Kidneys and Kidney failure

• Cortex

  Filters large molecules from the blood
• Pelvis

  Collects urine
• Medulla

  Contains nephrons where water, salt and urea are removed from the blood
• Renal artery

  Brings blood to the kidney
• Renal vein

  Takes blood away from the kidney
• Ureter

  Takes urine from kidney to blader
• How do kidneys filter blood?

  • Blood enters the kidneys via the renal artery
  • Glucose, water, mineral ions + waste products filtered out of blood into kidney
  • As the filtrate moves through the kidneys all of the glucose is reabsorbed by diffusion or active transport
  • Some water and mineral ions are also reabsorbed, the amounts change based on what your body needs this is called selective reabsorption
  • The filtrate is now urine which passes into the pelvis and leaves the kidneys via the ureter
• What hormone controls water balance?

  ADH (Antidiuretic hormone)
• Where is ADH produced and released?

  pituitary gland
• Explain what happens if the blood becomes too concentrated with solutes?

  • More ADH is released
  • Kidney tubules reabsorb more water
  • little urine produced
  • Blood restored back to normal
• Explain what happens if the blood solute concentration is too dilute?

  • Less ADH is released
  • Kidney tubules reabsorb less water 
  • lots of urine produced
  • Blood restored back to normal
• How does dialysis work?

  • Blood leaves the patient
  • Flows between partially permeable membranes
  • Dialysis fluid is on the other side of the membrane
  • This cleans or filters the blood
  • Passes through bubble trap
  • Blood re-enters the patient
• Explain how dialysis weeks to make sure that levels of glucose and mineral ions are correct?

  • Dialysis fluid contains some concentration of glucose and mineral ions as healthy blood
  • No net movement of glucose
  • If blood contains more than normal levels of mineral ions (excess) they diffuse out of blood down a concentration gradient
• Explain how dialysis works to remove urea/toxins?

  • Dialysis fluid contains no urea
  • creates a steep concentration gradient
  • urea diffuses out of the blood down a concentration gradient
• List the pros of dialysis

  • Does the job of the kidneys
  • Keeps people alive
  • Readily available
• List the cons of dialysis

  • Takes around 8 hours each time
  • Need several times a week
  • Patients must have a carful diet, control protein and salt intake
  • May feel tired or unwell in between sessions
  • Balance becomes more difficult over many years
  • Risk of infection
  • Risk of blood clots
  • Expensive
• List the pros of kidney transplants

  • Gives people a functioning kidney
  • Keeps people alive
  • No restrictions- not time consuming/can eat and drink normally
  • Cheaper
• List the cons of kidney transplants

  • Risk of rejection
  • Patients must take immunosuppressant drugs for the rest of their lives
  • Drugs can weaken the patients immune system
  • Need regular check ups
  • Only lasts around 9 years
  • Not readily available
  • Risk of operation/ anaesthetics/infections
• carbon dioxide (as a waste product)

  • produced during cellular respiration
  • it is removed as it would lower the Ph of cytoplasm so enzymes would not work
  • it is removed by being carried through the blood to the lungs where it diffuses into the alveoli and is exhaled
• Urea

  • produced in the liver through breakdown of excess amino acid
  • it is removed as it is poisonous and would cause damage to cells if left in the blood
• controlled loss

  removal by the kidney then excreted as urine - this removes urea and maintains water and mineral content of the blood
• uncontrolled loss

  • water leaving the lungs during exhalation
  • water and mineral ions lost in sweat
• What is C?

  Renal pelvis

  
• Label diagram

  A) Cortex

  B) Medulla

  C) renal artery

  D) renal vein

  E) ureter

  F) renal pelvis