Ultrafiltration

• Ultra filtration


  Our body's way of removing both useful and waste products
• Ultrafiltration is essential to regulate the amount of useful and waste products in the body
• Location of ultrafiltration


  • Occurs in the Malpighian body at the beginning of the nephron
  • Consists of the glomerulus (capillary network) and Bowman's capsule
• Ultrafiltration process


  1. Blood enters glomerulus

  2. Filtrate is created and moves down the nephron

  3. Different sections of the nephron absorb or exchange useful and waste products
• Glomerulus


  • Network of blood capillaries that increase surface area for filtration
  • Has an afferent (incoming) and efferent (outgoing) arteriole
  • Afferent arteriole is wider than efferent to maintain high blood pressure (hydrostatic pressure)
• Bowman's capsule


  • Capsule that surrounds the glomerulus and collects the filtrate
• Filtration in the glomerulus and Bowman's capsule

  1. Blood enters glomerulus capillaries

  2. Substances small enough pass through endothelium pores

  3. Substances small enough then pass through podocyte slits in Bowman's capsule

  4. Substances that make it through both become part of the filtrate
• Filtrate


  Liquid produced after ultrafiltration, containing useful and waste substances, but not red blood cells or large proteins
• Filtrate is not yet urine, it changes to urine later in the nephron
• Substances that can pass through ultrafiltration

  • Urea
  • Salts
  • Glucose
  • Amino acids
• Substances that cannot pass through ultrafiltration

  • Red blood cells
  • Platelets
  • Large blood plasma proteins
• Afferent arteriole


  Artery that brings blood into the glomerulus, thick to maintain hydrostatic pressure in blood
• Efferent arteriole


  Artery that takes blood out of the glomerulus
• Hydrostatic pressure


  Pressure exerted on the walls of blood vessels by the flowing liquid
• Podocytes


  Specialised cells lining Bowman's capsule that have slits to allow filtration