Transporting substances around the body

the circulatory system

biology

(5)

• humans have a double circulation (1=from heart to lungs for CO2 and O2 transport 2= around rest of body)
• means body can receive oxygenated blood quickly
• Arterys= carry blood away from heart, oxygenated (red), small lumen
• Veins= carry blood too heart, low in oxygen (purple), large lumen, valves to prevent back flow.
• Capilleries= deliver O2 and glucose to cells by diffusion, all over and very small,