Large multicellular animals

• Horse

  -          Closed system to pump blood all over body,

  -          Every cell recieves nutrients and oxygen

  
• Bee

  -          Open system, leaves the end of vessels to bathe tissues with nutrients

  
• Open circulatory system


  Transport fluid (haemolymph) leaves the vessels and comes in direct contact with cells in tissues to give them nutrients

  
• closed circulatory system


  always stays in vessels and never comes in contact with cells for exchange of materials

  
• Interstitial fluid


  The fluid that surrounds and bathes the cells.

  • does not contain red blood cells, these remain in the capillaries
  • cells take up nutrients from it and release wastes into it