Kidneys

• Kidney's

  A) Renal artery

  B) Renal vein

  C) Kidney

  D) Ureter

  E) Bladder

  F) Urethra

  
• Nephron

  A) Glomerulus

  B) Bowman's capsule

  C) Proximal convoluted loop

  D) Loop of henle

  E) Distal convoluted tubule

  F) Collecting duct

  
• How blood passes through the nephron:

  1. Blood goes form Glomerulus to Bowman's capsule.
  2. Only very some things can be filtered through to the Bowman's capsule. Such as water, glucose, ions, amino acids and urea.
  3. As the blood passes through the tubules selective reabsorption occurs. No urea is reabsorbed, while some ions and water are reabsorbed and all of the glucose.
  4. Then the fluid reaches the collecting duct, where it exits to be removed from body.
• Role of kidney's is to:

  • Filter blood
  • Remove waste (urea)
  • Regulate ions and water
• How water levels are regulated:

  1. Hypothalamus detects concentration of water in bloodstream.
  2. If levels are too low, then a signal is sent to the pituitary gland.
  3. The pituitary gland releases a anti-diuretic hormone (ADH).
  4. ADH travels through the body to the kidney's, telling them to reabsorb more water back into bloodstream.
  5. As a result water concentration will increase, leading to less urine.
  6. However, if levels get too high, then the hypothalamus will stop sending the signal.
  7. Therefore, the pituitary gland won't release as much ADH.
  8. Leading to more water kept in the tubules.
• Consequences of kidney failure;

  • Waste substance building up in bloodstream
  • Unable to regulate water and ion levels
• Dialysis is a machine that filters the patients blood, who has kidney failure.
• How dialysis works:

  • Blood enters the machine and goes through partially permeable membranes, which are surrounded by dialysis fluid.
  • Urea and excess ions diffuse across the membrane and leave the blood.
  • Blood continues past the membrane and back into the patient.
  • This process repeats until all blood has been filtered.
  • During this whole process the dialysis fluid is constantly change, to maintain the concentration gradient.
• Dialysis fluid is a mixture that contains the same amount of water and other molecules as healthy blood.
• Disadvantages of dialysis:

  • Time consuming (3-4 times a week for 3-4 hours)
  • Can cause blood clots and infection
  • Expensive
  • Unpleasant
  • Has to be done continually for the rest of patients life
• Disadvantages of kidney transplants:

  • Organ rejection
  • Not enough organs
• Ways to treat kidney failure:

  • Kidney transplant
  • Dialysis