Kidney Failure

• most common causes

  • diabetes
  • hypertension (high blood pressure)
  • infection
• effects


  unable to remove

  • urea
  • excess water
  • excess salts

  or regulate water and salt levels
• effects of causes on ultrafiltration

  diabetes: high blood sugar levels can damage blood vessels and nephrons

  infection: can lead to damage of tubule cells and podocytes

  hypertension: leads to damage to basement membrane and epithelial cells
• glomerular filtrate rate (GMF)

  • the rate at which fluid is filtered from the glomerulus into Bowman's
  • lowers with age
  • a low rate indicates kidneys aren't working effectively
  • measured using a blood test for creatinine, which is a product of muscle breakdown
  • high levels of creatinine may suggest filtration not working effectively
• treatments


  haemodialysis and transplantation
• haemodialysis


  • blood leaves body through artery
  • enters dialysis machine, and flows between partially permeable membranes, with dialysis fluid on either side
  • important that urea exits, but other substances remain in the blood
• dialysis fluid make up

  • normal glucose levels
  • normal mineral ion levels
  • no urea
  • similar concentrations to blood
• disadvantages of haemodialysis

  • carefully managed diet, low protein and salts
  • lengthy process, 8 hours
  • needs to be repeated regularly
  • takes away quality of life, revolves around dialysis
• transplants


  replacing an unhealthy/infected kidney, with a donated healthy one
• disadvantages of transplants

  • risk of rejection, antigens on donor and recipient do not match and immune system recognises this
  • have to take immunosuppressants
  • transplants only last 9-10 years on average, but may last longer
  • may be shortage of donors