Blood speed

[fatalbert]

At what speed does blood travel around our bodies.Say for a healthy 35 year old with average blood pressure.This is just idle curiosity on my part ,i have always wanted to know ever since seeing The Fantastic voyage as a kid.Thanks ....Neil

[brachiopod]

Sorry for the short answer - but just lost the long, involved one TWICE now by accidentally clicking on one of these bloody adverts to the right.

Anyway - speed is pretty meaningless - depends on the diameter of the vein / artery / capillary and the blood flow rate.

Which is about 0.00007777 cubic metres per second (or "cumecs" - the SI unit of flow)

Compare this with the lower reaches of the amazon, which flows at a rate of some 120 000 cubic metres per second, yet the longitutinal 'flow' can be as little as a couple of kilometeres per hour. Why? Because it is so wide, an enormous volume of water takes a long time to pass by.

In your blood vessels, the flow varies with distance from the heart, vascular heirachy, and the diameter of the vessel itself, so "speed" becomes pretty meaningless.

[wildwood]

Notwithstanding the lampshell's answer, it must flow pretty fast because an injection in your arm reaches your brain in 3 seconds.

If the Proteus would have really travelled at that relative speed, it would have certainly knocked Raquel on her pretty botty and rattled her brain to a pulp.

[tasdenton]

brachiopod answer can't be quit true because then by definition then blood travels on average at aproximatly 31.74885699m/hr not exactly fast enough for life
now if the blood travel from the arm to the brain in 3s and it traveled just 10m through blood vesels to the heart to the lungs to the heart to the brain than that puts it at a speed of 3 1/3 m/s baised on the aproximation given by brachopod and the formular ave speed=distance/time: 10/8.181926941*10^-3m/s
states that it would take 1133.899089s to cover the same distance 10 m. 10m would be covered in over 18hr hardly concurent results or fast enough for life

[katsass1212]

BLOOD SPEED VARIES, because the vessels that carry the blood vary greatly in diameter.

very slow - capillaries
faster - veins
fastest - arteries

That answer stinks though, cause everybody wants to know MPH! or something that they can relate to, right? So...
The average speed that blood travels through the body is aproximately 5 feet per second / 3 mph. A comfortable walking speed.