Open circulatory system
Blood is not carried in a system of blood vessels (e.g. insects)
Insects circulatory system
Closed circulatory system
Why is closed more efficient?
Single circulation
Earthworm single circulation
- Muscular vessels that pump blood from dorsal to ventral vessel (front and back)
Double circulation
- Separate systemic and pulmonary circulations
Pulmonary circulation
Systemic circulation
Advantages of double circulation