid move in?

  Opposite directions to maintain the concentration gradient
• What is the system in a dialysis machine to keep the blood and dialysis fluid in opposite directions?

  Concurrent system