The Kidney

• Kidneys

  • essential in maintaining a constant internal environment and play an important role in osmoregulation
  • remove nitrogenous wastes
  • regulate water concentration in blood
  • maintain ion levels in blood
• Antidiuretic Hormone (ADH)

  • controls the maintenance of water balance in mammals - reduces urine output by acting on collecting ducts
  • produced in the hypothalamus and stored in the pituitary gland
  • main function of collecting ducts = reabsorb water and carry urine to the ureter to be transported to the bladder
  • ADH increases reabsorption of water in the collecting ducts
• Size of Proximal Convolution

  • long = maximum water reabsorption
  • short = minimum water reabsorption
• Size of Glomerulus and Bowman's Capsule

  • large = maximum filtration
  • small = minimum filtration
• Size of Loop of Henle

  Water is conserved when it's reabsorbed in the descending loop of henle

  • large = promotes water reabsorption
  • small = reduces water reabsorption
• Degree of Vascularisation

  • heavy = more reabsorption
  • light = less reabsorption