• Question: How many blood vessels are there in the human body?

    Asked by issiphee1 to Iain, Jo, Leo on 24 Jun 2010 in Categories: .
    • Photo: Leo Garcia

      Leo Garcia answered on 24 Jun 2010:

      In an average 70 kg male, there may be up to 100,000 miles of circulatory system inside (if the vessels were laid end to end) – that’s enough to go round the world 4 times!

      There are 3 major types of blood vessel: arteries, which carry the blood away from the heart; capillaries, which enable water and chemicals to go between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.

Comments

  • Photo: issiphee1

    issiphee1 commented on :

    How do we know the length of all the blood vessels? Did somebody cut all of them out and measure it? I know it sounds stupid but I have always wondered..

    • Photo: Leo

      Leo commented on :

      I think that the length that I have stated has not come from a direct measurement – but instead an estimate based on several simplifying assumptions, such as height, weight etc… Good question though – I can’t say I thought of it when I wrote the answer!