1.2.2 double and single circulatory system

Single circulatory system Fish

• Blood passes around the body ONCE for every complete circuit
• O2 is picked up at the gills and sent around the whole body in just once circuit

Double circulatory system Mammals

• Blood passes around the body TWICE for every complete circuit
• The right side of the heart takes blood to the lungs, where it picks up O2
• The blood goes to the left side of the heart where it is pumped around the body

Multicellular animals need transport systems:

• Because of their large size, so they have a low Surface area to volume ratio.
• They need constant supply of oxygen and glucose
• Theyre always active and need replacing constantly.

• Circulatory system: The two linked loops
• Pulmonary systems: Sends blood to lungs
• Systemic system: sends blood to the whole body

Advantages:

• Heart can give blood that extra push it needs. Therefore blood travels around body faster, and cells can take in the gases and nutrients in faster.