B8: transport in animals

circulatory system: a system of blood vessels with a pump and valves to ensure one-way flow

Circulatory system in fish:

• 

• 2 chambered heart and single circulation

  • every 1 circuit of the body, blood passes through the heart once

Circulatory system in mammals:

• 4 chambered and double circulation

  • every 1 circuit, blood passes through the heart twice

• right side receives deoxygenated blood and pumps it into the lungs (pulmonary circulation)

• left side receives oxygenated blood from the lungs and pumps it to the body (systemic circulation)

• advantages:

  • blood travelling through the small capillaries in the lungs loses a lot of pressure