The Kidney

• The kidney filters out waste products from the blood to create urine to be stored in the bladder.
• Osmoregulation is the regulation/balance of water throughout the body.
• When there's too little water, ADH increases, causing more water to be absorbed back into the bloodstream.
• When there's enough water, ADH decreases, allowing more water to leave the bloodstream and become urine.
• Antidiuretic hormone (ADH) regulates osmotic balance by controlling how much water is reabsorbed into the bloodstream or excreted as urine.
• The renal vein takes deoxygenated blood away from the kidney. Low in urea.
• The renal artery takes oxygenated blood to the kidney - high in urea.
• The ureter carries urine from the kidney to the bladder.
• The medulla controls selective reabsorption back into the blood from filtrate. Urine is then created from the remainder.
• Filtrate consists of urea, water, mineral ions, glucose and amino acids.
• Blood is filtered in the cortex.
• A filtering unit is known as a nephron.
• When there is a high amount of ADH, the collecting duct becomes more permeable to water reabsorption, causing a lower volume of urea concentrated urine.
• 1. Ultrafiltration - filtering of blood
  2. Selective reabsorption in medulla
  3. Kidney controls water balance using hormone ADH
• Kidney disease results in a lack of urea filtration from the blood.
• Kidney disease can damage organs over time, leading to organ failure and death.
• Kidney transplant ADVANTAGE:

  • permanent solution to kidney disease
  • more efficient filtration of urea, constant
• Kidney transplant DISADVANTAGE:

  • waiting list can be long
  • kidney can be rejected
  • must take immunosuppressants for the rest of patient's life.
• Dialysis ADVANTAGE:

  • keeps patient alive while waiting for transplant
• Dialysis DISADVANTAGE:

  • inconvenient treatment
  • painful
  • inefficient compared to new kidney
  • risk of infection
  • puncturing of blood vessels constantly
  • urea can still build up over time.