Compare and contrast Circulatory

• Circulatory system

  Vital for transporting nutrients, oxygen, gases and hormones and for eliminating certain waste products. In the animal kingdom there are two primary types of circulatory system: open and closed.
• Open circulatory system


  The circulatory fluid, the haemolymph, is pumped through vessels into extracellular spaces among tissues.

  The entire space filled with haemolymph is called the haemocel. This system requires less energy to maintain as it does not have an extensive blood vessel network .

  The flow of the fluid is slower however and less efficient at delivering nutrients and eliminating waste.

  Arthropods and molluscs have open circulatory systems.
• Closed circulatory system


  The circulatory fluid, the blood, exits a heart through vessels that are continuous all the way back to the intake side of the heart.

  It is more efficient at transporting substances and permits higher metabolic rates.

  However, this system is more complex and requires more energy to maintain.

  Vertebrates have a closed system and so do some invertebrates such as annelids and cephalopods.