Discover the warning signs of circulatory problems, from buttock pain to slow-healing wounds, plus the foods and activities ...

Each 2.54 square centimetre (a square inch) of human skin has six metres (20ft) of blood vessels. Veins hold about 65 per cent of the body's blood and have one-way valves tohelp blood move.

A bioreactor that mimics a circulatory system can deliver nutrients ... "We're using semipermeable hollow fibers, which mimic blood vessels in their ability to deliver nutrients to the tissues ...

lungs and blood vessels and back to the heart. Nearly half the population is blood type O, and can donate blood to people of all other blood groups but can receive only Type O themselves.